Revision 6c65bf1743a3d558e5806597c60b532160a37655 authored by akankshamahajan on 07 March 2023, 23:07:49 UTC, committed by Facebook GitHub Bot on 07 March 2023, 23:07:49 UTC
Summary:
Internally, the benchmark is going on hang state whereas when run on same host manually, it passes. Decrease the duration to 5s to figure out how much time it is taking to complete the benchmark.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11283

Test Plan: Ran manually internally

Reviewed By: hx235

Differential Revision: D43882260

Pulled By: akankshamahajan15

fbshipit-source-id: 9ea44164773d4df4fc05cd817b7e011426c4d428
1 parent e010732
Raw File
db_stress_test_base.cc
//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
//  This source code is licensed under both the GPLv2 (found in the
//  COPYING file in the root directory) and Apache 2.0 License
//  (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
//

#include <ios>
#include <thread>

#include "util/compression.h"
#ifdef GFLAGS
#include "db_stress_tool/db_stress_common.h"
#include "db_stress_tool/db_stress_compaction_filter.h"
#include "db_stress_tool/db_stress_driver.h"
#include "db_stress_tool/db_stress_table_properties_collector.h"
#include "rocksdb/convenience.h"
#include "rocksdb/filter_policy.h"
#include "rocksdb/secondary_cache.h"
#include "rocksdb/sst_file_manager.h"
#include "rocksdb/types.h"
#include "rocksdb/utilities/object_registry.h"
#include "rocksdb/utilities/write_batch_with_index.h"
#include "test_util/testutil.h"
#include "util/cast_util.h"
#include "utilities/backup/backup_engine_impl.h"
#include "utilities/fault_injection_fs.h"
#include "utilities/fault_injection_secondary_cache.h"

namespace ROCKSDB_NAMESPACE {

namespace {

std::shared_ptr<const FilterPolicy> CreateFilterPolicy() {
  if (FLAGS_bloom_bits < 0) {
    return BlockBasedTableOptions().filter_policy;
  }
  const FilterPolicy* new_policy;
  if (FLAGS_ribbon_starting_level >= 999) {
    // Use Bloom API
    new_policy = NewBloomFilterPolicy(FLAGS_bloom_bits, false);
  } else {
    new_policy = NewRibbonFilterPolicy(
        FLAGS_bloom_bits, /* bloom_before_level */ FLAGS_ribbon_starting_level);
  }
  return std::shared_ptr<const FilterPolicy>(new_policy);
}

}  // namespace

StressTest::StressTest()
    : cache_(NewCache(FLAGS_cache_size, FLAGS_cache_numshardbits)),
      filter_policy_(CreateFilterPolicy()),
      db_(nullptr),
      txn_db_(nullptr),

      db_aptr_(nullptr),
      clock_(db_stress_env->GetSystemClock().get()),
      new_column_family_name_(1),
      num_times_reopened_(0),
      db_preload_finished_(false),
      cmp_db_(nullptr),
      is_db_stopped_(false) {
  if (FLAGS_destroy_db_initially) {
    std::vector<std::string> files;
    db_stress_env->GetChildren(FLAGS_db, &files);
    for (unsigned int i = 0; i < files.size(); i++) {
      if (Slice(files[i]).starts_with("heap-")) {
        db_stress_env->DeleteFile(FLAGS_db + "/" + files[i]);
      }
    }

    Options options;
    options.env = db_stress_env;
    // Remove files without preserving manfiest files
    const Status s = !FLAGS_use_blob_db
                         ? DestroyDB(FLAGS_db, options)
                         : blob_db::DestroyBlobDB(FLAGS_db, options,
                                                  blob_db::BlobDBOptions());

    if (!s.ok()) {
      fprintf(stderr, "Cannot destroy original db: %s\n", s.ToString().c_str());
      exit(1);
    }
  }
}

StressTest::~StressTest() {
  for (auto cf : column_families_) {
    delete cf;
  }
  column_families_.clear();
  delete db_;

  for (auto* cf : cmp_cfhs_) {
    delete cf;
  }
  cmp_cfhs_.clear();
  delete cmp_db_;
}

std::shared_ptr<Cache> StressTest::NewCache(size_t capacity,
                                            int32_t num_shard_bits) {
  ConfigOptions config_options;
  if (capacity <= 0) {
    return nullptr;
  }

  if (FLAGS_cache_type == "clock_cache") {
    fprintf(stderr, "Old clock cache implementation has been removed.\n");
    exit(1);
  } else if (FLAGS_cache_type == "hyper_clock_cache") {
    return HyperClockCacheOptions(static_cast<size_t>(capacity),
                                  FLAGS_block_size /*estimated_entry_charge*/,
                                  num_shard_bits)
        .MakeSharedCache();
  } else if (FLAGS_cache_type == "lru_cache") {
    LRUCacheOptions opts;
    opts.capacity = capacity;
    opts.num_shard_bits = num_shard_bits;
    std::shared_ptr<SecondaryCache> secondary_cache;
    if (!FLAGS_secondary_cache_uri.empty()) {
      Status s = SecondaryCache::CreateFromString(
          config_options, FLAGS_secondary_cache_uri, &secondary_cache);
      if (secondary_cache == nullptr) {
        fprintf(stderr,
                "No secondary cache registered matching string: %s status=%s\n",
                FLAGS_secondary_cache_uri.c_str(), s.ToString().c_str());
        exit(1);
      }
      if (FLAGS_secondary_cache_fault_one_in > 0) {
        secondary_cache = std::make_shared<FaultInjectionSecondaryCache>(
            secondary_cache, static_cast<uint32_t>(FLAGS_seed),
            FLAGS_secondary_cache_fault_one_in);
      }
      opts.secondary_cache = secondary_cache;
    }

    return NewLRUCache(opts);
  } else {
    fprintf(stderr, "Cache type not supported.");
    exit(1);
  }
}

std::vector<std::string> StressTest::GetBlobCompressionTags() {
  std::vector<std::string> compression_tags{"kNoCompression"};

  if (Snappy_Supported()) {
    compression_tags.emplace_back("kSnappyCompression");
  }
  if (LZ4_Supported()) {
    compression_tags.emplace_back("kLZ4Compression");
  }
  if (ZSTD_Supported()) {
    compression_tags.emplace_back("kZSTD");
  }

  return compression_tags;
}

bool StressTest::BuildOptionsTable() {
  if (FLAGS_set_options_one_in <= 0) {
    return true;
  }

  std::unordered_map<std::string, std::vector<std::string>> options_tbl = {
      {"write_buffer_size",
       {std::to_string(options_.write_buffer_size),
        std::to_string(options_.write_buffer_size * 2),
        std::to_string(options_.write_buffer_size * 4)}},
      {"max_write_buffer_number",
       {std::to_string(options_.max_write_buffer_number),
        std::to_string(options_.max_write_buffer_number * 2),
        std::to_string(options_.max_write_buffer_number * 4)}},
      {"arena_block_size",
       {
           std::to_string(options_.arena_block_size),
           std::to_string(options_.write_buffer_size / 4),
           std::to_string(options_.write_buffer_size / 8),
       }},
      {"memtable_huge_page_size", {"0", std::to_string(2 * 1024 * 1024)}},
      {"max_successive_merges", {"0", "2", "4"}},
      {"inplace_update_num_locks", {"100", "200", "300"}},
      // TODO: re-enable once internal task T124324915 is fixed.
      // {"experimental_mempurge_threshold", {"0.0", "1.0"}},
      // TODO(ljin): enable test for this option
      // {"disable_auto_compactions", {"100", "200", "300"}},
      {"level0_file_num_compaction_trigger",
       {
           std::to_string(options_.level0_file_num_compaction_trigger),
           std::to_string(options_.level0_file_num_compaction_trigger + 2),
           std::to_string(options_.level0_file_num_compaction_trigger + 4),
       }},
      {"level0_slowdown_writes_trigger",
       {
           std::to_string(options_.level0_slowdown_writes_trigger),
           std::to_string(options_.level0_slowdown_writes_trigger + 2),
           std::to_string(options_.level0_slowdown_writes_trigger + 4),
       }},
      {"level0_stop_writes_trigger",
       {
           std::to_string(options_.level0_stop_writes_trigger),
           std::to_string(options_.level0_stop_writes_trigger + 2),
           std::to_string(options_.level0_stop_writes_trigger + 4),
       }},
      {"max_compaction_bytes",
       {
           std::to_string(options_.target_file_size_base * 5),
           std::to_string(options_.target_file_size_base * 15),
           std::to_string(options_.target_file_size_base * 100),
       }},
      {"target_file_size_base",
       {
           std::to_string(options_.target_file_size_base),
           std::to_string(options_.target_file_size_base * 2),
           std::to_string(options_.target_file_size_base * 4),
       }},
      {"target_file_size_multiplier",
       {
           std::to_string(options_.target_file_size_multiplier),
           "1",
           "2",
       }},
      {"max_bytes_for_level_base",
       {
           std::to_string(options_.max_bytes_for_level_base / 2),
           std::to_string(options_.max_bytes_for_level_base),
           std::to_string(options_.max_bytes_for_level_base * 2),
       }},
      {"max_bytes_for_level_multiplier",
       {
           std::to_string(options_.max_bytes_for_level_multiplier),
           "1",
           "2",
       }},
      {"max_sequential_skip_in_iterations", {"4", "8", "12"}},
  };

  if (FLAGS_allow_setting_blob_options_dynamically) {
    options_tbl.emplace("enable_blob_files",
                        std::vector<std::string>{"false", "true"});
    options_tbl.emplace("min_blob_size",
                        std::vector<std::string>{"0", "8", "16"});
    options_tbl.emplace("blob_file_size",
                        std::vector<std::string>{"1M", "16M", "256M", "1G"});
    options_tbl.emplace("blob_compression_type", GetBlobCompressionTags());
    options_tbl.emplace("enable_blob_garbage_collection",
                        std::vector<std::string>{"false", "true"});
    options_tbl.emplace(
        "blob_garbage_collection_age_cutoff",
        std::vector<std::string>{"0.0", "0.25", "0.5", "0.75", "1.0"});
    options_tbl.emplace("blob_garbage_collection_force_threshold",
                        std::vector<std::string>{"0.5", "0.75", "1.0"});
    options_tbl.emplace("blob_compaction_readahead_size",
                        std::vector<std::string>{"0", "1M", "4M"});
    options_tbl.emplace("blob_file_starting_level",
                        std::vector<std::string>{"0", "1", "2"});
    options_tbl.emplace("prepopulate_blob_cache",
                        std::vector<std::string>{"kDisable", "kFlushOnly"});
  }

  options_table_ = std::move(options_tbl);

  for (const auto& iter : options_table_) {
    options_index_.push_back(iter.first);
  }
  return true;
}

void StressTest::InitDb(SharedState* shared) {
  uint64_t now = clock_->NowMicros();
  fprintf(stdout, "%s Initializing db_stress\n",
          clock_->TimeToString(now / 1000000).c_str());
  PrintEnv();
  Open(shared);
  BuildOptionsTable();
}

void StressTest::FinishInitDb(SharedState* shared) {
  if (FLAGS_read_only) {
    uint64_t now = clock_->NowMicros();
    fprintf(stdout, "%s Preloading db with %" PRIu64 " KVs\n",
            clock_->TimeToString(now / 1000000).c_str(), FLAGS_max_key);
    PreloadDbAndReopenAsReadOnly(FLAGS_max_key, shared);
  }

  if (shared->HasHistory()) {
    // The way it works right now is, if there's any history, that means the
    // previous run mutating the DB had all its operations traced, in which case
    // we should always be able to `Restore()` the expected values to match the
    // `db_`'s current seqno.
    Status s = shared->Restore(db_);
    if (!s.ok()) {
      fprintf(stderr, "Error restoring historical expected values: %s\n",
              s.ToString().c_str());
      exit(1);
    }
  }
  if (FLAGS_use_txn) {
    // It's OK here without sync because unsynced data cannot be lost at this
    // point
    // - even with sync_fault_injection=1 as the
    // file is still directly writable until after FinishInitDb()
    ProcessRecoveredPreparedTxns(shared);
  }

  if (FLAGS_enable_compaction_filter) {
    auto* compaction_filter_factory =
        reinterpret_cast<DbStressCompactionFilterFactory*>(
            options_.compaction_filter_factory.get());
    assert(compaction_filter_factory);
    // This must be called only after any potential `SharedState::Restore()` has
    // completed in order for the `compaction_filter_factory` to operate on the
    // correct latest values file.
    compaction_filter_factory->SetSharedState(shared);
    fprintf(stdout, "Compaction filter factory: %s\n",
            compaction_filter_factory->Name());
  }
}

void StressTest::TrackExpectedState(SharedState* shared) {
  // For `FLAGS_manual_wal_flush_one_inWAL`
  // data can be lost when `manual_wal_flush_one_in > 0` and `FlushWAL()` is not
  // explictly called by users of RocksDB (in our case, db stress).
  // Therefore recovery from such potential WAL data loss is a prefix recovery
  // that requires tracing
  if ((FLAGS_sync_fault_injection || FLAGS_disable_wal ||
       FLAGS_manual_wal_flush_one_in > 0) &&
      IsStateTracked()) {
    Status s = shared->SaveAtAndAfter(db_);
    if (!s.ok()) {
      fprintf(stderr, "Error enabling history tracing: %s\n",
              s.ToString().c_str());
      exit(1);
    }
  }
}

Status StressTest::AssertSame(DB* db, ColumnFamilyHandle* cf,
                              ThreadState::SnapshotState& snap_state) {
  Status s;
  if (cf->GetName() != snap_state.cf_at_name) {
    return s;
  }
  // This `ReadOptions` is for validation purposes. Ignore
  // `FLAGS_rate_limit_user_ops` to avoid slowing any validation.
  ReadOptions ropt;
  ropt.snapshot = snap_state.snapshot;
  Slice ts;
  if (!snap_state.timestamp.empty()) {
    ts = snap_state.timestamp;
    ropt.timestamp = &ts;
  }
  PinnableSlice exp_v(&snap_state.value);
  exp_v.PinSelf();
  PinnableSlice v;
  s = db->Get(ropt, cf, snap_state.key, &v);
  if (!s.ok() && !s.IsNotFound()) {
    return s;
  }
  if (snap_state.status != s) {
    return Status::Corruption(
        "The snapshot gave inconsistent results for key " +
        std::to_string(Hash(snap_state.key.c_str(), snap_state.key.size(), 0)) +
        " in cf " + cf->GetName() + ": (" + snap_state.status.ToString() +
        ") vs. (" + s.ToString() + ")");
  }
  if (s.ok()) {
    if (exp_v != v) {
      return Status::Corruption("The snapshot gave inconsistent values: (" +
                                exp_v.ToString() + ") vs. (" + v.ToString() +
                                ")");
    }
  }
  if (snap_state.key_vec != nullptr) {
    // When `prefix_extractor` is set, seeking to beginning and scanning
    // across prefixes are only supported with `total_order_seek` set.
    ropt.total_order_seek = true;
    std::unique_ptr<Iterator> iterator(db->NewIterator(ropt));
    std::unique_ptr<std::vector<bool>> tmp_bitvec(
        new std::vector<bool>(FLAGS_max_key));
    for (iterator->SeekToFirst(); iterator->Valid(); iterator->Next()) {
      uint64_t key_val;
      if (GetIntVal(iterator->key().ToString(), &key_val)) {
        (*tmp_bitvec.get())[key_val] = true;
      }
    }
    if (!std::equal(snap_state.key_vec->begin(), snap_state.key_vec->end(),
                    tmp_bitvec.get()->begin())) {
      return Status::Corruption("Found inconsistent keys at this snapshot");
    }
  }
  return Status::OK();
}

void StressTest::VerificationAbort(SharedState* shared, std::string msg,
                                   Status s) const {
  fprintf(stderr, "Verification failed: %s. Status is %s\n", msg.c_str(),
          s.ToString().c_str());
  shared->SetVerificationFailure();
}

void StressTest::VerificationAbort(SharedState* shared, std::string msg, int cf,
                                   int64_t key) const {
  auto key_str = Key(key);
  Slice key_slice = key_str;
  fprintf(stderr,
          "Verification failed for column family %d key %s (%" PRIi64 "): %s\n",
          cf, key_slice.ToString(true).c_str(), key, msg.c_str());
  shared->SetVerificationFailure();
}

void StressTest::VerificationAbort(SharedState* shared, std::string msg, int cf,
                                   int64_t key, Slice value_from_db,
                                   Slice value_from_expected) const {
  auto key_str = Key(key);
  fprintf(stderr,
          "Verification failed for column family %d key %s (%" PRIi64
          "): value_from_db: %s, value_from_expected: %s, msg: %s\n",
          cf, Slice(key_str).ToString(true).c_str(), key,
          value_from_db.ToString(true).c_str(),
          value_from_expected.ToString(true).c_str(), msg.c_str());
  shared->SetVerificationFailure();
}

void StressTest::VerificationAbort(SharedState* shared, int cf, int64_t key,
                                   const Slice& value,
                                   const WideColumns& columns,
                                   const WideColumns& expected_columns) const {
  assert(shared);

  auto key_str = Key(key);

  fprintf(stderr,
          "Verification failed for column family %d key %s (%" PRIi64
          "): Value and columns inconsistent: %s\n",
          cf, Slice(key_str).ToString(/* hex */ true).c_str(), key,
          DebugString(value, columns, expected_columns).c_str());

  shared->SetVerificationFailure();
}

std::string StressTest::DebugString(const Slice& value,
                                    const WideColumns& columns,
                                    const WideColumns& expected_columns) {
  std::ostringstream oss;

  oss << "value: " << value.ToString(/* hex */ true);

  auto dump = [](const WideColumns& cols, std::ostream& os) {
    if (cols.empty()) {
      return;
    }

    os << std::hex;

    auto it = cols.begin();
    os << *it;
    for (++it; it != cols.end(); ++it) {
      os << ' ' << *it;
    }
  };

  oss << ", columns: ";
  dump(columns, oss);

  oss << ", expected_columns: ";
  dump(expected_columns, oss);

  return oss.str();
}

void StressTest::PrintStatistics() {
  if (dbstats) {
    fprintf(stdout, "STATISTICS:\n%s\n", dbstats->ToString().c_str());
  }
  if (dbstats_secondaries) {
    fprintf(stdout, "Secondary instances STATISTICS:\n%s\n",
            dbstats_secondaries->ToString().c_str());
  }
}

