Revision 4420df4b0e15ae88911e960c4fbafbaf8450fcf7 authored by Andrew Kryczka on 05 June 2018, 21:03:42 UTC, committed by Facebook Github Bot on 05 June 2018, 21:14:05 UTC
Summary: CompactFiles checked whether the existing files conflicted with the chosen compaction. But it missed checking whether future files would conflict, i.e., when another compaction was simultaneously writing new files to the same range at the same output level. Closes https://github.com/facebook/rocksdb/pull/3926 Differential Revision: D8218996 Pulled By: ajkr fbshipit-source-id: 21cb00a6fed4c8c62d3ed2ff810962e6bdc2fdfb
1 parent f1592a0
memtable_list.h
// 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).
//
#pragma once
#include <deque>
#include <limits>
#include <list>
#include <set>
#include <string>
#include <vector>
#include "db/dbformat.h"
#include "db/logs_with_prep_tracker.h"
#include "db/memtable.h"
#include "db/range_del_aggregator.h"
#include "monitoring/instrumented_mutex.h"
#include "rocksdb/db.h"
#include "rocksdb/iterator.h"
#include "rocksdb/options.h"
#include "rocksdb/types.h"
#include "util/autovector.h"
#include "util/filename.h"
#include "util/log_buffer.h"
namespace rocksdb {
class ColumnFamilyData;
class InternalKeyComparator;
class InstrumentedMutex;
class MergeIteratorBuilder;
// keeps a list of immutable memtables in a vector. the list is immutable
// if refcount is bigger than one. It is used as a state for Get() and
// Iterator code paths
//
// This class is not thread-safe. External synchronization is required
// (such as holding the db mutex or being on the write thread).
class MemTableListVersion {
public:
explicit MemTableListVersion(size_t* parent_memtable_list_memory_usage,
MemTableListVersion* old = nullptr);
explicit MemTableListVersion(size_t* parent_memtable_list_memory_usage,
int max_write_buffer_number_to_maintain);
void Ref();
void Unref(autovector<MemTable*>* to_delete = nullptr);
// Search all the memtables starting from the most recent one.
// Return the most recent value found, if any.
//
// If any operation was found for this key, its most recent sequence number
// will be stored in *seq on success (regardless of whether true/false is
// returned). Otherwise, *seq will be set to kMaxSequenceNumber.
bool Get(const LookupKey& key, std::string* value, Status* s,
MergeContext* merge_context, RangeDelAggregator* range_del_agg,
SequenceNumber* seq, const ReadOptions& read_opts,
ReadCallback* callback = nullptr, bool* is_blob_index = nullptr);
bool Get(const LookupKey& key, std::string* value, Status* s,
MergeContext* merge_context, RangeDelAggregator* range_del_agg,
const ReadOptions& read_opts, ReadCallback* callback = nullptr,
bool* is_blob_index = nullptr) {
SequenceNumber seq;
return Get(key, value, s, merge_context, range_del_agg, &seq, read_opts,
callback, is_blob_index);
}
// Similar to Get(), but searches the Memtable history of memtables that
// have already been flushed. Should only be used from in-memory only
// queries (such as Transaction validation) as the history may contain
// writes that are also present in the SST files.
bool GetFromHistory(const LookupKey& key, std::string* value, Status* s,
MergeContext* merge_context,
RangeDelAggregator* range_del_agg, SequenceNumber* seq,
const ReadOptions& read_opts,
bool* is_blob_index = nullptr);
bool GetFromHistory(const LookupKey& key, std::string* value, Status* s,
MergeContext* merge_context,
RangeDelAggregator* range_del_agg,
const ReadOptions& read_opts,
bool* is_blob_index = nullptr) {
SequenceNumber seq;
return GetFromHistory(key, value, s, merge_context, range_del_agg, &seq,
read_opts, is_blob_index);
}
Status AddRangeTombstoneIterators(const ReadOptions& read_opts, Arena* arena,
RangeDelAggregator* range_del_agg);
Status AddRangeTombstoneIterators(
const ReadOptions& read_opts,
std::vector<InternalIterator*>* range_del_iters);
void AddIterators(const ReadOptions& options,
std::vector<InternalIterator*>* iterator_list,
Arena* arena);
void AddIterators(const ReadOptions& options,
MergeIteratorBuilder* merge_iter_builder);
uint64_t GetTotalNumEntries() const;
uint64_t GetTotalNumDeletes() const;
MemTable::MemTableStats ApproximateStats(const Slice& start_ikey,
const Slice& end_ikey);
// Returns the value of MemTable::GetEarliestSequenceNumber() on the most
// recent MemTable in this list or kMaxSequenceNumber if the list is empty.
// If include_history=true, will also search Memtables in MemTableList
// History.
