Revision 499ebb3ab5ea4207950fc95acf102b8f58add1c5 authored by Maysam Yabandeh on 24 June 2017, 21:06:43 UTC, committed by Facebook Github Bot on 24 June 2017, 21:11:29 UTC
Summary:
Throughput: 46k tps in our sysbench settings (filling the details later)

The idea is to have the simplest change that gives us a reasonable boost
in 2PC throughput.

Major design changes:
1. The WAL file internal buffer is not flushed after each write. Instead
it is flushed before critical operations (WAL copy via fs) or when
FlushWAL is called by MySQL. Flushing the WAL buffer is also protected
via mutex_.
2. Use two sequence numbers: last seq, and last seq for write. Last seq
is the last visible sequence number for reads. Last seq for write is the
next sequence number that should be used to write to WAL/memtable. This
allows to have a memtable write be in parallel to WAL writes.
3. BatchGroup is not used for writes. This means that we can have
parallel writers which changes a major assumption in the code base. To
accommodate for that i) allow only 1 WriteImpl that intends to write to
memtable via mem_mutex_--which is fine since in 2PC almost all of the memtable writes
come via group commit phase which is serial anyway, ii) make all the
parts in the code base that assumed to be the only writer (via
EnterUnbatched) to also acquire mem_mutex_, iii) stat updates are
protected via a stat_mutex_.

Note: the first commit has the approach figured out but is not clean.
Submitting the PR anyway to get the early feedback on the approach. If
we are ok with the approach I will go ahead with this updates:
0) Rebase with Yi's pipelining changes
1) Currently batching is disabled by default to make sure that it will be
consistent with all unit tests. Will make this optional via a config.
2) A couple of unit tests are disabled. They need to be updated with the
serial commit of 2PC taken into account.
3) Replacing BatchGroup with mem_mutex_ got a bit ugly as it requires
releasing mutex_ beforehand (the same way EnterUnbatched does). This
needs to be cleaned up.
Closes https://github.com/facebook/rocksdb/pull/2345

Differential Revision: D5210732

Pulled By: maysamyabandeh

fbshipit-source-id: 78653bd95a35cd1e831e555e0e57bdfd695355a4
1 parent 0ac4afb
Raw File
db_options_test.cc
//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
//  This source code is licensed under the BSD-style license found in the
//  LICENSE file in the root directory of this source tree. An additional grant
//  of patent rights can be found in the PATENTS file in the same directory.
//  This source code is also licensed under the GPLv2 license found in the
//  COPYING file in the root directory of this source tree.
//
// 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 <limits>
#include <string>
#include <unordered_map>

#include "db/column_family.h"
#include "db/db_impl.h"
#include "db/db_test_util.h"
#include "options/options_helper.h"
#include "port/stack_trace.h"
#include "rocksdb/cache.h"
#include "rocksdb/convenience.h"
#include "rocksdb/rate_limiter.h"
#include "util/random.h"
#include "util/sync_point.h"
#include "util/testutil.h"

namespace rocksdb {

class DBOptionsTest : public DBTestBase {
 public:
  DBOptionsTest() : DBTestBase("/db_options_test") {}

#ifndef ROCKSDB_LITE
  std::unordered_map<std::string, std::string> GetMutableDBOptionsMap(
      const DBOptions& options) {
    std::string options_str;
    GetStringFromDBOptions(&options_str, options);
    std::unordered_map<std::string, std::string> options_map;
    StringToMap(options_str, &options_map);
    std::unordered_map<std::string, std::string> mutable_map;
    for (const auto opt : db_options_type_info) {
      if (opt.second.is_mutable &&
          opt.second.verification != OptionVerificationType::kDeprecated) {
        mutable_map[opt.first] = options_map[opt.first];
      }
    }
    return mutable_map;
  }