// Currently PreloadDb has to be single-threaded.
void StressTest::PreloadDbAndReopenAsReadOnly(int64_t number_of_keys,
                                              SharedState* shared) {
  WriteOptions write_opts;
  write_opts.disableWAL = FLAGS_disable_wal;
  if (FLAGS_sync) {
    write_opts.sync = true;
  }
  if (FLAGS_rate_limit_auto_wal_flush) {
    write_opts.rate_limiter_priority = Env::IO_USER;
  }
  char value[100];
  int cf_idx = 0;
  Status s;
  for (auto cfh : column_families_) {
    for (int64_t k = 0; k != number_of_keys; ++k) {
      const std::string key = Key(k);

      constexpr uint32_t value_base = 0;
      const size_t sz = GenerateValue(value_base, value, sizeof(value));

      const Slice v(value, sz);

      shared->Put(cf_idx, k, value_base, true /* pending */);

      std::string ts;
      if (FLAGS_user_timestamp_size > 0) {
        ts = GetNowNanos();
      }

      if (FLAGS_use_merge) {
        if (!FLAGS_use_txn) {
          if (FLAGS_user_timestamp_size > 0) {
            s = db_->Merge(write_opts, cfh, key, ts, v);
          } else {
            s = db_->Merge(write_opts, cfh, key, v);
          }
        } else {
          Transaction* txn;
          s = NewTxn(write_opts, &txn);
          if (s.ok()) {
            s = txn->Merge(cfh, key, v);
            if (s.ok()) {
              s = CommitTxn(txn);
            }
          }
        }
      } else if (FLAGS_use_put_entity_one_in > 0) {
        s = db_->PutEntity(write_opts, cfh, key,
                           GenerateWideColumns(value_base, v));
      } else {
        if (!FLAGS_use_txn) {
          if (FLAGS_user_timestamp_size > 0) {
            s = db_->Put(write_opts, cfh, key, ts, v);
          } else {
            s = db_->Put(write_opts, cfh, key, v);
          }
        } else {
          Transaction* txn;
          s = NewTxn(write_opts, &txn);
          if (s.ok()) {
            s = txn->Put(cfh, key, v);
            if (s.ok()) {
              s = CommitTxn(txn);
            }
          }
        }
      }

      shared->Put(cf_idx, k, value_base, false /* pending */);
      if (!s.ok()) {
        break;
      }
    }
    if (!s.ok()) {
      break;
    }
    ++cf_idx;
  }
  if (s.ok()) {
    s = db_->Flush(FlushOptions(), column_families_);
  }
  if (s.ok()) {
    for (auto cf : column_families_) {
      delete cf;
    }
    column_families_.clear();
    delete db_;
    db_ = nullptr;
    txn_db_ = nullptr;

    db_preload_finished_.store(true);
    auto now = clock_->NowMicros();
    fprintf(stdout, "%s Reopening database in read-only\n",
            clock_->TimeToString(now / 1000000).c_str());
    // Reopen as read-only, can ignore all options related to updates
    Open(shared);
  } else {
    fprintf(stderr, "Failed to preload db");
    exit(1);
  }
}

Status StressTest::SetOptions(ThreadState* thread) {
  assert(FLAGS_set_options_one_in > 0);
  std::unordered_map<std::string, std::string> opts;
  std::string name =
      options_index_[thread->rand.Next() % options_index_.size()];
  int value_idx = thread->rand.Next() % options_table_[name].size();
  if (name == "level0_file_num_compaction_trigger" ||
      name == "level0_slowdown_writes_trigger" ||
      name == "level0_stop_writes_trigger") {
    opts["level0_file_num_compaction_trigger"] =
        options_table_["level0_file_num_compaction_trigger"][value_idx];
    opts["level0_slowdown_writes_trigger"] =
        options_table_["level0_slowdown_writes_trigger"][value_idx];
    opts["level0_stop_writes_trigger"] =
        options_table_["level0_stop_writes_trigger"][value_idx];
  } else {
    opts[name] = options_table_[name][value_idx];
  }

  int rand_cf_idx = thread->rand.Next() % FLAGS_column_families;
  auto cfh = column_families_[rand_cf_idx];
  return db_->SetOptions(cfh, opts);
}

void StressTest::ProcessRecoveredPreparedTxns(SharedState* shared) {
  assert(txn_db_);
  std::vector<Transaction*> recovered_prepared_trans;
  txn_db_->GetAllPreparedTransactions(&recovered_prepared_trans);
  for (Transaction* txn : recovered_prepared_trans) {
    ProcessRecoveredPreparedTxnsHelper(txn, shared);
    delete txn;
  }
  recovered_prepared_trans.clear();
  txn_db_->GetAllPreparedTransactions(&recovered_prepared_trans);
  assert(recovered_prepared_trans.size() == 0);
}

void StressTest::ProcessRecoveredPreparedTxnsHelper(Transaction* txn,
                                                    SharedState* shared) {
  thread_local Random rand(static_cast<uint32_t>(FLAGS_seed));
  for (size_t i = 0; i < column_families_.size(); ++i) {
    std::unique_ptr<WBWIIterator> wbwi_iter(
        txn->GetWriteBatch()->NewIterator(column_families_[i]));
    for (wbwi_iter->SeekToFirst(); wbwi_iter->Valid(); wbwi_iter->Next()) {
      uint64_t key_val;
      if (GetIntVal(wbwi_iter->Entry().key.ToString(), &key_val)) {
        shared->Put(static_cast<int>(i) /* cf_idx */, key_val,
                    0 /* value_base */, true /* pending */);
      }
    }
  }
  if (rand.OneIn(2)) {
    Status s = txn->Commit();
    assert(s.ok());
  } else {
    Status s = txn->Rollback();
    assert(s.ok());
  }
}

Status StressTest::NewTxn(WriteOptions& write_opts, Transaction** txn) {
  if (!FLAGS_use_txn) {
    return Status::InvalidArgument("NewTxn when FLAGS_use_txn is not set");
  }
  write_opts.disableWAL = FLAGS_disable_wal;
  static std::atomic<uint64_t> txn_id = {0};
  TransactionOptions txn_options;
  txn_options.use_only_the_last_commit_time_batch_for_recovery =
      FLAGS_use_only_the_last_commit_time_batch_for_recovery;
  txn_options.lock_timeout = 600000;  // 10 min
  txn_options.deadlock_detect = true;
  *txn = txn_db_->BeginTransaction(write_opts, txn_options);
  auto istr = std::to_string(txn_id.fetch_add(1));
  Status s = (*txn)->SetName("xid" + istr);
  return s;
}

Status StressTest::CommitTxn(Transaction* txn, ThreadState* thread) {
  if (!FLAGS_use_txn) {
    return Status::InvalidArgument("CommitTxn when FLAGS_use_txn is not set");
  }
  assert(txn_db_);
  Status s = txn->Prepare();
  std::shared_ptr<const Snapshot> timestamped_snapshot;
  if (s.ok()) {
    if (thread && FLAGS_create_timestamped_snapshot_one_in &&
        thread->rand.OneIn(FLAGS_create_timestamped_snapshot_one_in)) {
      uint64_t ts = db_stress_env->NowNanos();
      s = txn->CommitAndTryCreateSnapshot(/*notifier=*/nullptr, ts,
                                          &timestamped_snapshot);

      std::pair<Status, std::shared_ptr<const Snapshot>> res;
      if (thread->tid == 0) {
        uint64_t now = db_stress_env->NowNanos();
        res = txn_db_->CreateTimestampedSnapshot(now);
        if (res.first.ok()) {
          assert(res.second);
          assert(res.second->GetTimestamp() == now);
          if (timestamped_snapshot) {
            assert(res.second->GetTimestamp() >
                   timestamped_snapshot->GetTimestamp());
          }
        } else {
          assert(!res.second);
        }
      }
    } else {
      s = txn->Commit();
    }
  }
  if (thread && FLAGS_create_timestamped_snapshot_one_in > 0 &&
      thread->rand.OneInOpt(50000)) {
    uint64_t now = db_stress_env->NowNanos();
    constexpr uint64_t time_diff = static_cast<uint64_t>(1000) * 1000 * 1000;
    txn_db_->ReleaseTimestampedSnapshotsOlderThan(now - time_diff);
  }
  delete txn;
  return s;
}

Status StressTest::RollbackTxn(Transaction* txn) {
  if (!FLAGS_use_txn) {
    return Status::InvalidArgument(
        "RollbackTxn when FLAGS_use_txn is not"
        " set");
  }
  Status s = txn->Rollback();
  delete txn;
  return s;
}

void StressTest::OperateDb(ThreadState* thread) {
  ReadOptions read_opts(FLAGS_verify_checksum, true);
  read_opts.rate_limiter_priority =
      FLAGS_rate_limit_user_ops ? Env::IO_USER : Env::IO_TOTAL;
  read_opts.async_io = FLAGS_async_io;
  read_opts.adaptive_readahead = FLAGS_adaptive_readahead;
  read_opts.readahead_size = FLAGS_readahead_size;
  WriteOptions write_opts;
  if (FLAGS_rate_limit_auto_wal_flush) {
    write_opts.rate_limiter_priority = Env::IO_USER;
  }
  auto shared = thread->shared;
  char value[100];
  std::string from_db;
  if (FLAGS_sync) {
    write_opts.sync = true;
  }
  write_opts.disableWAL = FLAGS_disable_wal;
  write_opts.protection_bytes_per_key = FLAGS_batch_protection_bytes_per_key;
  const int prefix_bound = static_cast<int>(FLAGS_readpercent) +
                           static_cast<int>(FLAGS_prefixpercent);
  const int write_bound = prefix_bound + static_cast<int>(FLAGS_writepercent);
  const int del_bound = write_bound + static_cast<int>(FLAGS_delpercent);
  const int delrange_bound =
      del_bound + static_cast<int>(FLAGS_delrangepercent);
  const int iterate_bound =
      delrange_bound + static_cast<int>(FLAGS_iterpercent);

  const uint64_t ops_per_open = FLAGS_ops_per_thread / (FLAGS_reopen + 1);

#ifndef NDEBUG
  if (FLAGS_read_fault_one_in) {
    fault_fs_guard->SetThreadLocalReadErrorContext(thread->shared->GetSeed(),
                                                   FLAGS_read_fault_one_in);
  }
#endif  // NDEBUG
  if (FLAGS_write_fault_one_in) {
    IOStatus error_msg;
    if (FLAGS_injest_error_severity <= 1 || FLAGS_injest_error_severity > 2) {
      error_msg = IOStatus::IOError("Retryable IO Error");
      error_msg.SetRetryable(true);
    } else if (FLAGS_injest_error_severity == 2) {
      // Ingest the fatal error
      error_msg = IOStatus::IOError("Fatal IO Error");
      error_msg.SetDataLoss(true);
    }
    std::vector<FileType> types = {FileType::kTableFile,
                                   FileType::kDescriptorFile,
                                   FileType::kCurrentFile};
    fault_fs_guard->SetRandomWriteError(
        thread->shared->GetSeed(), FLAGS_write_fault_one_in, error_msg,
        /*inject_for_all_file_types=*/false, types);
  }
  thread->stats.Start();
  for (int open_cnt = 0; open_cnt <= FLAGS_reopen; ++open_cnt) {
    if (thread->shared->HasVerificationFailedYet() ||
        thread->shared->ShouldStopTest()) {
      break;
    }
    if (open_cnt != 0) {
      thread->stats.FinishedSingleOp();
      MutexLock l(thread->shared->GetMutex());
      while (!thread->snapshot_queue.empty()) {
        db_->ReleaseSnapshot(thread->snapshot_queue.front().second.snapshot);
        delete thread->snapshot_queue.front().second.key_vec;
        thread->snapshot_queue.pop();
      }
      thread->shared->IncVotedReopen();
      if (thread->shared->AllVotedReopen()) {
        thread->shared->GetStressTest()->Reopen(thread);
        thread->shared->GetCondVar()->SignalAll();
      } else {
        thread->shared->GetCondVar()->Wait();
      }
      // Commenting this out as we don't want to reset stats on each open.
      // thread->stats.Start();
    }

    for (uint64_t i = 0; i < ops_per_open; i++) {
      if (thread->shared->HasVerificationFailedYet()) {
        break;
      }

      // Change Options
      if (thread->rand.OneInOpt(FLAGS_set_options_one_in)) {
        SetOptions(thread);
      }

      if (thread->rand.OneInOpt(FLAGS_set_in_place_one_in)) {
        options_.inplace_update_support ^= options_.inplace_update_support;
      }

      if (thread->tid == 0 && FLAGS_verify_db_one_in > 0 &&
          thread->rand.OneIn(FLAGS_verify_db_one_in)) {
        ContinuouslyVerifyDb(thread);
        if (thread->shared->ShouldStopTest()) {
          break;
        }
      }

      MaybeClearOneColumnFamily(thread);

      if (thread->rand.OneInOpt(FLAGS_manual_wal_flush_one_in)) {
        bool sync = thread->rand.OneIn(2) ? true : false;
        Status s = db_->FlushWAL(sync);
        if (!s.ok() && !(sync && s.IsNotSupported())) {
          fprintf(stderr, "FlushWAL(sync=%s) failed: %s\n",
                  (sync ? "true" : "false"), s.ToString().c_str());
        }
      }

      if (thread->rand.OneInOpt(FLAGS_lock_wal_one_in)) {
        Status s = db_->LockWAL();
        if (!s.ok()) {
          fprintf(stderr, "LockWAL() failed: %s\n", s.ToString().c_str());
        } else {
          auto old_seqno = db_->GetLatestSequenceNumber();
          // Yield for a while
          do {
            std::this_thread::yield();
          } while (thread->rand.OneIn(2));
          // Latest seqno should not have changed
          auto new_seqno = db_->GetLatestSequenceNumber();
          if (old_seqno != new_seqno) {
            fprintf(
                stderr,
                "Failure: latest seqno changed from %u to %u with WAL locked\n",
                (unsigned)old_seqno, (unsigned)new_seqno);
          }
          s = db_->UnlockWAL();
          if (!s.ok()) {
            fprintf(stderr, "UnlockWAL() failed: %s\n", s.ToString().c_str());
          }
        }
      }

      if (thread->rand.OneInOpt(FLAGS_sync_wal_one_in)) {
        Status s = db_->SyncWAL();
        if (!s.ok() && !s.IsNotSupported()) {
          fprintf(stderr, "SyncWAL() failed: %s\n", s.ToString().c_str());
        }
      }

      int rand_column_family = thread->rand.Next() % FLAGS_column_families;
      ColumnFamilyHandle* column_family = column_families_[rand_column_family];

      if (thread->rand.OneInOpt(FLAGS_compact_files_one_in)) {
        TestCompactFiles(thread, column_family);
      }

      int64_t rand_key = GenerateOneKey(thread, i);
      std::string keystr = Key(rand_key);
      Slice key = keystr;

      if (thread->rand.OneInOpt(FLAGS_compact_range_one_in)) {
        TestCompactRange(thread, rand_key, key, column_family);
        if (thread->shared->HasVerificationFailedYet()) {
          break;
        }
      }

      std::vector<int> rand_column_families =
          GenerateColumnFamilies(FLAGS_column_families, rand_column_family);

      if (thread->rand.OneInOpt(FLAGS_flush_one_in)) {
        Status status = TestFlush(rand_column_families);
        if (!status.ok()) {
          fprintf(stdout, "Unable to perform Flush(): %s\n",
                  status.ToString().c_str());
        }
      }