SequenceNumber GetEarliestSequenceNumber(bool include_history = false) const;
private:
// REQUIRE: m is an immutable memtable
void Add(MemTable* m, autovector<MemTable*>* to_delete);
// REQUIRE: m is an immutable memtable
void Remove(MemTable* m, autovector<MemTable*>* to_delete);
void TrimHistory(autovector<MemTable*>* to_delete);
bool GetFromList(std::list<MemTable*>* list, const LookupKey& key,
std::string* value, Status* s, MergeContext* merge_context,
RangeDelAggregator* range_del_agg, SequenceNumber* seq,
const ReadOptions& read_opts,
ReadCallback* callback = nullptr,
bool* is_blob_index = nullptr);
void AddMemTable(MemTable* m);
void UnrefMemTable(autovector<MemTable*>* to_delete, MemTable* m);
friend class MemTableList;
// Immutable MemTables that have not yet been flushed.
std::list<MemTable*> memlist_;
// MemTables that have already been flushed
// (used during Transaction validation)
std::list<MemTable*> memlist_history_;
// Maximum number of MemTables to keep in memory (including both flushed
// and not-yet-flushed tables).
const int max_write_buffer_number_to_maintain_;
int refs_ = 0;
size_t* parent_memtable_list_memory_usage_;
};
// This class stores references to all the immutable memtables.
// The memtables are flushed to L0 as soon as possible and in
// any order. If there are more than one immutable memtable, their
// flushes can occur concurrently. However, they are 'committed'
// to the manifest in FIFO order to maintain correctness and
// recoverability from a crash.
//
//
// Other than imm_flush_needed, this class is not thread-safe and requires
// external synchronization (such as holding the db mutex or being on the
// write thread.)
class MemTableList {
public:
// A list of memtables.
explicit MemTableList(int min_write_buffer_number_to_merge,
int max_write_buffer_number_to_maintain)
: imm_flush_needed(false),
min_write_buffer_number_to_merge_(min_write_buffer_number_to_merge),
current_(new MemTableListVersion(¤t_memory_usage_,
max_write_buffer_number_to_maintain)),
num_flush_not_started_(0),
commit_in_progress_(false),
flush_requested_(false) {
current_->Ref();
current_memory_usage_ = 0;
}
// Should not delete MemTableList without making sure MemTableList::current()
// is Unref()'d.
~MemTableList() {}
MemTableListVersion* current() { return current_; }
// so that background threads can detect non-nullptr pointer to
// determine whether there is anything more to start flushing.
std::atomic<bool> imm_flush_needed;
// Returns the total number of memtables in the list that haven't yet
// been flushed and logged.
int NumNotFlushed() const;
// Returns total number of memtables in the list that have been
// completely flushed and logged.
int NumFlushed() const;
// Returns true if there is at least one memtable on which flush has
// not yet started.
bool IsFlushPending() const;
// Returns the earliest memtables that needs to be flushed. The returned
// memtables are guaranteed to be in the ascending order of created time.
void PickMemtablesToFlush(autovector<MemTable*>* mems);
// Reset status of the given memtable list back to pending state so that
// they can get picked up again on the next round of flush.
void RollbackMemtableFlush(const autovector<MemTable*>& mems,
uint64_t file_number);
// Commit a successful flush in the manifest file
Status InstallMemtableFlushResults(
ColumnFamilyData* cfd, const MutableCFOptions& mutable_cf_options,
const autovector<MemTable*>& m, LogsWithPrepTracker* prep_tracker,
VersionSet* vset, InstrumentedMutex* mu, uint64_t file_number,
autovector<MemTable*>* to_delete, Directory* db_directory,
LogBuffer* log_buffer);
// New memtables are inserted at the front of the list.
// Takes ownership of the referenced held on *m by the caller of Add().
void Add(MemTable* m, autovector<MemTable*>* to_delete);
// Returns an estimate of the number of bytes of data in use.
size_t ApproximateMemoryUsage();
// Returns an estimate of the number of bytes of data used by
// the unflushed mem-tables.
size_t ApproximateUnflushedMemTablesMemoryUsage();
// Returns an estimate of the timestamp of the earliest key.
uint64_t ApproximateOldestKeyTime() const;
// Request a flush of all existing memtables to storage. This will
// cause future calls to IsFlushPending() to return true if this list is
// non-empty (regardless of the min_write_buffer_number_to_merge
// parameter). This flush request will persist until the next time
// PickMemtablesToFlush() is called.
void FlushRequested() { flush_requested_ = true; }
bool HasFlushRequested() { return flush_requested_; }
// Copying allowed
// MemTableList(const MemTableList&);
// void operator=(const MemTableList&);
size_t* current_memory_usage() { return ¤t_memory_usage_; }
// Returns the min log containing the prep section after memtables listsed in
// `memtables_to_flush` are flushed and their status is persisted in manifest.
uint64_t PrecomputeMinLogContainingPrepSection(
const autovector<MemTable*>& memtables_to_flush);
uint64_t GetEarliestMemTableID() const {
auto& memlist = current_->memlist_;
if (memlist.empty()) {
return std::numeric_limits<uint64_t>::max();
}
return memlist.back()->GetID();
}
uint64_t GetLatestMemTableID() const {
auto& memlist = current_->memlist_;
if (memlist.empty()) {
return 0;
}
return memlist.front()->GetID();
}
private:
// DB mutex held
void InstallNewVersion();
const int min_write_buffer_number_to_merge_;
MemTableListVersion* current_;
// the number of elements that still need flushing
int num_flush_not_started_;
// committing in progress
bool commit_in_progress_;
// Requested a flush of all memtables to storage
bool flush_requested_;
// The current memory usage.
size_t current_memory_usage_;
};
} // namespace rocksdb
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