  std::unordered_map<std::string, std::string> GetMutableCFOptionsMap(
      const ColumnFamilyOptions& options) {
    std::string options_str;
    GetStringFromColumnFamilyOptions(&options_str, options);
    std::unordered_map<std::string, std::string> options_map;
    StringToMap(options_str, &options_map);
    std::unordered_map<std::string, std::string> mutable_map;
    for (const auto opt : cf_options_type_info) {
      if (opt.second.is_mutable &&
          opt.second.verification != OptionVerificationType::kDeprecated) {
        mutable_map[opt.first] = options_map[opt.first];
      }
    }
    return mutable_map;
  }

  std::unordered_map<std::string, std::string> GetRandomizedMutableCFOptionsMap(
      Random* rnd) {
    Options options;
    options.env = env_;
    ImmutableDBOptions db_options(options);
    test::RandomInitCFOptions(&options, rnd);
    auto sanitized_options = SanitizeOptions(db_options, options);
    auto opt_map = GetMutableCFOptionsMap(sanitized_options);
    delete options.compaction_filter;
    return opt_map;
  }

  std::unordered_map<std::string, std::string> GetRandomizedMutableDBOptionsMap(
      Random* rnd) {
    DBOptions db_options;
    test::RandomInitDBOptions(&db_options, rnd);
    auto sanitized_options = SanitizeOptions(dbname_, db_options);
    return GetMutableDBOptionsMap(sanitized_options);
  }
#endif  // ROCKSDB_LITE
};

// RocksDB lite don't support dynamic options.
#ifndef ROCKSDB_LITE

TEST_F(DBOptionsTest, GetLatestDBOptions) {
  // GetOptions should be able to get latest option changed by SetOptions.
  Options options;
  options.create_if_missing = true;
  options.env = env_;
  Random rnd(228);
  Reopen(options);
  auto new_options = GetRandomizedMutableDBOptionsMap(&rnd);
  ASSERT_OK(dbfull()->SetDBOptions(new_options));
  ASSERT_EQ(new_options, GetMutableDBOptionsMap(dbfull()->GetDBOptions()));
}

TEST_F(DBOptionsTest, GetLatestCFOptions) {
  // GetOptions should be able to get latest option changed by SetOptions.
  Options options;
  options.create_if_missing = true;
  options.env = env_;
  Random rnd(228);
  Reopen(options);
  CreateColumnFamilies({"foo"}, options);
  ReopenWithColumnFamilies({"default", "foo"}, options);
  auto options_default = GetRandomizedMutableCFOptionsMap(&rnd);
  auto options_foo = GetRandomizedMutableCFOptionsMap(&rnd);
  ASSERT_OK(dbfull()->SetOptions(handles_[0], options_default));
  ASSERT_OK(dbfull()->SetOptions(handles_[1], options_foo));
  ASSERT_EQ(options_default,
            GetMutableCFOptionsMap(dbfull()->GetOptions(handles_[0])));
  ASSERT_EQ(options_foo,
            GetMutableCFOptionsMap(dbfull()->GetOptions(handles_[1])));
}

TEST_F(DBOptionsTest, SetOptionsAndReopen) {
  Random rnd(1044);
  auto rand_opts = GetRandomizedMutableCFOptionsMap(&rnd);
  ASSERT_OK(dbfull()->SetOptions(rand_opts));
  // Verify if DB can be reopen after setting options.
  Options options;
  options.env = env_;
  ASSERT_OK(TryReopen(options));
}

TEST_F(DBOptionsTest, EnableAutoCompactionAndTriggerStall) {
  const std::string kValue(1024, 'v');
  for (int method_type = 0; method_type < 2; method_type++) {
    for (int option_type = 0; option_type < 4; option_type++) {
      Options options;
      options.create_if_missing = true;
      options.disable_auto_compactions = true;
      options.write_buffer_size = 1024 * 1024 * 10;
      options.compression = CompressionType::kNoCompression;
      options.level0_file_num_compaction_trigger = 1;
      options.level0_stop_writes_trigger = std::numeric_limits<int>::max();
      options.level0_slowdown_writes_trigger = std::numeric_limits<int>::max();
      options.hard_pending_compaction_bytes_limit =
          std::numeric_limits<uint64_t>::max();
      options.soft_pending_compaction_bytes_limit =
          std::numeric_limits<uint64_t>::max();
      options.env = env_;