      // Verify GetLiveFiles with a 1 in N chance.
      if (thread->rand.OneInOpt(FLAGS_get_live_files_one_in) &&
          !FLAGS_write_fault_one_in) {
        Status status = VerifyGetLiveFiles();
        if (!status.ok()) {
          VerificationAbort(shared, "VerifyGetLiveFiles status not OK", status);
        }
      }

      // Verify GetSortedWalFiles with a 1 in N chance.
      if (thread->rand.OneInOpt(FLAGS_get_sorted_wal_files_one_in)) {
        Status status = VerifyGetSortedWalFiles();
        if (!status.ok()) {
          VerificationAbort(shared, "VerifyGetSortedWalFiles status not OK",
                            status);
        }
      }

      // Verify GetCurrentWalFile with a 1 in N chance.
      if (thread->rand.OneInOpt(FLAGS_get_current_wal_file_one_in)) {
        Status status = VerifyGetCurrentWalFile();
        if (!status.ok()) {
          VerificationAbort(shared, "VerifyGetCurrentWalFile status not OK",
                            status);
        }
      }

      if (thread->rand.OneInOpt(FLAGS_pause_background_one_in)) {
        Status status = TestPauseBackground(thread);
        if (!status.ok()) {
          VerificationAbort(
              shared, "Pause/ContinueBackgroundWork status not OK", status);
        }
      }

      if (thread->rand.OneInOpt(FLAGS_verify_checksum_one_in)) {
        Status status = db_->VerifyChecksum();
        if (!status.ok()) {
          VerificationAbort(shared, "VerifyChecksum status not OK", status);
        }
      }

      if (thread->rand.OneInOpt(FLAGS_get_property_one_in)) {
        TestGetProperty(thread);
      }

      std::vector<int64_t> rand_keys = GenerateKeys(rand_key);

      if (thread->rand.OneInOpt(FLAGS_ingest_external_file_one_in)) {
        TestIngestExternalFile(thread, rand_column_families, rand_keys);
      }

      if (thread->rand.OneInOpt(FLAGS_backup_one_in)) {
        // Beyond a certain DB size threshold, this test becomes heavier than
        // it's worth.
        uint64_t total_size = 0;
        if (FLAGS_backup_max_size > 0) {
          std::vector<FileAttributes> files;
          db_stress_env->GetChildrenFileAttributes(FLAGS_db, &files);
          for (auto& file : files) {
            total_size += file.size_bytes;
          }
        }

        if (total_size <= FLAGS_backup_max_size) {
          Status s = TestBackupRestore(thread, rand_column_families, rand_keys);
          if (!s.ok()) {
            VerificationAbort(shared, "Backup/restore gave inconsistent state",
                              s);
          }
        }
      }

      if (thread->rand.OneInOpt(FLAGS_checkpoint_one_in)) {
        Status s = TestCheckpoint(thread, rand_column_families, rand_keys);
        if (!s.ok()) {
          VerificationAbort(shared, "Checkpoint gave inconsistent state", s);
        }
      }

      if (thread->rand.OneInOpt(FLAGS_approximate_size_one_in)) {
        Status s =
            TestApproximateSize(thread, i, rand_column_families, rand_keys);
        if (!s.ok()) {
          VerificationAbort(shared, "ApproximateSize Failed", s);
        }
      }
      if (thread->rand.OneInOpt(FLAGS_acquire_snapshot_one_in)) {
        TestAcquireSnapshot(thread, rand_column_family, keystr, i);
      }

      /*always*/ {
        Status s = MaybeReleaseSnapshots(thread, i);
        if (!s.ok()) {
          VerificationAbort(shared, "Snapshot gave inconsistent state", s);
        }
      }

      // Assign timestamps if necessary.
      std::string read_ts_str;
      Slice read_ts;
      if (FLAGS_user_timestamp_size > 0) {
        read_ts_str = GetNowNanos();
        read_ts = read_ts_str;
        read_opts.timestamp = &read_ts;
      }

      int prob_op = thread->rand.Uniform(100);
      // Reset this in case we pick something other than a read op. We don't
      // want to use a stale value when deciding at the beginning of the loop
      // whether to vote to reopen
      if (prob_op >= 0 && prob_op < static_cast<int>(FLAGS_readpercent)) {
        assert(0 <= prob_op);
        // OPERATION read
        if (FLAGS_use_multiget) {
          // Leave room for one more iteration of the loop with a single key
          // batch. This is to ensure that each thread does exactly the same
          // number of ops
          int multiget_batch_size = static_cast<int>(
              std::min(static_cast<uint64_t>(thread->rand.Uniform(64)),
                       FLAGS_ops_per_thread - i - 1));
          // If its the last iteration, ensure that multiget_batch_size is 1
          multiget_batch_size = std::max(multiget_batch_size, 1);
          rand_keys = GenerateNKeys(thread, multiget_batch_size, i);
          TestMultiGet(thread, read_opts, rand_column_families, rand_keys);
          i += multiget_batch_size - 1;
        } else {
          TestGet(thread, read_opts, rand_column_families, rand_keys);
        }
      } else if (prob_op < prefix_bound) {
        assert(static_cast<int>(FLAGS_readpercent) <= prob_op);
        // OPERATION prefix scan
        // keys are 8 bytes long, prefix size is FLAGS_prefix_size. There are
        // (8 - FLAGS_prefix_size) bytes besides the prefix. So there will
        // be 2 ^ ((8 - FLAGS_prefix_size) * 8) possible keys with the same
        // prefix
        TestPrefixScan(thread, read_opts, rand_column_families, rand_keys);
      } else if (prob_op < write_bound) {
        assert(prefix_bound <= prob_op);
        // OPERATION write
        TestPut(thread, write_opts, read_opts, rand_column_families, rand_keys,
                value);
      } else if (prob_op < del_bound) {
        assert(write_bound <= prob_op);
        // OPERATION delete
        TestDelete(thread, write_opts, rand_column_families, rand_keys);
      } else if (prob_op < delrange_bound) {
        assert(del_bound <= prob_op);
        // OPERATION delete range
        TestDeleteRange(thread, write_opts, rand_column_families, rand_keys);
      } else if (prob_op < iterate_bound) {
        assert(delrange_bound <= prob_op);
        // OPERATION iterate
        if (!FLAGS_skip_verifydb &&
            thread->rand.OneInOpt(
                FLAGS_verify_iterator_with_expected_state_one_in)) {
          TestIterateAgainstExpected(thread, read_opts, rand_column_families,
                                     rand_keys);
        } else {
          int num_seeks = static_cast<int>(std::min(
              std::max(static_cast<uint64_t>(thread->rand.Uniform(4)),
                       static_cast<uint64_t>(1)),
              std::max(static_cast<uint64_t>(FLAGS_ops_per_thread - i - 1),
                       static_cast<uint64_t>(1))));
          rand_keys = GenerateNKeys(thread, num_seeks, i);
          i += num_seeks - 1;
          TestIterate(thread, read_opts, rand_column_families, rand_keys);
        }
      } else {
        assert(iterate_bound <= prob_op);
        TestCustomOperations(thread, rand_column_families);
      }
      thread->stats.FinishedSingleOp();
    }
  }
  while (!thread->snapshot_queue.empty()) {
    db_->ReleaseSnapshot(thread->snapshot_queue.front().second.snapshot);
    delete thread->snapshot_queue.front().second.key_vec;
    thread->snapshot_queue.pop();
  }

  thread->stats.Stop();
}

// Generated a list of keys that close to boundaries of SST keys.
// If there isn't any SST file in the DB, return empty list.
std::vector<std::string> StressTest::GetWhiteBoxKeys(ThreadState* thread,
                                                     DB* db,
                                                     ColumnFamilyHandle* cfh,
                                                     size_t num_keys) {
  ColumnFamilyMetaData cfmd;
  db->GetColumnFamilyMetaData(cfh, &cfmd);
  std::vector<std::string> boundaries;
  for (const LevelMetaData& lmd : cfmd.levels) {
    for (const SstFileMetaData& sfmd : lmd.files) {
      // If FLAGS_user_timestamp_size > 0, then both smallestkey and largestkey
      // have timestamps.
      const auto& skey = sfmd.smallestkey;
      const auto& lkey = sfmd.largestkey;
      assert(skey.size() >= FLAGS_user_timestamp_size);
      assert(lkey.size() >= FLAGS_user_timestamp_size);
      boundaries.push_back(
          skey.substr(0, skey.size() - FLAGS_user_timestamp_size));
      boundaries.push_back(
          lkey.substr(0, lkey.size() - FLAGS_user_timestamp_size));
    }
  }
  if (boundaries.empty()) {
    return {};
  }

  std::vector<std::string> ret;
  for (size_t j = 0; j < num_keys; j++) {
    std::string k =
        boundaries[thread->rand.Uniform(static_cast<int>(boundaries.size()))];
    if (thread->rand.OneIn(3)) {
      // Reduce one byte from the string
      for (int i = static_cast<int>(k.length()) - 1; i >= 0; i--) {
        uint8_t cur = k[i];
        if (cur > 0) {
          k[i] = static_cast<char>(cur - 1);
          break;
        } else if (i > 0) {
          k[i] = 0xFFu;
        }
      }
    } else if (thread->rand.OneIn(2)) {
      // Add one byte to the string
      for (int i = static_cast<int>(k.length()) - 1; i >= 0; i--) {
        uint8_t cur = k[i];
        if (cur < 255) {
          k[i] = static_cast<char>(cur + 1);
          break;
        } else if (i > 0) {
          k[i] = 0x00;
        }
      }
    }
    ret.push_back(k);
  }
  return ret;
}

// Given a key K, this creates an iterator which scans to K and then
// does a random sequence of Next/Prev operations.
Status StressTest::TestIterate(ThreadState* thread,
                               const ReadOptions& read_opts,
                               const std::vector<int>& rand_column_families,
                               const std::vector<int64_t>& rand_keys) {
  assert(!rand_column_families.empty());
  assert(!rand_keys.empty());

  ManagedSnapshot snapshot_guard(db_);

  ReadOptions ro = read_opts;
  ro.snapshot = snapshot_guard.snapshot();

  std::string read_ts_str;
  Slice read_ts_slice;
  MaybeUseOlderTimestampForRangeScan(thread, read_ts_str, read_ts_slice, ro);

  bool expect_total_order = false;
  if (thread->rand.OneIn(16)) {
    // When prefix extractor is used, it's useful to cover total order seek.
    ro.total_order_seek = true;
    expect_total_order = true;
  } else if (thread->rand.OneIn(4)) {
    ro.total_order_seek = false;
    ro.auto_prefix_mode = true;
    expect_total_order = true;
  } else if (options_.prefix_extractor.get() == nullptr) {
    expect_total_order = true;
  }

  std::string upper_bound_str;
  Slice upper_bound;
  if (thread->rand.OneIn(16)) {
    // With a 1/16 chance, set an iterator upper bound.
    // Note: upper_bound can be smaller than the seek key.
    const int64_t rand_upper_key = GenerateOneKey(thread, FLAGS_ops_per_thread);
    upper_bound_str = Key(rand_upper_key);
    upper_bound = Slice(upper_bound_str);
    ro.iterate_upper_bound = &upper_bound;
  }
  std::string lower_bound_str;
  Slice lower_bound;
  if (thread->rand.OneIn(16)) {
    // With a 1/16 chance, enable iterator lower bound.
    // Note: lower_bound can be greater than the seek key.
    const int64_t rand_lower_key = GenerateOneKey(thread, FLAGS_ops_per_thread);
    lower_bound_str = Key(rand_lower_key);
    lower_bound = Slice(lower_bound_str);
    ro.iterate_lower_bound = &lower_bound;
  }

  ColumnFamilyHandle* const cfh = column_families_[rand_column_families[0]];
  assert(cfh);

  std::unique_ptr<Iterator> iter(db_->NewIterator(ro, cfh));

  std::vector<std::string> key_strs;
  if (thread->rand.OneIn(16)) {
    // Generate keys close to lower or upper bound of SST files.
    key_strs = GetWhiteBoxKeys(thread, db_, cfh, rand_keys.size());
  }
  if (key_strs.empty()) {
    // Use the random keys passed in.
    for (int64_t rkey : rand_keys) {
      key_strs.push_back(Key(rkey));
    }
  }

  std::string op_logs;
  constexpr size_t kOpLogsLimit = 10000;

  for (const std::string& key_str : key_strs) {
    if (op_logs.size() > kOpLogsLimit) {
      // Shouldn't take too much memory for the history log. Clear it.
      op_logs = "(cleared...)\n";
    }

    if (ro.iterate_upper_bound != nullptr && thread->rand.OneIn(2)) {
      // With a 1/2 chance, change the upper bound.
      // It is possible that it is changed before first use, but there is no
      // problem with that.
      const int64_t rand_upper_key =
          GenerateOneKey(thread, FLAGS_ops_per_thread);
      upper_bound_str = Key(rand_upper_key);
      upper_bound = Slice(upper_bound_str);
    }
    if (ro.iterate_lower_bound != nullptr && thread->rand.OneIn(4)) {
      // With a 1/4 chance, change the lower bound.
      // It is possible that it is changed before first use, but there is no
      // problem with that.
      const int64_t rand_lower_key =
          GenerateOneKey(thread, FLAGS_ops_per_thread);
      lower_bound_str = Key(rand_lower_key);
      lower_bound = Slice(lower_bound_str);
    }

    // Record some options to op_logs
    op_logs += "total_order_seek: ";
    op_logs += (ro.total_order_seek ? "1 " : "0 ");
    op_logs += "auto_prefix_mode: ";
    op_logs += (ro.auto_prefix_mode ? "1 " : "0 ");
    if (ro.iterate_upper_bound != nullptr) {
      op_logs += "ub: " + upper_bound.ToString(true) + " ";
    }
    if (ro.iterate_lower_bound != nullptr) {
      op_logs += "lb: " + lower_bound.ToString(true) + " ";
    }

    // Set up an iterator, perform the same operations without bounds and with
    // total order seek, and compare the results. This is to identify bugs
    // related to bounds, prefix extractor, or reseeking. Sometimes we are
    // comparing iterators with the same set-up, and it doesn't hurt to check
    // them to be equal.
    //
    // This `ReadOptions` is for validation purposes. Ignore
    // `FLAGS_rate_limit_user_ops` to avoid slowing any validation.
    ReadOptions cmp_ro;
    cmp_ro.timestamp = ro.timestamp;
    cmp_ro.iter_start_ts = ro.iter_start_ts;
    cmp_ro.snapshot = snapshot_guard.snapshot();
    cmp_ro.total_order_seek = true;

    ColumnFamilyHandle* const cmp_cfh =
        GetControlCfh(thread, rand_column_families[0]);
    assert(cmp_cfh);

    std::unique_ptr<Iterator> cmp_iter(db_->NewIterator(cmp_ro, cmp_cfh));

    bool diverged = false;

    Slice key(key_str);

    const bool support_seek_first_or_last = expect_total_order;

    LastIterateOp last_op;
    if (support_seek_first_or_last && thread->rand.OneIn(100)) {
      iter->SeekToFirst();
      cmp_iter->SeekToFirst();
      last_op = kLastOpSeekToFirst;
      op_logs += "STF ";
    } else if (support_seek_first_or_last && thread->rand.OneIn(100)) {
      iter->SeekToLast();
      cmp_iter->SeekToLast();
      last_op = kLastOpSeekToLast;
      op_logs += "STL ";
    } else if (thread->rand.OneIn(8)) {
      iter->SeekForPrev(key);
      cmp_iter->SeekForPrev(key);
      last_op = kLastOpSeekForPrev;
      op_logs += "SFP " + key.ToString(true) + " ";
    } else {
      iter->Seek(key);
      cmp_iter->Seek(key);
      last_op = kLastOpSeek;
      op_logs += "S " + key.ToString(true) + " ";
    }

    VerifyIterator(thread, cmp_cfh, ro, iter.get(), cmp_iter.get(), last_op,
                   key, op_logs, &diverged);

    const bool no_reverse =
        (FLAGS_memtablerep == "prefix_hash" && !expect_total_order);
    for (uint64_t i = 0; i < FLAGS_num_iterations && iter->Valid(); ++i) {
      if (no_reverse || thread->rand.OneIn(2)) {
        iter->Next();
        if (!diverged) {
          assert(cmp_iter->Valid());
          cmp_iter->Next();
        }
        op_logs += "N";
      } else {
        iter->Prev();
        if (!diverged) {
          assert(cmp_iter->Valid());
          cmp_iter->Prev();
        }
        op_logs += "P";
      }

      last_op = kLastOpNextOrPrev;

      VerifyIterator(thread, cmp_cfh, ro, iter.get(), cmp_iter.get(), last_op,
                     key, op_logs, &diverged);
    }

    thread->stats.AddIterations(1);

    op_logs += "; ";
  }

  return Status::OK();
}

// Test the return status of GetLiveFiles.
Status StressTest::VerifyGetLiveFiles() const {
  std::vector<std::string> live_file;
  uint64_t manifest_size = 0;
  return db_->GetLiveFiles(live_file, &manifest_size);
}

// Test the return status of GetSortedWalFiles.
Status StressTest::VerifyGetSortedWalFiles() const {
  VectorLogPtr log_ptr;
  return db_->GetSortedWalFiles(log_ptr);
}

// Test the return status of GetCurrentWalFile.
Status StressTest::VerifyGetCurrentWalFile() const {
  std::unique_ptr<LogFile> cur_wal_file;
  return db_->GetCurrentWalFile(&cur_wal_file);
}

// Compare the two iterator, iter and cmp_iter are in the same position,
// unless iter might be made invalidate or undefined because of
// upper or lower bounds, or prefix extractor.
// Will flag failure if the verification fails.
// diverged = true if the two iterator is already diverged.
// True if verification passed, false if not.
void StressTest::VerifyIterator(ThreadState* thread,
                                ColumnFamilyHandle* cmp_cfh,
                                const ReadOptions& ro, Iterator* iter,
                                Iterator* cmp_iter, LastIterateOp op,
                                const Slice& seek_key,
                                const std::string& op_logs, bool* diverged) {
  assert(diverged);

  if (*diverged) {
    return;
  }

  if (ro.iter_start_ts != nullptr) {
    assert(FLAGS_user_timestamp_size > 0);
    // We currently do not verify iterator when dumping history of internal
    // keys.
    *diverged = true;
    return;
  }

  if (op == kLastOpSeekToFirst && ro.iterate_lower_bound != nullptr) {
    // SeekToFirst() with lower bound is not well defined.
    *diverged = true;
    return;
  } else if (op == kLastOpSeekToLast && ro.iterate_upper_bound != nullptr) {
    // SeekToLast() with higher bound is not well defined.
    *diverged = true;
    return;
  } else if (op == kLastOpSeek && ro.iterate_lower_bound != nullptr &&
             (options_.comparator->CompareWithoutTimestamp(
                  *ro.iterate_lower_bound, /*a_has_ts=*/false, seek_key,
                  /*b_has_ts=*/false) >= 0 ||
              (ro.iterate_upper_bound != nullptr &&
               options_.comparator->CompareWithoutTimestamp(
                   *ro.iterate_lower_bound, /*a_has_ts=*/false,
                   *ro.iterate_upper_bound, /*b_has_ts*/ false) >= 0))) {
    // Lower bound behavior is not well defined if it is larger than
    // seek key or upper bound. Disable the check for now.
    *diverged = true;
    return;
  } else if (op == kLastOpSeekForPrev && ro.iterate_upper_bound != nullptr &&
             (options_.comparator->CompareWithoutTimestamp(
                  *ro.iterate_upper_bound, /*a_has_ts=*/false, seek_key,
                  /*b_has_ts=*/false) <= 0 ||
              (ro.iterate_lower_bound != nullptr &&
               options_.comparator->CompareWithoutTimestamp(
                   *ro.iterate_lower_bound, /*a_has_ts=*/false,
                   *ro.iterate_upper_bound, /*b_has_ts=*/false) >= 0))) {
    // Uppder bound behavior is not well defined if it is smaller than
    // seek key or lower bound. Disable the check for now.
    *diverged = true;
    return;
  }

  const SliceTransform* pe = (ro.total_order_seek || ro.auto_prefix_mode)
                                 ? nullptr
                                 : options_.prefix_extractor.get();
  const Comparator* cmp = options_.comparator;

  if (iter->Valid() && !cmp_iter->Valid()) {
    if (pe != nullptr) {
      if (!pe->InDomain(seek_key)) {
        // Prefix seek a non-in-domain key is undefined. Skip checking for
        // this scenario.
        *diverged = true;
        return;
      } else if (!pe->InDomain(iter->key())) {
        // out of range is iterator key is not in domain anymore.
        *diverged = true;
        return;
      } else if (pe->Transform(iter->key()) != pe->Transform(seek_key)) {
        *diverged = true;
        return;
      }
    }
    fprintf(stderr,
            "Control interator is invalid but iterator has key %s "
            "%s\n",
            iter->key().ToString(true).c_str(), op_logs.c_str());

    *diverged = true;
  } else if (cmp_iter->Valid()) {
    // Iterator is not valid. It can be legimate if it has already been
    // out of upper or lower bound, or filtered out by prefix iterator.
    const Slice& total_order_key = cmp_iter->key();

    if (pe != nullptr) {
      if (!pe->InDomain(seek_key)) {
        // Prefix seek a non-in-domain key is undefined. Skip checking for
        // this scenario.
        *diverged = true;
        return;
      }

      if (!pe->InDomain(total_order_key) ||
          pe->Transform(total_order_key) != pe->Transform(seek_key)) {
        // If the prefix is exhausted, the only thing needs to check
        // is the iterator isn't return a position in prefix.
        // Either way, checking can stop from here.
        *diverged = true;
        if (!iter->Valid() || !pe->InDomain(iter->key()) ||
            pe->Transform(iter->key()) != pe->Transform(seek_key)) {
          return;
        }
        fprintf(stderr,
                "Iterator stays in prefix but contol doesn't"
                " iterator key %s control iterator key %s %s\n",
                iter->key().ToString(true).c_str(),
                cmp_iter->key().ToString(true).c_str(), op_logs.c_str());
      }
    }
    // Check upper or lower bounds.
    if (!*diverged) {
      if ((iter->Valid() && iter->key() != cmp_iter->key()) ||
          (!iter->Valid() &&
           (ro.iterate_upper_bound == nullptr ||
            cmp->CompareWithoutTimestamp(total_order_key, /*a_has_ts=*/false,
                                         *ro.iterate_upper_bound,
                                         /*b_has_ts=*/false) < 0) &&
           (ro.iterate_lower_bound == nullptr ||
            cmp->CompareWithoutTimestamp(total_order_key, /*a_has_ts=*/false,
                                         *ro.iterate_lower_bound,
                                         /*b_has_ts=*/false) > 0))) {
        fprintf(stderr,
                "Iterator diverged from control iterator which"
                " has value %s %s\n",
                total_order_key.ToString(true).c_str(), op_logs.c_str());
        if (iter->Valid()) {
          fprintf(stderr, "iterator has value %s\n",
                  iter->key().ToString(true).c_str());
        } else {
          fprintf(stderr, "iterator is not valid\n");
        }
        *diverged = true;
      }
    }
  }

  if (!*diverged && iter->Valid()) {
    const WideColumns expected_columns =
        GenerateExpectedWideColumns(GetValueBase(iter->value()), iter->value());
    if (iter->columns() != expected_columns) {
      fprintf(stderr, "Value and columns inconsistent for iterator: %s\n",
              DebugString(iter->value(), iter->columns(), expected_columns)
                  .c_str());

      *diverged = true;
    }
  }

  if (*diverged) {
    fprintf(stderr, "Control CF %s\n", cmp_cfh->GetName().c_str());
    thread->stats.AddErrors(1);
    // Fail fast to preserve the DB state.
    thread->shared->SetVerificationFailure();
  }
}

Status StressTest::TestBackupRestore(
    ThreadState* thread, const std::vector<int>& rand_column_families,
    const std::vector<int64_t>& rand_keys) {
  std::vector<std::unique_ptr<MutexLock>> locks;
  if (ShouldAcquireMutexOnKey()) {
    for (int rand_column_family : rand_column_families) {
      // `rand_keys[0]` on each chosen CF will be verified.
      locks.emplace_back(new MutexLock(
          thread->shared->GetMutexForKey(rand_column_family, rand_keys[0])));
    }
  }

  const std::string backup_dir =
      FLAGS_db + "/.backup" + std::to_string(thread->tid);
  const std::string restore_dir =
      FLAGS_db + "/.restore" + std::to_string(thread->tid);
  BackupEngineOptions backup_opts(backup_dir);
  // For debugging, get info_log from live options
  backup_opts.info_log = db_->GetDBOptions().info_log.get();
  if (thread->rand.OneIn(10)) {
    backup_opts.share_table_files = false;
  } else {
    backup_opts.share_table_files = true;
    if (thread->rand.OneIn(5)) {
      backup_opts.share_files_with_checksum = false;
    } else {
      backup_opts.share_files_with_checksum = true;
      if (thread->rand.OneIn(2)) {
        // old
        backup_opts.share_files_with_checksum_naming =
            BackupEngineOptions::kLegacyCrc32cAndFileSize;
      } else {
        // new
        backup_opts.share_files_with_checksum_naming =
            BackupEngineOptions::kUseDbSessionId;
      }
      if (thread->rand.OneIn(2)) {
        backup_opts.share_files_with_checksum_naming =
            backup_opts.share_files_with_checksum_naming |
            BackupEngineOptions::kFlagIncludeFileSize;
      }
    }
  }
  if (thread->rand.OneIn(2)) {
    backup_opts.schema_version = 1;
  } else {
    backup_opts.schema_version = 2;
  }
  BackupEngine* backup_engine = nullptr;
  std::string from = "a backup/restore operation";
  Status s = BackupEngine::Open(db_stress_env, backup_opts, &backup_engine);
  if (!s.ok()) {
    from = "BackupEngine::Open";
  }
  if (s.ok()) {
    if (backup_opts.schema_version >= 2 && thread->rand.OneIn(2)) {
      TEST_BackupMetaSchemaOptions test_opts;
      test_opts.crc32c_checksums = thread->rand.OneIn(2) == 0;
      test_opts.file_sizes = thread->rand.OneIn(2) == 0;
      TEST_SetBackupMetaSchemaOptions(backup_engine, test_opts);
    }
    CreateBackupOptions create_opts;
    if (FLAGS_disable_wal) {
      // The verification can only work when latest value of `key` is backed up,
      // which requires flushing in case of WAL disabled.
      //
      // Note this triggers a flush with a key lock held. Meanwhile, operations
      // like flush/compaction may attempt to grab key locks like in
      // `DbStressCompactionFilter`. The philosophy around preventing deadlock
      // is the background operation key lock acquisition only tries but does
      // not wait for the lock. So here in the foreground it is OK to hold the
      // lock and wait on a background operation (flush).
      create_opts.flush_before_backup = true;
    }
    s = backup_engine->CreateNewBackup(create_opts, db_);
    if (!s.ok()) {
      from = "BackupEngine::CreateNewBackup";
    }
  }
  if (s.ok()) {
    delete backup_engine;
    backup_engine = nullptr;
    s = BackupEngine::Open(db_stress_env, backup_opts, &backup_engine);
    if (!s.ok()) {
      from = "BackupEngine::Open (again)";
    }
  }
  std::vector<BackupInfo> backup_info;
  // If inplace_not_restore, we verify the backup by opening it as a
  // read-only DB. If !inplace_not_restore, we restore it to a temporary
  // directory for verification.
  bool inplace_not_restore = thread->rand.OneIn(3);
  if (s.ok()) {
    backup_engine->GetBackupInfo(&backup_info,
                                 /*include_file_details*/ inplace_not_restore);
    if (backup_info.empty()) {
      s = Status::NotFound("no backups found");
      from = "BackupEngine::GetBackupInfo";
    }
  }
  if (s.ok() && thread->rand.OneIn(2)) {
    s = backup_engine->VerifyBackup(
        backup_info.front().backup_id,
        thread->rand.OneIn(2) /* verify_with_checksum */);
    if (!s.ok()) {
      from = "BackupEngine::VerifyBackup";
    }
  }
  const bool allow_persistent = thread->tid == 0;  // not too many
  bool from_latest = false;
  int count = static_cast<int>(backup_info.size());
  if (s.ok() && !inplace_not_restore) {
    if (count > 1) {
      s = backup_engine->RestoreDBFromBackup(
          RestoreOptions(), backup_info[thread->rand.Uniform(count)].backup_id,
          restore_dir /* db_dir */, restore_dir /* wal_dir */);
      if (!s.ok()) {
        from = "BackupEngine::RestoreDBFromBackup";
      }
    } else {
      from_latest = true;
      s = backup_engine->RestoreDBFromLatestBackup(RestoreOptions(),
                                                   restore_dir /* db_dir */,
                                                   restore_dir /* wal_dir */);
      if (!s.ok()) {
        from = "BackupEngine::RestoreDBFromLatestBackup";
      }
    }
  }
  if (s.ok() && !inplace_not_restore) {
    // Purge early if restoring, to ensure the restored directory doesn't
    // have some secret dependency on the backup directory.
    uint32_t to_keep = 0;
    if (allow_persistent) {
      // allow one thread to keep up to 2 backups
      to_keep = thread->rand.Uniform(3);
    }
    s = backup_engine->PurgeOldBackups(to_keep);
    if (!s.ok()) {
      from = "BackupEngine::PurgeOldBackups";
    }
  }
  DB* restored_db = nullptr;
  std::vector<ColumnFamilyHandle*> restored_cf_handles;
  // Not yet implemented: opening restored BlobDB or TransactionDB
  if (s.ok() && !FLAGS_use_txn && !FLAGS_use_blob_db) {
    Options restore_options(options_);
    restore_options.best_efforts_recovery = false;
    restore_options.listeners.clear();
    // Avoid dangling/shared file descriptors, for reliable destroy
    restore_options.sst_file_manager = nullptr;
    std::vector<ColumnFamilyDescriptor> cf_descriptors;
    // TODO(ajkr): `column_family_names_` is not safe to access here when
    // `clear_column_family_one_in != 0`. But we can't easily switch to
    // `ListColumnFamilies` to get names because it won't necessarily give
    // the same order as `column_family_names_`.
    assert(FLAGS_clear_column_family_one_in == 0);
    for (auto name : column_family_names_) {
      cf_descriptors.emplace_back(name, ColumnFamilyOptions(restore_options));
    }
    if (inplace_not_restore) {
      BackupInfo& info = backup_info[thread->rand.Uniform(count)];
      restore_options.env = info.env_for_open.get();
      s = DB::OpenForReadOnly(DBOptions(restore_options), info.name_for_open,
                              cf_descriptors, &restored_cf_handles,
                              &restored_db);
      if (!s.ok()) {
        from = "DB::OpenForReadOnly in backup/restore";
      }
    } else {
      s = DB::Open(DBOptions(restore_options), restore_dir, cf_descriptors,
                   &restored_cf_handles, &restored_db);
      if (!s.ok()) {
        from = "DB::Open in backup/restore";
      }
    }
  }
  // Note the column families chosen by `rand_column_families` cannot be
  // dropped while the locks for `rand_keys` are held. So we should not have
  // to worry about accessing those column families throughout this function.
  //
  // For simplicity, currently only verifies existence/non-existence of a
  // single key
  for (size_t i = 0; restored_db && s.ok() && i < rand_column_families.size();
       ++i) {
    std::string key_str = Key(rand_keys[0]);
    Slice key = key_str;
    std::string restored_value;
    // This `ReadOptions` is for validation purposes. Ignore
    // `FLAGS_rate_limit_user_ops` to avoid slowing any validation.
    ReadOptions read_opts;
    std::string ts_str;
    Slice ts;
    if (FLAGS_user_timestamp_size > 0) {
      ts_str = GetNowNanos();
      ts = ts_str;
      read_opts.timestamp = &ts;
    }
    Status get_status = restored_db->Get(
        read_opts, restored_cf_handles[rand_column_families[i]], key,
        &restored_value);
    bool exists = thread->shared->Exists(rand_column_families[i], rand_keys[0]);
    if (get_status.ok()) {
      if (!exists && from_latest && ShouldAcquireMutexOnKey()) {
        std::ostringstream oss;
        oss << "0x" << key.ToString(true)
            << " exists in restore but not in original db";
        s = Status::Corruption(oss.str());
      }
    } else if (get_status.IsNotFound()) {
      if (exists && from_latest && ShouldAcquireMutexOnKey()) {
        std::ostringstream oss;
        oss << "0x" << key.ToString(true)
            << " exists in original db but not in restore";
        s = Status::Corruption(oss.str());
      }
    } else {
      s = get_status;
      if (!s.ok()) {
        from = "DB::Get in backup/restore";
      }
    }
  }
  if (restored_db != nullptr) {
    for (auto* cf_handle : restored_cf_handles) {
      restored_db->DestroyColumnFamilyHandle(cf_handle);
    }
    delete restored_db;
    restored_db = nullptr;
  }
  if (s.ok() && inplace_not_restore) {
    // Purge late if inplace open read-only
    uint32_t to_keep = 0;
    if (allow_persistent) {
      // allow one thread to keep up to 2 backups
      to_keep = thread->rand.Uniform(3);
    }
    s = backup_engine->PurgeOldBackups(to_keep);
    if (!s.ok()) {
      from = "BackupEngine::PurgeOldBackups";
    }
  }
  if (backup_engine != nullptr) {
    delete backup_engine;
    backup_engine = nullptr;
  }
  if (s.ok()) {
    // Preserve directories on failure, or allowed persistent backup
    if (!allow_persistent) {
      s = DestroyDir(db_stress_env, backup_dir);
      if (!s.ok()) {
        from = "Destroy backup dir";
      }
    }
  }
  if (s.ok()) {
    s = DestroyDir(db_stress_env, restore_dir);
    if (!s.ok()) {
      from = "Destroy restore dir";
    }
  }
  if (!s.ok()) {
    fprintf(stderr, "Failure in %s with: %s\n", from.c_str(),
            s.ToString().c_str());
  }
  return s;
}