      DestroyAndReopen(options);
      int i = 0;
      for (; i < 1024; i++) {
        Put(Key(i), kValue);
      }
      Flush();
      for (; i < 1024 * 2; i++) {
        Put(Key(i), kValue);
      }
      Flush();
      dbfull()->TEST_WaitForFlushMemTable();
      ASSERT_EQ(2, NumTableFilesAtLevel(0));
      uint64_t l0_size = SizeAtLevel(0);

      switch (option_type) {
        case 0:
          // test with level0_stop_writes_trigger
          options.level0_stop_writes_trigger = 2;
          options.level0_slowdown_writes_trigger = 2;
          break;
        case 1:
          options.level0_slowdown_writes_trigger = 2;
          break;
        case 2:
          options.hard_pending_compaction_bytes_limit = l0_size;
          options.soft_pending_compaction_bytes_limit = l0_size;
          break;
        case 3:
          options.soft_pending_compaction_bytes_limit = l0_size;
          break;
      }
      Reopen(options);
      dbfull()->TEST_WaitForCompact();
      ASSERT_FALSE(dbfull()->TEST_write_controler().IsStopped());
      ASSERT_FALSE(dbfull()->TEST_write_controler().NeedsDelay());

      SyncPoint::GetInstance()->LoadDependency(
          {{"DBOptionsTest::EnableAutoCompactionAndTriggerStall:1",
            "BackgroundCallCompaction:0"},
           {"DBImpl::BackgroundCompaction():BeforePickCompaction",
            "DBOptionsTest::EnableAutoCompactionAndTriggerStall:2"},
           {"DBOptionsTest::EnableAutoCompactionAndTriggerStall:3",
            "DBImpl::BackgroundCompaction():AfterPickCompaction"}});
      // Block background compaction.
      SyncPoint::GetInstance()->EnableProcessing();

      switch (method_type) {
        case 0:
          ASSERT_OK(
              dbfull()->SetOptions({{"disable_auto_compactions", "false"}}));
          break;
        case 1:
          ASSERT_OK(dbfull()->EnableAutoCompaction(
              {dbfull()->DefaultColumnFamily()}));
          break;
      }
      TEST_SYNC_POINT("DBOptionsTest::EnableAutoCompactionAndTriggerStall:1");
      // Wait for stall condition recalculate.
      TEST_SYNC_POINT("DBOptionsTest::EnableAutoCompactionAndTriggerStall:2");

      switch (option_type) {
        case 0:
          ASSERT_TRUE(dbfull()->TEST_write_controler().IsStopped());
          break;
        case 1:
          ASSERT_FALSE(dbfull()->TEST_write_controler().IsStopped());
          ASSERT_TRUE(dbfull()->TEST_write_controler().NeedsDelay());
          break;
        case 2:
          ASSERT_TRUE(dbfull()->TEST_write_controler().IsStopped());
          break;
        case 3:
          ASSERT_FALSE(dbfull()->TEST_write_controler().IsStopped());
          ASSERT_TRUE(dbfull()->TEST_write_controler().NeedsDelay());
          break;
      }
      TEST_SYNC_POINT("DBOptionsTest::EnableAutoCompactionAndTriggerStall:3");

      // Background compaction executed.
      dbfull()->TEST_WaitForCompact();
      ASSERT_FALSE(dbfull()->TEST_write_controler().IsStopped());
      ASSERT_FALSE(dbfull()->TEST_write_controler().NeedsDelay());
    }
  }
}

TEST_F(DBOptionsTest, SetOptionsMayTriggerCompaction) {
  Options options;
  options.create_if_missing = true;
  options.level0_file_num_compaction_trigger = 1000;
  options.env = env_;
  Reopen(options);
  for (int i = 0; i < 3; i++) {
    // Need to insert two keys to avoid trivial move.
    ASSERT_OK(Put("foo", ToString(i)));
    ASSERT_OK(Put("bar", ToString(i)));
    Flush();
  }
  ASSERT_EQ("3", FilesPerLevel());
  ASSERT_OK(
      dbfull()->SetOptions({{"level0_file_num_compaction_trigger", "3"}}));
  dbfull()->TEST_WaitForCompact();
  ASSERT_EQ("0,1", FilesPerLevel());
}