Status StressTest::TestApproximateSize(
    ThreadState* thread, uint64_t iteration,
    const std::vector<int>& rand_column_families,
    const std::vector<int64_t>& rand_keys) {
  // rand_keys likely only has one key. Just use the first one.
  assert(!rand_keys.empty());
  assert(!rand_column_families.empty());
  int64_t key1 = rand_keys[0];
  int64_t key2;
  if (thread->rand.OneIn(2)) {
    // Two totally random keys. This tends to cover large ranges.
    key2 = GenerateOneKey(thread, iteration);
    if (key2 < key1) {
      std::swap(key1, key2);
    }
  } else {
    // Unless users pass a very large FLAGS_max_key, it we should not worry
    // about overflow. It is for testing, so we skip the overflow checking
    // for simplicity.
    key2 = key1 + static_cast<int64_t>(thread->rand.Uniform(1000));
  }
  std::string key1_str = Key(key1);
  std::string key2_str = Key(key2);
  Range range{Slice(key1_str), Slice(key2_str)};
  SizeApproximationOptions sao;
  sao.include_memtables = thread->rand.OneIn(2);
  if (sao.include_memtables) {
    sao.include_files = thread->rand.OneIn(2);
  }
  if (thread->rand.OneIn(2)) {
    if (thread->rand.OneIn(2)) {
      sao.files_size_error_margin = 0.0;
    } else {
      sao.files_size_error_margin =
          static_cast<double>(thread->rand.Uniform(3));
    }
  }
  uint64_t result;
  return db_->GetApproximateSizes(
      sao, column_families_[rand_column_families[0]], &range, 1, &result);
}

Status StressTest::TestCheckpoint(ThreadState* thread,
                                  const std::vector<int>& rand_column_families,
                                  const std::vector<int64_t>& rand_keys) {
  std::vector<std::unique_ptr<MutexLock>> locks;
  if (ShouldAcquireMutexOnKey()) {
    for (int rand_column_family : rand_column_families) {
      // `rand_keys[0]` on each chosen CF will be verified.
      locks.emplace_back(new MutexLock(
          thread->shared->GetMutexForKey(rand_column_family, rand_keys[0])));
    }
  }

  std::string checkpoint_dir =
      FLAGS_db + "/.checkpoint" + std::to_string(thread->tid);
  Options tmp_opts(options_);
  tmp_opts.listeners.clear();
  tmp_opts.env = db_stress_env;

  DestroyDB(checkpoint_dir, tmp_opts);

  if (db_stress_env->FileExists(checkpoint_dir).ok()) {
    // If the directory might still exist, try to delete the files one by one.
    // Likely a trash file is still there.
    Status my_s = DestroyDir(db_stress_env, checkpoint_dir);
    if (!my_s.ok()) {
      fprintf(stderr, "Fail to destory directory before checkpoint: %s",
              my_s.ToString().c_str());
    }
  }

  Checkpoint* checkpoint = nullptr;
  Status s = Checkpoint::Create(db_, &checkpoint);
  if (s.ok()) {
    s = checkpoint->CreateCheckpoint(checkpoint_dir);
    if (!s.ok()) {
      fprintf(stderr, "Fail to create checkpoint to %s\n",
              checkpoint_dir.c_str());
      std::vector<std::string> files;
      Status my_s = db_stress_env->GetChildren(checkpoint_dir, &files);
      if (my_s.ok()) {
        for (const auto& f : files) {
          fprintf(stderr, " %s\n", f.c_str());
        }
      } else {
        fprintf(stderr, "Fail to get files under the directory to %s\n",
                my_s.ToString().c_str());
      }
    }
  }
  delete checkpoint;
  checkpoint = nullptr;
  std::vector<ColumnFamilyHandle*> cf_handles;
  DB* checkpoint_db = nullptr;
  if (s.ok()) {
    Options options(options_);
    options.best_efforts_recovery = false;
    options.listeners.clear();
    // Avoid race condition in trash handling after delete checkpoint_db
    options.sst_file_manager.reset();
    std::vector<ColumnFamilyDescriptor> cf_descs;
    // TODO(ajkr): `column_family_names_` is not safe to access here when
    // `clear_column_family_one_in != 0`. But we can't easily switch to
    // `ListColumnFamilies` to get names because it won't necessarily give
    // the same order as `column_family_names_`.
    assert(FLAGS_clear_column_family_one_in == 0);
    if (FLAGS_clear_column_family_one_in == 0) {
      for (const auto& name : column_family_names_) {
        cf_descs.emplace_back(name, ColumnFamilyOptions(options));
      }
      s = DB::OpenForReadOnly(DBOptions(options), checkpoint_dir, cf_descs,
                              &cf_handles, &checkpoint_db);
    }
  }
  if (checkpoint_db != nullptr) {
    // Note the column families chosen by `rand_column_families` cannot be
    // dropped while the locks for `rand_keys` are held. So we should not have
    // to worry about accessing those column families throughout this function.
    for (size_t i = 0; s.ok() && i < rand_column_families.size(); ++i) {
      std::string key_str = Key(rand_keys[0]);
      Slice key = key_str;
      std::string ts_str;
      Slice ts;
      ReadOptions read_opts;
      if (FLAGS_user_timestamp_size > 0) {
        ts_str = GetNowNanos();
        ts = ts_str;
        read_opts.timestamp = &ts;
      }
      std::string value;
      Status get_status = checkpoint_db->Get(
          read_opts, cf_handles[rand_column_families[i]], key, &value);
      bool exists =
          thread->shared->Exists(rand_column_families[i], rand_keys[0]);
      if (get_status.ok()) {
        if (!exists && ShouldAcquireMutexOnKey()) {
          std::ostringstream oss;
          oss << "0x" << key.ToString(true) << " exists in checkpoint "
              << checkpoint_dir << " but not in original db";
          s = Status::Corruption(oss.str());
        }
      } else if (get_status.IsNotFound()) {
        if (exists && ShouldAcquireMutexOnKey()) {
          std::ostringstream oss;
          oss << "0x" << key.ToString(true)
              << " exists in original db but not in checkpoint "
              << checkpoint_dir;
          s = Status::Corruption(oss.str());
        }
      } else {
        s = get_status;
      }
    }
    for (auto cfh : cf_handles) {
      delete cfh;
    }
    cf_handles.clear();
    delete checkpoint_db;
    checkpoint_db = nullptr;
  }

  if (!s.ok()) {
    fprintf(stderr, "A checkpoint operation failed with: %s\n",
            s.ToString().c_str());
  } else {
    DestroyDB(checkpoint_dir, tmp_opts);
  }
  return s;
}

void StressTest::TestGetProperty(ThreadState* thread) const {
  std::unordered_set<std::string> levelPropertyNames = {
      DB::Properties::kAggregatedTablePropertiesAtLevel,
      DB::Properties::kCompressionRatioAtLevelPrefix,
      DB::Properties::kNumFilesAtLevelPrefix,
  };
  std::unordered_set<std::string> unknownPropertyNames = {
      DB::Properties::kEstimateOldestKeyTime,
      DB::Properties::kOptionsStatistics,
      DB::Properties::
          kLiveSstFilesSizeAtTemperature,  // similar to levelPropertyNames, it
                                           // requires a number suffix
  };
  unknownPropertyNames.insert(levelPropertyNames.begin(),
                              levelPropertyNames.end());

  std::unordered_set<std::string> blobCachePropertyNames = {
      DB::Properties::kBlobCacheCapacity,
      DB::Properties::kBlobCacheUsage,
      DB::Properties::kBlobCachePinnedUsage,
  };
  if (db_->GetOptions().blob_cache == nullptr) {
    unknownPropertyNames.insert(blobCachePropertyNames.begin(),
                                blobCachePropertyNames.end());
  }

  std::string prop;
  for (const auto& ppt_name_and_info : InternalStats::ppt_name_to_info) {
    bool res = db_->GetProperty(ppt_name_and_info.first, &prop);
    if (unknownPropertyNames.find(ppt_name_and_info.first) ==
        unknownPropertyNames.end()) {
      if (!res) {
        fprintf(stderr, "Failed to get DB property: %s\n",
                ppt_name_and_info.first.c_str());
        thread->shared->SetVerificationFailure();
      }
      if (ppt_name_and_info.second.handle_int != nullptr) {
        uint64_t prop_int;
        if (!db_->GetIntProperty(ppt_name_and_info.first, &prop_int)) {
          fprintf(stderr, "Failed to get Int property: %s\n",
                  ppt_name_and_info.first.c_str());
          thread->shared->SetVerificationFailure();
        }
      }
      if (ppt_name_and_info.second.handle_map != nullptr) {
        std::map<std::string, std::string> prop_map;
        if (!db_->GetMapProperty(ppt_name_and_info.first, &prop_map)) {
          fprintf(stderr, "Failed to get Map property: %s\n",
                  ppt_name_and_info.first.c_str());
          thread->shared->SetVerificationFailure();
        }
      }
    }
  }

  ROCKSDB_NAMESPACE::ColumnFamilyMetaData cf_meta_data;
  db_->GetColumnFamilyMetaData(&cf_meta_data);
  int level_size = static_cast<int>(cf_meta_data.levels.size());
  for (int level = 0; level < level_size; level++) {
    for (const auto& ppt_name : levelPropertyNames) {
      bool res = db_->GetProperty(ppt_name + std::to_string(level), &prop);
      if (!res) {
        fprintf(stderr, "Failed to get DB property: %s\n",
                (ppt_name + std::to_string(level)).c_str());
        thread->shared->SetVerificationFailure();
      }
    }
  }

  // Test for an invalid property name
  if (thread->rand.OneIn(100)) {
    if (db_->GetProperty("rocksdb.invalid_property_name", &prop)) {
      fprintf(stderr, "Failed to return false for invalid property name\n");
      thread->shared->SetVerificationFailure();
    }
  }
}

void StressTest::TestCompactFiles(ThreadState* thread,
                                  ColumnFamilyHandle* column_family) {
  ROCKSDB_NAMESPACE::ColumnFamilyMetaData cf_meta_data;
  db_->GetColumnFamilyMetaData(column_family, &cf_meta_data);

  if (cf_meta_data.levels.empty()) {
    return;
  }

  // Randomly compact up to three consecutive files from a level
  const int kMaxRetry = 3;
  for (int attempt = 0; attempt < kMaxRetry; ++attempt) {
    size_t random_level =
        thread->rand.Uniform(static_cast<int>(cf_meta_data.levels.size()));

    const auto& files = cf_meta_data.levels[random_level].files;
    if (files.size() > 0) {
      size_t random_file_index =
          thread->rand.Uniform(static_cast<int>(files.size()));
      if (files[random_file_index].being_compacted) {
        // Retry as the selected file is currently being compacted
        continue;
      }

      std::vector<std::string> input_files;
      input_files.push_back(files[random_file_index].name);
      if (random_file_index > 0 &&
          !files[random_file_index - 1].being_compacted) {
        input_files.push_back(files[random_file_index - 1].name);
      }
      if (random_file_index + 1 < files.size() &&
          !files[random_file_index + 1].being_compacted) {
        input_files.push_back(files[random_file_index + 1].name);
      }

      size_t output_level =
          std::min(random_level + 1, cf_meta_data.levels.size() - 1);
      auto s = db_->CompactFiles(CompactionOptions(), column_family,
                                 input_files, static_cast<int>(output_level));
      if (!s.ok()) {
        fprintf(stdout, "Unable to perform CompactFiles(): %s\n",
                s.ToString().c_str());
        thread->stats.AddNumCompactFilesFailed(1);
      } else {
        thread->stats.AddNumCompactFilesSucceed(1);
      }
      break;
    }
  }
}

Status StressTest::TestFlush(const std::vector<int>& rand_column_families) {
  FlushOptions flush_opts;
  if (FLAGS_atomic_flush) {
    return db_->Flush(flush_opts, column_families_);
  }
  std::vector<ColumnFamilyHandle*> cfhs;
  std::for_each(rand_column_families.begin(), rand_column_families.end(),
                [this, &cfhs](int k) { cfhs.push_back(column_families_[k]); });
  return db_->Flush(flush_opts, cfhs);
}

Status StressTest::TestPauseBackground(ThreadState* thread) {
  Status status = db_->PauseBackgroundWork();
  if (!status.ok()) {
    return status;
  }
  // To avoid stalling/deadlocking ourself in this thread, just
  // sleep here during pause and let other threads do db operations.
  // Sleep up to ~16 seconds (2**24 microseconds), but very skewed
  // toward short pause. (1 chance in 25 of pausing >= 1s;
  // 1 chance in 625 of pausing full 16s.)
  int pwr2_micros =
      std::min(thread->rand.Uniform(25), thread->rand.Uniform(25));
  clock_->SleepForMicroseconds(1 << pwr2_micros);
  return db_->ContinueBackgroundWork();
}

void StressTest::TestAcquireSnapshot(ThreadState* thread,
                                     int rand_column_family,
                                     const std::string& keystr, uint64_t i) {
  Slice key = keystr;
  ColumnFamilyHandle* column_family = column_families_[rand_column_family];
  // This `ReadOptions` is for validation purposes. Ignore
  // `FLAGS_rate_limit_user_ops` to avoid slowing any validation.
  ReadOptions ropt;
  auto db_impl = static_cast_with_check<DBImpl>(db_->GetRootDB());
  const bool ww_snapshot = thread->rand.OneIn(10);
  const Snapshot* snapshot =
      ww_snapshot ? db_impl->GetSnapshotForWriteConflictBoundary()
                  : db_->GetSnapshot();
  ropt.snapshot = snapshot;

  // Ideally, we want snapshot taking and timestamp generation to be atomic
  // here, so that the snapshot corresponds to the timestamp. However, it is
  // not possible with current GetSnapshot() API.
  std::string ts_str;
  Slice ts;
  if (FLAGS_user_timestamp_size > 0) {
    ts_str = GetNowNanos();
    ts = ts_str;
    ropt.timestamp = &ts;
  }

  std::string value_at;
  // When taking a snapshot, we also read a key from that snapshot. We
  // will later read the same key before releasing the snapshot and
  // verify that the results are the same.
  auto status_at = db_->Get(ropt, column_family, key, &value_at);
  std::vector<bool>* key_vec = nullptr;

  if (FLAGS_compare_full_db_state_snapshot && (thread->tid == 0)) {
    key_vec = new std::vector<bool>(FLAGS_max_key);
    // When `prefix_extractor` is set, seeking to beginning and scanning
    // across prefixes are only supported with `total_order_seek` set.
    ropt.total_order_seek = true;
    std::unique_ptr<Iterator> iterator(db_->NewIterator(ropt));
    for (iterator->SeekToFirst(); iterator->Valid(); iterator->Next()) {
      uint64_t key_val;
      if (GetIntVal(iterator->key().ToString(), &key_val)) {
        (*key_vec)[key_val] = true;
      }
    }
  }

  ThreadState::SnapshotState snap_state = {snapshot,
                                           rand_column_family,
                                           column_family->GetName(),
                                           keystr,
                                           status_at,
                                           value_at,
                                           key_vec,
                                           ts_str};
  uint64_t hold_for = FLAGS_snapshot_hold_ops;
  if (FLAGS_long_running_snapshots) {
    // Hold 10% of snapshots for 10x more
    if (thread->rand.OneIn(10)) {
      assert(hold_for < std::numeric_limits<uint64_t>::max() / 10);
      hold_for *= 10;
      // Hold 1% of snapshots for 100x more
      if (thread->rand.OneIn(10)) {
        assert(hold_for < std::numeric_limits<uint64_t>::max() / 10);
        hold_for *= 10;
      }
    }
  }
  uint64_t release_at = std::min(FLAGS_ops_per_thread - 1, i + hold_for);
  thread->snapshot_queue.emplace(release_at, snap_state);
}

Status StressTest::MaybeReleaseSnapshots(ThreadState* thread, uint64_t i) {
  while (!thread->snapshot_queue.empty() &&
         i >= thread->snapshot_queue.front().first) {
    auto snap_state = thread->snapshot_queue.front().second;
    assert(snap_state.snapshot);
    // Note: this is unsafe as the cf might be dropped concurrently. But
    // it is ok since unclean cf drop is cunnrently not supported by write
    // prepared transactions.
    Status s = AssertSame(db_, column_families_[snap_state.cf_at], snap_state);
    db_->ReleaseSnapshot(snap_state.snapshot);
    delete snap_state.key_vec;
    thread->snapshot_queue.pop();
    if (!s.ok()) {
      return s;
    }
  }
  return Status::OK();
}

void StressTest::TestCompactRange(ThreadState* thread, int64_t rand_key,
                                  const Slice& start_key,
                                  ColumnFamilyHandle* column_family) {
  int64_t end_key_num;
  if (std::numeric_limits<int64_t>::max() - rand_key <
      FLAGS_compact_range_width) {
    end_key_num = std::numeric_limits<int64_t>::max();
  } else {
    end_key_num = FLAGS_compact_range_width + rand_key;
  }
  std::string end_key_buf = Key(end_key_num);
  Slice end_key(end_key_buf);

  CompactRangeOptions cro;
  cro.exclusive_manual_compaction = static_cast<bool>(thread->rand.Next() % 2);
  cro.change_level = static_cast<bool>(thread->rand.Next() % 2);
  std::vector<BottommostLevelCompaction> bottom_level_styles = {
      BottommostLevelCompaction::kSkip,
      BottommostLevelCompaction::kIfHaveCompactionFilter,
      BottommostLevelCompaction::kForce,
      BottommostLevelCompaction::kForceOptimized};
  cro.bottommost_level_compaction =
      bottom_level_styles[thread->rand.Next() %
                          static_cast<uint32_t>(bottom_level_styles.size())];
  cro.allow_write_stall = static_cast<bool>(thread->rand.Next() % 2);
  cro.max_subcompactions = static_cast<uint32_t>(thread->rand.Next() % 4);
  std::vector<BlobGarbageCollectionPolicy> blob_gc_policies = {
      BlobGarbageCollectionPolicy::kForce,
      BlobGarbageCollectionPolicy::kDisable,
      BlobGarbageCollectionPolicy::kUseDefault};
  cro.blob_garbage_collection_policy =
      blob_gc_policies[thread->rand.Next() %
                       static_cast<uint32_t>(blob_gc_policies.size())];
  cro.blob_garbage_collection_age_cutoff =
      static_cast<double>(thread->rand.Next() % 100) / 100.0;

  const Snapshot* pre_snapshot = nullptr;
  uint32_t pre_hash = 0;
  if (thread->rand.OneIn(2)) {
    // Do some validation by declaring a snapshot and compare the data before
    // and after the compaction
    pre_snapshot = db_->GetSnapshot();
    pre_hash =
        GetRangeHash(thread, pre_snapshot, column_family, start_key, end_key);
  }

  Status status = db_->CompactRange(cro, column_family, &start_key, &end_key);

  if (!status.ok()) {
    fprintf(stdout, "Unable to perform CompactRange(): %s\n",
            status.ToString().c_str());
  }

  if (pre_snapshot != nullptr) {
    uint32_t post_hash =
        GetRangeHash(thread, pre_snapshot, column_family, start_key, end_key);
    if (pre_hash != post_hash) {
      fprintf(stderr,
              "Data hash different before and after compact range "
              "start_key %s end_key %s\n",
              start_key.ToString(true).c_str(), end_key.ToString(true).c_str());
      thread->stats.AddErrors(1);
      // Fail fast to preserve the DB state.
      thread->shared->SetVerificationFailure();
    }
    db_->ReleaseSnapshot(pre_snapshot);
  }
}

uint32_t StressTest::GetRangeHash(ThreadState* thread, const Snapshot* snapshot,
                                  ColumnFamilyHandle* column_family,
                                  const Slice& start_key,
                                  const Slice& end_key) {
  // This `ReadOptions` is for validation purposes. Ignore
  // `FLAGS_rate_limit_user_ops` to avoid slowing any validation.
  ReadOptions ro;
  ro.snapshot = snapshot;
  ro.total_order_seek = true;
  std::string ts_str;
  Slice ts;
  if (FLAGS_user_timestamp_size > 0) {
    ts_str = GetNowNanos();
    ts = ts_str;
    ro.timestamp = &ts;
  }

  std::unique_ptr<Iterator> it(db_->NewIterator(ro, column_family));

  constexpr char kCrcCalculatorSepearator = ';';

  uint32_t crc = 0;

  for (it->Seek(start_key);
       it->Valid() && options_.comparator->Compare(it->key(), end_key) <= 0;
       it->Next()) {
    crc = crc32c::Extend(crc, it->key().data(), it->key().size());
    crc = crc32c::Extend(crc, &kCrcCalculatorSepearator, sizeof(char));
    crc = crc32c::Extend(crc, it->value().data(), it->value().size());
    crc = crc32c::Extend(crc, &kCrcCalculatorSepearator, sizeof(char));

    for (const auto& column : it->columns()) {
      crc = crc32c::Extend(crc, column.name().data(), column.name().size());
      crc = crc32c::Extend(crc, &kCrcCalculatorSepearator, sizeof(char));
      crc = crc32c::Extend(crc, column.value().data(), column.value().size());
      crc = crc32c::Extend(crc, &kCrcCalculatorSepearator, sizeof(char));
    }
  }

  if (!it->status().ok()) {
    fprintf(stderr, "Iterator non-OK when calculating range CRC: %s\n",
            it->status().ToString().c_str());
    thread->stats.AddErrors(1);
    // Fail fast to preserve the DB state.
    thread->shared->SetVerificationFailure();
  }

  return crc;
}

void StressTest::PrintEnv() const {
  fprintf(stdout, "RocksDB version           : %d.%d\n", kMajorVersion,
          kMinorVersion);
  fprintf(stdout, "Format version            : %d\n", FLAGS_format_version);
  fprintf(stdout, "TransactionDB             : %s\n",
          FLAGS_use_txn ? "true" : "false");

  if (FLAGS_use_txn) {
    fprintf(stdout, "Two write queues:         : %s\n",
            FLAGS_two_write_queues ? "true" : "false");
    fprintf(stdout, "Write policy              : %d\n",
            static_cast<int>(FLAGS_txn_write_policy));
    if (static_cast<uint64_t>(TxnDBWritePolicy::WRITE_PREPARED) ==
            FLAGS_txn_write_policy ||
        static_cast<uint64_t>(TxnDBWritePolicy::WRITE_UNPREPARED) ==
            FLAGS_txn_write_policy) {
      fprintf(stdout, "Snapshot cache bits       : %d\n",
              static_cast<int>(FLAGS_wp_snapshot_cache_bits));
      fprintf(stdout, "Commit cache bits         : %d\n",
              static_cast<int>(FLAGS_wp_commit_cache_bits));
    }
    fprintf(stdout, "last cwb for recovery    : %s\n",
            FLAGS_use_only_the_last_commit_time_batch_for_recovery ? "true"
                                                                   : "false");
  }

  fprintf(stdout, "Stacked BlobDB            : %s\n",
          FLAGS_use_blob_db ? "true" : "false");
  fprintf(stdout, "Read only mode            : %s\n",
          FLAGS_read_only ? "true" : "false");
  fprintf(stdout, "Atomic flush              : %s\n",
          FLAGS_atomic_flush ? "true" : "false");
  fprintf(stdout, "Manual WAL flush          : %s\n",
          FLAGS_manual_wal_flush_one_in > 0 ? "true" : "false");
  fprintf(stdout, "Column families           : %d\n", FLAGS_column_families);
  if (!FLAGS_test_batches_snapshots) {
    fprintf(stdout, "Clear CFs one in          : %d\n",
            FLAGS_clear_column_family_one_in);
  }
  fprintf(stdout, "Number of threads         : %d\n", FLAGS_threads);
  fprintf(stdout, "Ops per thread            : %lu\n",
          (unsigned long)FLAGS_ops_per_thread);
  std::string ttl_state("unused");
  if (FLAGS_ttl > 0) {
    ttl_state = std::to_string(FLAGS_ttl);
  }
  fprintf(stdout, "Time to live(sec)         : %s\n", ttl_state.c_str());
  fprintf(stdout, "Read percentage           : %d%%\n", FLAGS_readpercent);
  fprintf(stdout, "Prefix percentage         : %d%%\n", FLAGS_prefixpercent);
  fprintf(stdout, "Write percentage          : %d%%\n", FLAGS_writepercent);
  fprintf(stdout, "Delete percentage         : %d%%\n", FLAGS_delpercent);
  fprintf(stdout, "Delete range percentage   : %d%%\n", FLAGS_delrangepercent);
  fprintf(stdout, "No overwrite percentage   : %d%%\n",
          FLAGS_nooverwritepercent);
  fprintf(stdout, "Iterate percentage        : %d%%\n", FLAGS_iterpercent);
  fprintf(stdout, "Custom ops percentage     : %d%%\n", FLAGS_customopspercent);
  fprintf(stdout, "DB-write-buffer-size      : %" PRIu64 "\n",
          FLAGS_db_write_buffer_size);
  fprintf(stdout, "Write-buffer-size         : %d\n", FLAGS_write_buffer_size);
  fprintf(stdout, "Iterations                : %lu\n",
          (unsigned long)FLAGS_num_iterations);
  fprintf(stdout, "Max key                   : %lu\n",
          (unsigned long)FLAGS_max_key);
  fprintf(stdout, "Ratio #ops/#keys          : %f\n",
          (1.0 * FLAGS_ops_per_thread * FLAGS_threads) / FLAGS_max_key);
  fprintf(stdout, "Num times DB reopens      : %d\n", FLAGS_reopen);
  fprintf(stdout, "Batches/snapshots         : %d\n",
          FLAGS_test_batches_snapshots);
  fprintf(stdout, "Do update in place        : %d\n", FLAGS_in_place_update);
  fprintf(stdout, "Num keys per lock         : %d\n",
          1 << FLAGS_log2_keys_per_lock);
  std::string compression = CompressionTypeToString(compression_type_e);
  fprintf(stdout, "Compression               : %s\n", compression.c_str());
  std::string bottommost_compression =
      CompressionTypeToString(bottommost_compression_type_e);
  fprintf(stdout, "Bottommost Compression    : %s\n",
          bottommost_compression.c_str());
  std::string checksum = ChecksumTypeToString(checksum_type_e);
  fprintf(stdout, "Checksum type             : %s\n", checksum.c_str());
  fprintf(stdout, "File checksum impl        : %s\n",
          FLAGS_file_checksum_impl.c_str());
  fprintf(stdout, "Bloom bits / key          : %s\n",
          FormatDoubleParam(FLAGS_bloom_bits).c_str());
  fprintf(stdout, "Max subcompactions        : %" PRIu64 "\n",
          FLAGS_subcompactions);
  fprintf(stdout, "Use MultiGet              : %s\n",
          FLAGS_use_multiget ? "true" : "false");

  const char* memtablerep = "";
  switch (FLAGS_rep_factory) {
    case kSkipList:
      memtablerep = "skip_list";
      break;
    case kHashSkipList:
      memtablerep = "prefix_hash";
      break;
    case kVectorRep:
      memtablerep = "vector";
      break;
  }

  fprintf(stdout, "Memtablerep               : %s\n", memtablerep);

#ifndef NDEBUG
  KillPoint* kp = KillPoint::GetInstance();
  fprintf(stdout, "Test kill odd             : %d\n", kp->rocksdb_kill_odds);
  if (!kp->rocksdb_kill_exclude_prefixes.empty()) {
    fprintf(stdout, "Skipping kill points prefixes:\n");
    for (auto& p : kp->rocksdb_kill_exclude_prefixes) {
      fprintf(stdout, "  %s\n", p.c_str());
    }
  }
#endif
  fprintf(stdout, "Periodic Compaction Secs  : %" PRIu64 "\n",
          FLAGS_periodic_compaction_seconds);
  fprintf(stdout, "Compaction TTL            : %" PRIu64 "\n",
          FLAGS_compaction_ttl);
  const char* compaction_pri = "";
  switch (FLAGS_compaction_pri) {
    case kByCompensatedSize:
      compaction_pri = "kByCompensatedSize";
      break;
    case kOldestLargestSeqFirst:
      compaction_pri = "kOldestLargestSeqFirst";
      break;
    case kOldestSmallestSeqFirst:
      compaction_pri = "kOldestSmallestSeqFirst";
      break;
    case kMinOverlappingRatio:
      compaction_pri = "kMinOverlappingRatio";
      break;
    case kRoundRobin:
      compaction_pri = "kRoundRobin";
      break;
  }
  fprintf(stdout, "Compaction Pri            : %s\n", compaction_pri);
  fprintf(stdout, "Background Purge          : %d\n",
          static_cast<int>(FLAGS_avoid_unnecessary_blocking_io));
  fprintf(stdout, "Write DB ID to manifest   : %d\n",
          static_cast<int>(FLAGS_write_dbid_to_manifest));
  fprintf(stdout, "Max Write Batch Group Size: %" PRIu64 "\n",
          FLAGS_max_write_batch_group_size_bytes);
  fprintf(stdout, "Use dynamic level         : %d\n",
          static_cast<int>(FLAGS_level_compaction_dynamic_level_bytes));
  fprintf(stdout, "Read fault one in         : %d\n", FLAGS_read_fault_one_in);
  fprintf(stdout, "Write fault one in        : %d\n", FLAGS_write_fault_one_in);
  fprintf(stdout, "Open metadata write fault one in:\n");
  fprintf(stdout, "                            %d\n",
          FLAGS_open_metadata_write_fault_one_in);
  fprintf(stdout, "Sync fault injection      : %d\n",
          FLAGS_sync_fault_injection);
  fprintf(stdout, "Best efforts recovery     : %d\n",
          static_cast<int>(FLAGS_best_efforts_recovery));
  fprintf(stdout, "Fail if OPTIONS file error: %d\n",
          static_cast<int>(FLAGS_fail_if_options_file_error));
  fprintf(stdout, "User timestamp size bytes : %d\n",
          static_cast<int>(FLAGS_user_timestamp_size));
  fprintf(stdout, "WAL compression           : %s\n",
          FLAGS_wal_compression.c_str());
  fprintf(stdout, "Try verify sst unique id  : %d\n",
          static_cast<int>(FLAGS_verify_sst_unique_id_in_manifest));

  fprintf(stdout, "------------------------------------------------\n");
}

void StressTest::Open(SharedState* shared) {
  assert(db_ == nullptr);
  assert(txn_db_ == nullptr);
  if (!InitializeOptionsFromFile(options_)) {
    InitializeOptionsFromFlags(cache_, filter_policy_, options_);
  }
  InitializeOptionsGeneral(cache_, filter_policy_, options_);

  if (FLAGS_prefix_size == 0 && FLAGS_rep_factory == kHashSkipList) {
    fprintf(stderr,
            "prefeix_size cannot be zero if memtablerep == prefix_hash\n");
    exit(1);
  }
  if (FLAGS_prefix_size != 0 && FLAGS_rep_factory != kHashSkipList) {
    fprintf(stderr,
            "WARNING: prefix_size is non-zero but "
            "memtablerep != prefix_hash\n");
  }

  if ((options_.enable_blob_files || options_.enable_blob_garbage_collection ||
       FLAGS_allow_setting_blob_options_dynamically) &&
      FLAGS_best_efforts_recovery) {
    fprintf(stderr,
            "Integrated BlobDB is currently incompatible with best-effort "
            "recovery\n");
    exit(1);
  }

  fprintf(stdout,
          "Integrated BlobDB: blob files enabled %d, min blob size %" PRIu64
          ", blob file size %" PRIu64
          ", blob compression type %s, blob GC enabled %d, cutoff %f, force "
          "threshold %f, blob compaction readahead size %" PRIu64
          ", blob file starting level %d\n",
          options_.enable_blob_files, options_.min_blob_size,
          options_.blob_file_size,
          CompressionTypeToString(options_.blob_compression_type).c_str(),
          options_.enable_blob_garbage_collection,
          options_.blob_garbage_collection_age_cutoff,
          options_.blob_garbage_collection_force_threshold,
          options_.blob_compaction_readahead_size,
          options_.blob_file_starting_level);

  if (FLAGS_use_blob_cache) {
    fprintf(stdout,
            "Integrated BlobDB: blob cache enabled"
            ", block and blob caches shared: %d",
            FLAGS_use_shared_block_and_blob_cache);
    if (!FLAGS_use_shared_block_and_blob_cache) {
      fprintf(stdout,
              ", blob cache size %" PRIu64 ", blob cache num shard bits: %d",
              FLAGS_blob_cache_size, FLAGS_blob_cache_numshardbits);
    }
    fprintf(stdout, ", blob cache prepopulated: %d\n",
            FLAGS_prepopulate_blob_cache);
  } else {
    fprintf(stdout, "Integrated BlobDB: blob cache disabled\n");
  }

  fprintf(stdout, "DB path: [%s]\n", FLAGS_db.c_str());