TEST_F(DBOptionsTest, SetBackgroundCompactionThreads) {
  Options options;
  options.create_if_missing = true;
  options.max_background_compactions = 1;   // default value
  options.env = env_;
  Reopen(options);
  ASSERT_EQ(1, dbfull()->TEST_BGCompactionsAllowed());
  ASSERT_OK(dbfull()->SetDBOptions({{"max_background_compactions", "3"}}));
  ASSERT_EQ(1, dbfull()->TEST_BGCompactionsAllowed());
  auto stop_token = dbfull()->TEST_write_controler().GetStopToken();
  ASSERT_EQ(3, dbfull()->TEST_BGCompactionsAllowed());
}

TEST_F(DBOptionsTest, SetBackgroundJobs) {
  Options options;
  options.create_if_missing = true;
  options.max_background_jobs = 8;
  options.env = env_;
  Reopen(options);

  for (int i = 0; i < 2; ++i) {
    if (i > 0) {
      options.max_background_jobs = 12;
      ASSERT_OK(dbfull()->SetDBOptions(
          {{"max_background_jobs",
            std::to_string(options.max_background_jobs)}}));
    }

    ASSERT_EQ(options.max_background_jobs / 4,
              dbfull()->TEST_BGFlushesAllowed());
    ASSERT_EQ(1, dbfull()->TEST_BGCompactionsAllowed());

    auto stop_token = dbfull()->TEST_write_controler().GetStopToken();

    ASSERT_EQ(options.max_background_jobs / 4,
              dbfull()->TEST_BGFlushesAllowed());
    ASSERT_EQ(3 * options.max_background_jobs / 4,
              dbfull()->TEST_BGCompactionsAllowed());
  }
}

TEST_F(DBOptionsTest, AvoidFlushDuringShutdown) {
  Options options;
  options.create_if_missing = true;
  options.disable_auto_compactions = true;
  options.env = env_;
  WriteOptions write_without_wal;
  write_without_wal.disableWAL = true;

  ASSERT_FALSE(options.avoid_flush_during_shutdown);
  DestroyAndReopen(options);
  ASSERT_OK(Put("foo", "v1", write_without_wal));
  Reopen(options);
  ASSERT_EQ("v1", Get("foo"));
  ASSERT_EQ("1", FilesPerLevel());

  DestroyAndReopen(options);
  ASSERT_OK(Put("foo", "v2", write_without_wal));
  ASSERT_OK(dbfull()->SetDBOptions({{"avoid_flush_during_shutdown", "true"}}));
  Reopen(options);
  ASSERT_EQ("NOT_FOUND", Get("foo"));
  ASSERT_EQ("", FilesPerLevel());
}

TEST_F(DBOptionsTest, SetDelayedWriteRateOption) {
  Options options;
  options.create_if_missing = true;
  options.delayed_write_rate = 2 * 1024U * 1024U;
  options.env = env_;
  Reopen(options);
  ASSERT_EQ(2 * 1024U * 1024U, dbfull()->TEST_write_controler().max_delayed_write_rate());

  ASSERT_OK(dbfull()->SetDBOptions({{"delayed_write_rate", "20000"}}));
  ASSERT_EQ(20000, dbfull()->TEST_write_controler().max_delayed_write_rate());
}

TEST_F(DBOptionsTest, MaxTotalWalSizeChange) {
  Random rnd(1044);
  const auto value_size = size_t(1024);
  std::string value;
  test::RandomString(&rnd, value_size, &value);

  Options options;
  options.create_if_missing = true;
  options.env = env_;
  CreateColumnFamilies({"1", "2", "3"}, options);
  ReopenWithColumnFamilies({"default", "1", "2", "3"}, options);