  Status s;

  if (FLAGS_ttl == -1) {
    std::vector<std::string> existing_column_families;
    s = DB::ListColumnFamilies(DBOptions(options_), FLAGS_db,
                               &existing_column_families);  // ignore errors
    if (!s.ok()) {
      // DB doesn't exist
      assert(existing_column_families.empty());
      assert(column_family_names_.empty());
      column_family_names_.push_back(kDefaultColumnFamilyName);
    } else if (column_family_names_.empty()) {
      // this is the first call to the function Open()
      column_family_names_ = existing_column_families;
    } else {
      // this is a reopen. just assert that existing column_family_names are
      // equivalent to what we remember
      auto sorted_cfn = column_family_names_;
      std::sort(sorted_cfn.begin(), sorted_cfn.end());
      std::sort(existing_column_families.begin(),
                existing_column_families.end());
      if (sorted_cfn != existing_column_families) {
        fprintf(stderr, "Expected column families differ from the existing:\n");
        fprintf(stderr, "Expected: {");
        for (auto cf : sorted_cfn) {
          fprintf(stderr, "%s ", cf.c_str());
        }
        fprintf(stderr, "}\n");
        fprintf(stderr, "Existing: {");
        for (auto cf : existing_column_families) {
          fprintf(stderr, "%s ", cf.c_str());
        }
        fprintf(stderr, "}\n");
      }
      assert(sorted_cfn == existing_column_families);
    }
    std::vector<ColumnFamilyDescriptor> cf_descriptors;
    for (auto name : column_family_names_) {
      if (name != kDefaultColumnFamilyName) {
        new_column_family_name_ =
            std::max(new_column_family_name_.load(), std::stoi(name) + 1);
      }
      cf_descriptors.emplace_back(name, ColumnFamilyOptions(options_));
    }
    while (cf_descriptors.size() < (size_t)FLAGS_column_families) {
      std::string name = std::to_string(new_column_family_name_.load());
      new_column_family_name_++;
      cf_descriptors.emplace_back(name, ColumnFamilyOptions(options_));
      column_family_names_.push_back(name);
    }

    options_.listeners.clear();
    options_.listeners.emplace_back(new DbStressListener(
        FLAGS_db, options_.db_paths, cf_descriptors, db_stress_listener_env));
    RegisterAdditionalListeners();

    if (!FLAGS_use_txn) {
      // Determine whether we need to ingest file metadata write failures
      // during DB reopen. If it does, enable it.
      // Only ingest metadata error if it is reopening, as initial open
      // failure doesn't need to be handled.
      // TODO cover transaction DB is not covered in this fault test too.
      bool ingest_meta_error = false;
      bool ingest_write_error = false;
      bool ingest_read_error = false;
      if ((FLAGS_open_metadata_write_fault_one_in ||
           FLAGS_open_write_fault_one_in || FLAGS_open_read_fault_one_in) &&
          fault_fs_guard
              ->FileExists(FLAGS_db + "/CURRENT", IOOptions(), nullptr)
              .ok()) {
        if (!FLAGS_sync) {
          // When DB Stress is not sync mode, we expect all WAL writes to
          // WAL is durable. Buffering unsynced writes will cause false
          // positive in crash tests. Before we figure out a way to
          // solve it, skip WAL from failure injection.
          fault_fs_guard->SetSkipDirectWritableTypes({kWalFile});
        }
        ingest_meta_error = FLAGS_open_metadata_write_fault_one_in;
        ingest_write_error = FLAGS_open_write_fault_one_in;
        ingest_read_error = FLAGS_open_read_fault_one_in;
        if (ingest_meta_error) {
          fault_fs_guard->EnableMetadataWriteErrorInjection();
          fault_fs_guard->SetRandomMetadataWriteError(
              FLAGS_open_metadata_write_fault_one_in);
        }
        if (ingest_write_error) {
          fault_fs_guard->SetFilesystemDirectWritable(false);
          fault_fs_guard->EnableWriteErrorInjection();
          fault_fs_guard->SetRandomWriteError(
              static_cast<uint32_t>(FLAGS_seed), FLAGS_open_write_fault_one_in,
              IOStatus::IOError("Injected Open Error"),
              /*inject_for_all_file_types=*/true, /*types=*/{});
        }
        if (ingest_read_error) {
          fault_fs_guard->SetRandomReadError(FLAGS_open_read_fault_one_in);
        }
      }
      while (true) {
        // StackableDB-based BlobDB
        if (FLAGS_use_blob_db) {
          blob_db::BlobDBOptions blob_db_options;
          blob_db_options.min_blob_size = FLAGS_blob_db_min_blob_size;
          blob_db_options.bytes_per_sync = FLAGS_blob_db_bytes_per_sync;
          blob_db_options.blob_file_size = FLAGS_blob_db_file_size;
          blob_db_options.enable_garbage_collection = FLAGS_blob_db_enable_gc;
          blob_db_options.garbage_collection_cutoff = FLAGS_blob_db_gc_cutoff;

          blob_db::BlobDB* blob_db = nullptr;
          s = blob_db::BlobDB::Open(options_, blob_db_options, FLAGS_db,
                                    cf_descriptors, &column_families_,
                                    &blob_db);
          if (s.ok()) {
            db_ = blob_db;
          }
        } else
        {
          if (db_preload_finished_.load() && FLAGS_read_only) {
            s = DB::OpenForReadOnly(DBOptions(options_), FLAGS_db,
                                    cf_descriptors, &column_families_, &db_);
          } else {
            s = DB::Open(DBOptions(options_), FLAGS_db, cf_descriptors,
                         &column_families_, &db_);
          }
        }

        if (ingest_meta_error || ingest_write_error || ingest_read_error) {
          fault_fs_guard->SetFilesystemDirectWritable(true);
          fault_fs_guard->DisableMetadataWriteErrorInjection();
          fault_fs_guard->DisableWriteErrorInjection();
          fault_fs_guard->SetSkipDirectWritableTypes({});
          fault_fs_guard->SetRandomReadError(0);
          if (s.ok()) {
            // Ingested errors might happen in background compactions. We
            // wait for all compactions to finish to make sure DB is in
            // clean state before executing queries.
            s = static_cast_with_check<DBImpl>(db_->GetRootDB())
                    ->WaitForCompact(true /* wait_unscheduled */);
            if (!s.ok()) {
              for (auto cf : column_families_) {
                delete cf;
              }
              column_families_.clear();
              delete db_;
              db_ = nullptr;
            }
          }
          if (!s.ok()) {
            // After failure to opening a DB due to IO error, retry should
            // successfully open the DB with correct data if no IO error shows
            // up.
            ingest_meta_error = false;
            ingest_write_error = false;
            ingest_read_error = false;

            Random rand(static_cast<uint32_t>(FLAGS_seed));
            if (rand.OneIn(2)) {
              fault_fs_guard->DeleteFilesCreatedAfterLastDirSync(IOOptions(),
                                                                 nullptr);
            }
            if (rand.OneIn(3)) {
              fault_fs_guard->DropUnsyncedFileData();
            } else if (rand.OneIn(2)) {
              fault_fs_guard->DropRandomUnsyncedFileData(&rand);
            }
            continue;
          }
        }
        break;
      }
    } else {
      TransactionDBOptions txn_db_options;
      assert(FLAGS_txn_write_policy <= TxnDBWritePolicy::WRITE_UNPREPARED);
      txn_db_options.write_policy =
          static_cast<TxnDBWritePolicy>(FLAGS_txn_write_policy);
      if (FLAGS_unordered_write) {
        assert(txn_db_options.write_policy == TxnDBWritePolicy::WRITE_PREPARED);
        options_.unordered_write = true;
        options_.two_write_queues = true;
        txn_db_options.skip_concurrency_control = true;
      } else {
        options_.two_write_queues = FLAGS_two_write_queues;
      }
      txn_db_options.wp_snapshot_cache_bits =
          static_cast<size_t>(FLAGS_wp_snapshot_cache_bits);
      txn_db_options.wp_commit_cache_bits =
          static_cast<size_t>(FLAGS_wp_commit_cache_bits);
      PrepareTxnDbOptions(shared, txn_db_options);
      s = TransactionDB::Open(options_, txn_db_options, FLAGS_db,
                              cf_descriptors, &column_families_, &txn_db_);
      if (!s.ok()) {
        fprintf(stderr, "Error in opening the TransactionDB [%s]\n",
                s.ToString().c_str());
        fflush(stderr);
      }
      assert(s.ok());

      // Do not swap the order of the following.
      {
        db_ = txn_db_;
        db_aptr_.store(txn_db_, std::memory_order_release);
      }
    }
    if (!s.ok()) {
      fprintf(stderr, "Error in opening the DB [%s]\n", s.ToString().c_str());
      fflush(stderr);
    }
    assert(s.ok());
    assert(column_families_.size() ==
           static_cast<size_t>(FLAGS_column_families));

    // Secondary instance does not support write-prepared/write-unprepared
    // transactions, thus just disable secondary instance if we use
    // transaction.
    if (s.ok() && FLAGS_test_secondary && !FLAGS_use_txn) {
      Options tmp_opts;
      // TODO(yanqin) support max_open_files != -1 for secondary instance.
      tmp_opts.max_open_files = -1;
      tmp_opts.env = db_stress_env;
      const std::string& secondary_path = FLAGS_secondaries_base;
      s = DB::OpenAsSecondary(tmp_opts, FLAGS_db, secondary_path,
                              cf_descriptors, &cmp_cfhs_, &cmp_db_);
      assert(s.ok());
      assert(cmp_cfhs_.size() == static_cast<size_t>(FLAGS_column_families));
    }
  } else {
    DBWithTTL* db_with_ttl;
    s = DBWithTTL::Open(options_, FLAGS_db, &db_with_ttl, FLAGS_ttl);
    db_ = db_with_ttl;
  }

  if (FLAGS_preserve_unverified_changes) {
    // Up until now, no live file should have become obsolete due to these
    // options. After `DisableFileDeletions()` we can reenable auto compactions
    // since, even if live files become obsolete, they won't be deleted.
    assert(options_.avoid_flush_during_recovery);
    assert(options_.disable_auto_compactions);
    if (s.ok()) {
      s = db_->DisableFileDeletions();
    }
    if (s.ok()) {
      s = db_->EnableAutoCompaction(column_families_);
    }
  }

  if (!s.ok()) {
    fprintf(stderr, "open error: %s\n", s.ToString().c_str());
    exit(1);
  }
}

void StressTest::Reopen(ThreadState* thread) {
  // BG jobs in WritePrepared must be canceled first because i) they can access
  // the db via a callbac ii) they hold on to a snapshot and the upcoming
  // ::Close would complain about it.
  const bool write_prepared = FLAGS_use_txn && FLAGS_txn_write_policy != 0;
  bool bg_canceled __attribute__((unused)) = false;
  if (write_prepared || thread->rand.OneIn(2)) {
    const bool wait =
        write_prepared || static_cast<bool>(thread->rand.OneIn(2));
    CancelAllBackgroundWork(db_, wait);
    bg_canceled = wait;
  }
  assert(!write_prepared || bg_canceled);

  for (auto cf : column_families_) {
    delete cf;
  }
  column_families_.clear();

  if (thread->rand.OneIn(2)) {
    Status s = db_->Close();
    if (!s.ok()) {
      fprintf(stderr, "Non-ok close status: %s\n", s.ToString().c_str());
      fflush(stderr);
    }
    assert(s.ok());
  }
  assert(txn_db_ == nullptr || db_ == txn_db_);
  delete db_;
  db_ = nullptr;
  txn_db_ = nullptr;

  num_times_reopened_++;
  auto now = clock_->NowMicros();
  fprintf(stdout, "%s Reopening database for the %dth time\n",
          clock_->TimeToString(now / 1000000).c_str(), num_times_reopened_);
  Open(thread->shared);

  if ((FLAGS_sync_fault_injection || FLAGS_disable_wal ||
       FLAGS_manual_wal_flush_one_in > 0) &&
      IsStateTracked()) {
    Status s = thread->shared->SaveAtAndAfter(db_);
    if (!s.ok()) {
      fprintf(stderr, "Error enabling history tracing: %s\n",
              s.ToString().c_str());
      exit(1);
    }
  }
}

bool StressTest::MaybeUseOlderTimestampForPointLookup(ThreadState* thread,
                                                      std::string& ts_str,
                                                      Slice& ts_slice,
                                                      ReadOptions& read_opts) {
  if (FLAGS_user_timestamp_size == 0) {
    return false;
  }

  assert(thread);
  if (!thread->rand.OneInOpt(3)) {
    return false;
  }

  const SharedState* const shared = thread->shared;
  assert(shared);
  const uint64_t start_ts = shared->GetStartTimestamp();

  uint64_t now = db_stress_env->NowNanos();

  assert(now > start_ts);
  uint64_t time_diff = now - start_ts;
  uint64_t ts = start_ts + (thread->rand.Next64() % time_diff);
  ts_str.clear();
  PutFixed64(&ts_str, ts);
  ts_slice = ts_str;
  read_opts.timestamp = &ts_slice;
  return true;
}

void StressTest::MaybeUseOlderTimestampForRangeScan(ThreadState* thread,
                                                    std::string& ts_str,
                                                    Slice& ts_slice,
                                                    ReadOptions& read_opts) {
  if (FLAGS_user_timestamp_size == 0) {
    return;
  }

  assert(thread);
  if (!thread->rand.OneInOpt(3)) {
    return;
  }

  const Slice* const saved_ts = read_opts.timestamp;
  assert(saved_ts != nullptr);

  const SharedState* const shared = thread->shared;
  assert(shared);
  const uint64_t start_ts = shared->GetStartTimestamp();

  uint64_t now = db_stress_env->NowNanos();

  assert(now > start_ts);
  uint64_t time_diff = now - start_ts;
  uint64_t ts = start_ts + (thread->rand.Next64() % time_diff);
  ts_str.clear();
  PutFixed64(&ts_str, ts);
  ts_slice = ts_str;
  read_opts.timestamp = &ts_slice;