  WriteOptions write_options;

  const int key_count = 100;
  for (int i = 0; i < key_count; ++i) {
    for (size_t cf = 0; cf < handles_.size(); ++cf) {
      ASSERT_OK(Put(static_cast<int>(cf), Key(i), value));
    }
  }
  ASSERT_OK(dbfull()->SetDBOptions({{"max_total_wal_size", "10"}}));

  for (size_t cf = 0; cf < handles_.size(); ++cf) {
    dbfull()->TEST_WaitForFlushMemTable(handles_[cf]);
    ASSERT_EQ("1", FilesPerLevel(static_cast<int>(cf)));
  }
}

TEST_F(DBOptionsTest, SetStatsDumpPeriodSec) {
  Options options;
  options.create_if_missing = true;
  options.stats_dump_period_sec = 5;
  options.env = env_;
  Reopen(options);
  ASSERT_EQ(5, dbfull()->GetDBOptions().stats_dump_period_sec);

  for (int i = 0; i < 20; i++) {
    int num = rand() % 5000 + 1;
    ASSERT_OK(dbfull()->SetDBOptions(
        {{"stats_dump_period_sec", std::to_string(num)}}));
    ASSERT_EQ(num, dbfull()->GetDBOptions().stats_dump_period_sec);
  }
}

static void assert_candidate_files_empty(DBImpl* dbfull, const bool empty) {
  dbfull->TEST_LockMutex();
  JobContext job_context(0);
  dbfull->FindObsoleteFiles(&job_context, false);
  ASSERT_EQ(empty, job_context.full_scan_candidate_files.empty());
  job_context.Clean();
  dbfull->TEST_UnlockMutex();
}

TEST_F(DBOptionsTest, DeleteObsoleteFilesPeriodChange) {
  SpecialEnv env(env_);
  env.time_elapse_only_sleep_ = true;
  Options options;
  options.env = &env;
  options.create_if_missing = true;
  ASSERT_OK(TryReopen(options));

  // Verify that candidate files set is empty when no full scan requested.
  assert_candidate_files_empty(dbfull(), true);

  ASSERT_OK(
      dbfull()->SetDBOptions({{"delete_obsolete_files_period_micros", "0"}}));

  // After delete_obsolete_files_period_micros updated to 0, the next call
  // to FindObsoleteFiles should make a full scan
  assert_candidate_files_empty(dbfull(), false);

  ASSERT_OK(
      dbfull()->SetDBOptions({{"delete_obsolete_files_period_micros", "20"}}));

  assert_candidate_files_empty(dbfull(), true);

  env.addon_time_.store(20);
  assert_candidate_files_empty(dbfull(), true);

  env.addon_time_.store(21);
  assert_candidate_files_empty(dbfull(), false);

  Close();
}

TEST_F(DBOptionsTest, MaxOpenFilesChange) {
  SpecialEnv env(env_);
  Options options;
  options.max_open_files = -1;

  Reopen(options);

  Cache* tc = dbfull()->TEST_table_cache();

  ASSERT_EQ(-1, dbfull()->GetDBOptions().max_open_files);
  ASSERT_LT(2000, tc->GetCapacity());
  ASSERT_OK(dbfull()->SetDBOptions({{"max_open_files", "1024"}}));
  ASSERT_EQ(1024, dbfull()->GetDBOptions().max_open_files);
  // examine the table cache (actual size should be 1014)
  ASSERT_GT(1500, tc->GetCapacity());
  Close();
}

TEST_F(DBOptionsTest, SanitizeDelayedWriteRate) {
  Options options;
  options.delayed_write_rate = 0;
  Reopen(options);
  ASSERT_EQ(16 * 1024 * 1024, dbfull()->GetDBOptions().delayed_write_rate);

  options.rate_limiter.reset(NewGenericRateLimiter(31 * 1024 * 1024));
  Reopen(options);
  ASSERT_EQ(31 * 1024 * 1024, dbfull()->GetDBOptions().delayed_write_rate);
}

#endif  // ROCKSDB_LITE

}  // namespace rocksdb

int main(int argc, char** argv) {
  rocksdb::port::InstallStackTraceHandler();
  ::testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}
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