  // TODO (yanqin): support Merge with iter_start_ts
  if (!thread->rand.OneInOpt(3) || FLAGS_use_merge || FLAGS_use_full_merge_v1) {
    return;
  }

  ts_str.clear();
  PutFixed64(&ts_str, start_ts);
  ts_slice = ts_str;
  read_opts.iter_start_ts = &ts_slice;
  read_opts.timestamp = saved_ts;
}

void CheckAndSetOptionsForUserTimestamp(Options& options) {
  assert(FLAGS_user_timestamp_size > 0);
  const Comparator* const cmp = test::BytewiseComparatorWithU64TsWrapper();
  assert(cmp);
  if (FLAGS_user_timestamp_size != cmp->timestamp_size()) {
    fprintf(stderr,
            "Only -user_timestamp_size=%d is supported in stress test.\n",
            static_cast<int>(cmp->timestamp_size()));
    exit(1);
  }
  if (FLAGS_use_txn) {
    fprintf(stderr, "TransactionDB does not support timestamp yet.\n");
    exit(1);
  }
  if (FLAGS_test_cf_consistency || FLAGS_test_batches_snapshots) {
    fprintf(stderr,
            "Due to per-key ts-seq ordering constraint, only the (default) "
            "non-batched test is supported with timestamp.\n");
    exit(1);
  }
  if (FLAGS_ingest_external_file_one_in > 0) {
    fprintf(stderr, "Bulk loading may not support timestamp yet.\n");
    exit(1);
  }
  options.comparator = cmp;
}

bool InitializeOptionsFromFile(Options& options) {
  DBOptions db_options;
  ConfigOptions config_options;
  config_options.ignore_unknown_options = false;
  config_options.input_strings_escaped = true;
  config_options.env = db_stress_env;
  std::vector<ColumnFamilyDescriptor> cf_descriptors;
  if (!FLAGS_options_file.empty()) {
    Status s = LoadOptionsFromFile(config_options, FLAGS_options_file,
                                   &db_options, &cf_descriptors);
    if (!s.ok()) {
      fprintf(stderr, "Unable to load options file %s --- %s\n",
              FLAGS_options_file.c_str(), s.ToString().c_str());
      exit(1);
    }
    db_options.env = new CompositeEnvWrapper(db_stress_env);
    options = Options(db_options, cf_descriptors[0].options);
    return true;
  }
  return false;
}

void InitializeOptionsFromFlags(
    const std::shared_ptr<Cache>& cache,
    const std::shared_ptr<const FilterPolicy>& filter_policy,
    Options& options) {
  BlockBasedTableOptions block_based_options;
  block_based_options.block_cache = cache;
  block_based_options.cache_index_and_filter_blocks =
      FLAGS_cache_index_and_filter_blocks;
  block_based_options.metadata_cache_options.top_level_index_pinning =
      static_cast<PinningTier>(FLAGS_top_level_index_pinning);
  block_based_options.metadata_cache_options.partition_pinning =
      static_cast<PinningTier>(FLAGS_partition_pinning);
  block_based_options.metadata_cache_options.unpartitioned_pinning =
      static_cast<PinningTier>(FLAGS_unpartitioned_pinning);
  block_based_options.checksum = checksum_type_e;
  block_based_options.block_size = FLAGS_block_size;
  block_based_options.cache_usage_options.options_overrides.insert(
      {CacheEntryRole::kCompressionDictionaryBuildingBuffer,
       {/*.charged = */ FLAGS_charge_compression_dictionary_building_buffer
            ? CacheEntryRoleOptions::Decision::kEnabled
            : CacheEntryRoleOptions::Decision::kDisabled}});
  block_based_options.cache_usage_options.options_overrides.insert(
      {CacheEntryRole::kFilterConstruction,
       {/*.charged = */ FLAGS_charge_filter_construction
            ? CacheEntryRoleOptions::Decision::kEnabled
            : CacheEntryRoleOptions::Decision::kDisabled}});
  block_based_options.cache_usage_options.options_overrides.insert(
      {CacheEntryRole::kBlockBasedTableReader,
       {/*.charged = */ FLAGS_charge_table_reader
            ? CacheEntryRoleOptions::Decision::kEnabled
            : CacheEntryRoleOptions::Decision::kDisabled}});
  block_based_options.cache_usage_options.options_overrides.insert(
      {CacheEntryRole::kFileMetadata,
       {/*.charged = */ FLAGS_charge_file_metadata
            ? CacheEntryRoleOptions::Decision::kEnabled
            : CacheEntryRoleOptions::Decision::kDisabled}});
  block_based_options.cache_usage_options.options_overrides.insert(
      {CacheEntryRole::kBlobCache,
       {/*.charged = */ FLAGS_charge_blob_cache
            ? CacheEntryRoleOptions::Decision::kEnabled
            : CacheEntryRoleOptions::Decision::kDisabled}});
  block_based_options.format_version =
      static_cast<uint32_t>(FLAGS_format_version);
  block_based_options.index_block_restart_interval =
      static_cast<int32_t>(FLAGS_index_block_restart_interval);
  block_based_options.filter_policy = filter_policy;
  block_based_options.partition_filters = FLAGS_partition_filters;
  block_based_options.optimize_filters_for_memory =
      FLAGS_optimize_filters_for_memory;
  block_based_options.detect_filter_construct_corruption =
      FLAGS_detect_filter_construct_corruption;
  block_based_options.index_type =
      static_cast<BlockBasedTableOptions::IndexType>(FLAGS_index_type);
  block_based_options.data_block_index_type =
      static_cast<BlockBasedTableOptions::DataBlockIndexType>(
          FLAGS_data_block_index_type);
  block_based_options.prepopulate_block_cache =
      static_cast<BlockBasedTableOptions::PrepopulateBlockCache>(
          FLAGS_prepopulate_block_cache);
  block_based_options.initial_auto_readahead_size =
      FLAGS_initial_auto_readahead_size;
  block_based_options.max_auto_readahead_size = FLAGS_max_auto_readahead_size;
  block_based_options.num_file_reads_for_auto_readahead =
      FLAGS_num_file_reads_for_auto_readahead;
  options.table_factory.reset(NewBlockBasedTableFactory(block_based_options));
  options.db_write_buffer_size = FLAGS_db_write_buffer_size;
  options.write_buffer_size = FLAGS_write_buffer_size;
  options.max_write_buffer_number = FLAGS_max_write_buffer_number;
  options.min_write_buffer_number_to_merge =
      FLAGS_min_write_buffer_number_to_merge;
  options.max_write_buffer_number_to_maintain =
      FLAGS_max_write_buffer_number_to_maintain;
  options.max_write_buffer_size_to_maintain =
      FLAGS_max_write_buffer_size_to_maintain;
  options.memtable_prefix_bloom_size_ratio =
      FLAGS_memtable_prefix_bloom_size_ratio;
  options.memtable_whole_key_filtering = FLAGS_memtable_whole_key_filtering;
  options.disable_auto_compactions = FLAGS_disable_auto_compactions;
  options.max_background_compactions = FLAGS_max_background_compactions;
  options.max_background_flushes = FLAGS_max_background_flushes;
  options.compaction_style =
      static_cast<ROCKSDB_NAMESPACE::CompactionStyle>(FLAGS_compaction_style);
  if (options.compaction_style ==
      ROCKSDB_NAMESPACE::CompactionStyle::kCompactionStyleFIFO) {
    options.compaction_options_fifo.allow_compaction =
        FLAGS_fifo_allow_compaction;
  }
  options.compaction_pri =
      static_cast<ROCKSDB_NAMESPACE::CompactionPri>(FLAGS_compaction_pri);
  options.num_levels = FLAGS_num_levels;
  if (FLAGS_prefix_size >= 0) {
    options.prefix_extractor.reset(NewFixedPrefixTransform(FLAGS_prefix_size));
  }
  options.max_open_files = FLAGS_open_files;
  options.statistics = dbstats;
  options.env = db_stress_env;
  options.use_fsync = FLAGS_use_fsync;
  options.compaction_readahead_size = FLAGS_compaction_readahead_size;
  options.allow_mmap_reads = FLAGS_mmap_read;
  options.allow_mmap_writes = FLAGS_mmap_write;
  options.use_direct_reads = FLAGS_use_direct_reads;
  options.use_direct_io_for_flush_and_compaction =
      FLAGS_use_direct_io_for_flush_and_compaction;
  options.recycle_log_file_num =
      static_cast<size_t>(FLAGS_recycle_log_file_num);
  options.target_file_size_base = FLAGS_target_file_size_base;
  options.target_file_size_multiplier = FLAGS_target_file_size_multiplier;
  options.max_bytes_for_level_base = FLAGS_max_bytes_for_level_base;
  options.max_bytes_for_level_multiplier = FLAGS_max_bytes_for_level_multiplier;
  options.level0_stop_writes_trigger = FLAGS_level0_stop_writes_trigger;
  options.level0_slowdown_writes_trigger = FLAGS_level0_slowdown_writes_trigger;
  options.level0_file_num_compaction_trigger =
      FLAGS_level0_file_num_compaction_trigger;
  options.compression = compression_type_e;
  options.bottommost_compression = bottommost_compression_type_e;
  options.compression_opts.max_dict_bytes = FLAGS_compression_max_dict_bytes;
  options.compression_opts.zstd_max_train_bytes =
      FLAGS_compression_zstd_max_train_bytes;
  options.compression_opts.parallel_threads =
      FLAGS_compression_parallel_threads;
  options.compression_opts.max_dict_buffer_bytes =
      FLAGS_compression_max_dict_buffer_bytes;
  if (ZSTD_FinalizeDictionarySupported()) {
    options.compression_opts.use_zstd_dict_trainer =
        FLAGS_compression_use_zstd_dict_trainer;
  } else if (!FLAGS_compression_use_zstd_dict_trainer) {
    fprintf(
        stderr,
        "WARNING: use_zstd_dict_trainer is false but zstd finalizeDictionary "
        "cannot be used because ZSTD 1.4.5+ is not linked with the binary."
        " zstd dictionary trainer will be used.\n");
  }
  options.max_manifest_file_size = FLAGS_max_manifest_file_size;
  options.inplace_update_support = FLAGS_in_place_update;
  options.max_subcompactions = static_cast<uint32_t>(FLAGS_subcompactions);
  options.allow_concurrent_memtable_write =
      FLAGS_allow_concurrent_memtable_write;
  options.experimental_mempurge_threshold =
      FLAGS_experimental_mempurge_threshold;
  options.periodic_compaction_seconds = FLAGS_periodic_compaction_seconds;
  options.stats_dump_period_sec =
      static_cast<unsigned int>(FLAGS_stats_dump_period_sec);
  options.ttl = FLAGS_compaction_ttl;
  options.enable_pipelined_write = FLAGS_enable_pipelined_write;
  options.enable_write_thread_adaptive_yield =
      FLAGS_enable_write_thread_adaptive_yield;
  options.compaction_options_universal.size_ratio = FLAGS_universal_size_ratio;
  options.compaction_options_universal.min_merge_width =
      FLAGS_universal_min_merge_width;
  options.compaction_options_universal.max_merge_width =
      FLAGS_universal_max_merge_width;
  options.compaction_options_universal.max_size_amplification_percent =
      FLAGS_universal_max_size_amplification_percent;
  options.atomic_flush = FLAGS_atomic_flush;
  options.manual_wal_flush = FLAGS_manual_wal_flush_one_in > 0 ? true : false;
  options.avoid_unnecessary_blocking_io = FLAGS_avoid_unnecessary_blocking_io;
  options.write_dbid_to_manifest = FLAGS_write_dbid_to_manifest;
  options.avoid_flush_during_recovery = FLAGS_avoid_flush_during_recovery;
  options.max_write_batch_group_size_bytes =
      FLAGS_max_write_batch_group_size_bytes;
  options.level_compaction_dynamic_level_bytes =
      FLAGS_level_compaction_dynamic_level_bytes;
  options.track_and_verify_wals_in_manifest = true;
  options.verify_sst_unique_id_in_manifest =
      FLAGS_verify_sst_unique_id_in_manifest;
  options.memtable_protection_bytes_per_key =
      FLAGS_memtable_protection_bytes_per_key;

  // Integrated BlobDB
  options.enable_blob_files = FLAGS_enable_blob_files;
  options.min_blob_size = FLAGS_min_blob_size;
  options.blob_file_size = FLAGS_blob_file_size;
  options.blob_compression_type =
      StringToCompressionType(FLAGS_blob_compression_type.c_str());
  options.enable_blob_garbage_collection = FLAGS_enable_blob_garbage_collection;
  options.blob_garbage_collection_age_cutoff =
      FLAGS_blob_garbage_collection_age_cutoff;
  options.blob_garbage_collection_force_threshold =
      FLAGS_blob_garbage_collection_force_threshold;
  options.blob_compaction_readahead_size = FLAGS_blob_compaction_readahead_size;
  options.blob_file_starting_level = FLAGS_blob_file_starting_level;

  if (FLAGS_use_blob_cache) {
    if (FLAGS_use_shared_block_and_blob_cache) {
      options.blob_cache = cache;
    } else {
      if (FLAGS_blob_cache_size > 0) {
        LRUCacheOptions co;
        co.capacity = FLAGS_blob_cache_size;
        co.num_shard_bits = FLAGS_blob_cache_numshardbits;
        options.blob_cache = NewLRUCache(co);
      } else {
        fprintf(stderr,
                "Unable to create a standalone blob cache if blob_cache_size "
                "<= 0.\n");
        exit(1);
      }
    }
    switch (FLAGS_prepopulate_blob_cache) {
      case 0:
        options.prepopulate_blob_cache = PrepopulateBlobCache::kDisable;
        break;
      case 1:
        options.prepopulate_blob_cache = PrepopulateBlobCache::kFlushOnly;
        break;
      default:
        fprintf(stderr, "Unknown prepopulate blob cache mode\n");
        exit(1);
    }
  }

  options.wal_compression =
      StringToCompressionType(FLAGS_wal_compression.c_str());

  if (FLAGS_enable_tiered_storage) {
    options.bottommost_temperature = Temperature::kCold;
  }
  options.preclude_last_level_data_seconds =
      FLAGS_preclude_last_level_data_seconds;
  options.preserve_internal_time_seconds = FLAGS_preserve_internal_time_seconds;

  switch (FLAGS_rep_factory) {
    case kSkipList:
      // no need to do anything
      break;
    case kHashSkipList:
      options.memtable_factory.reset(NewHashSkipListRepFactory(10000));
      break;
    case kVectorRep:
      options.memtable_factory.reset(new VectorRepFactory());
      break;
  }
  if (FLAGS_use_full_merge_v1) {
    options.merge_operator = MergeOperators::CreateDeprecatedPutOperator();
  } else {
    options.merge_operator = MergeOperators::CreatePutOperator();
  }

  if (FLAGS_enable_compaction_filter) {
    options.compaction_filter_factory =
        std::make_shared<DbStressCompactionFilterFactory>();
  }

  options.best_efforts_recovery = FLAGS_best_efforts_recovery;
  options.paranoid_file_checks = FLAGS_paranoid_file_checks;
  options.fail_if_options_file_error = FLAGS_fail_if_options_file_error;

  if (FLAGS_user_timestamp_size > 0) {
    CheckAndSetOptionsForUserTimestamp(options);
  }

  options.allow_data_in_errors = FLAGS_allow_data_in_errors;
}

void InitializeOptionsGeneral(
    const std::shared_ptr<Cache>& cache,
    const std::shared_ptr<const FilterPolicy>& filter_policy,
    Options& options) {
  options.create_missing_column_families = true;
  options.create_if_missing = true;

  if (!options.statistics) {
    options.statistics = dbstats;
  }

  if (options.env == Options().env) {
    options.env = db_stress_env;
  }

  assert(options.table_factory);
  auto table_options =
      options.table_factory->GetOptions<BlockBasedTableOptions>();
  if (table_options) {
    if (FLAGS_cache_size > 0) {
      table_options->block_cache = cache;
    }
    if (!table_options->filter_policy) {
      table_options->filter_policy = filter_policy;
    }
  }

  // TODO: row_cache, thread-pool IO priority, CPU priority.

  if (!options.rate_limiter) {
    if (FLAGS_rate_limiter_bytes_per_sec > 0) {
      options.rate_limiter.reset(NewGenericRateLimiter(
          FLAGS_rate_limiter_bytes_per_sec, 1000 /* refill_period_us */,
          10 /* fairness */,
          FLAGS_rate_limit_bg_reads ? RateLimiter::Mode::kReadsOnly
                                    : RateLimiter::Mode::kWritesOnly));
    }
  }

  if (!options.file_checksum_gen_factory) {
    options.file_checksum_gen_factory =
        GetFileChecksumImpl(FLAGS_file_checksum_impl);
  }

  if (FLAGS_sst_file_manager_bytes_per_sec > 0 ||
      FLAGS_sst_file_manager_bytes_per_truncate > 0) {
    Status status;
    options.sst_file_manager.reset(NewSstFileManager(
        db_stress_env, options.info_log, "" /* trash_dir */,
        static_cast<int64_t>(FLAGS_sst_file_manager_bytes_per_sec),
        true /* delete_existing_trash */, &status,
        0.25 /* max_trash_db_ratio */,
        FLAGS_sst_file_manager_bytes_per_truncate));
    if (!status.ok()) {
      fprintf(stderr, "SstFileManager creation failed: %s\n",
              status.ToString().c_str());
      exit(1);
    }
  }

  if (FLAGS_preserve_unverified_changes) {
    if (!options.avoid_flush_during_recovery) {
      fprintf(stderr,
              "WARNING: flipping `avoid_flush_during_recovery` to true for "
              "`preserve_unverified_changes` to keep all files\n");
      options.avoid_flush_during_recovery = true;
    }
    // Together with `avoid_flush_during_recovery == true`, this will prevent
    // live files from becoming obsolete and deleted between `DB::Open()` and
    // `DisableFileDeletions()` due to flush or compaction. We do not need to
    // warn the user since we will reenable compaction soon.
    options.disable_auto_compactions = true;
  }

  options.table_properties_collector_factories.emplace_back(
      std::make_shared<DbStressTablePropertiesCollectorFactory>());
}

}  // namespace ROCKSDB_NAMESPACE
#endif  // GFLAGS
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