rocksdb/db/compaction_job.cc
Abhishek Madan 64aabc9183 Properly set smallest key of subcompaction output (#4723)
Summary:
It is possible to see a situation like the following when
subcompactions are enabled:
1. A subcompaction boundary is set to `[b, e)`.
2. The first output file in a subcompaction has `c@20` as its smallest key
3. The range tombstone `[a, d)30` is encountered.
4. The tombstone is written to the range-del meta block and the new
   smallest key is set to `b@0` (since no keys in this subcompaction's
   output can be smaller than `b`).
5. A key `b@10` in a lower level will now reappear, since it is not
   covered by the truncated start key `b@0`.

In general, unless the smallest data key in a file has a seqnum of 0, it
is not safe to truncate a tombstone at the start key to have a seqnum of
0, since it can expose keys with a seqnum greater than 0 but less than
the tombstone's actual seqnum.

To fix this, when the lower bound of a file is from the subcompaction
boundaries, we now set the seqnum of an artificially extended smallest
key to the tombstone's seqnum. This is safe because subcompactions
operate over disjoint sets of keys, and the subcompactions that can
experience this problem are not the first subcompaction (which is
unbounded on the left).

Furthermore, there is now an assertion to detect the described anomalous
case.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4723

Differential Revision: D13236188

Pulled By: abhimadan

fbshipit-source-id: a6da6a113f2de1e2ff307ca72e055300c8fe5692
2018-12-10 12:38:31 -08:00

1721 lines
67 KiB
C++

// 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 "db/compaction_job.h"
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#include <algorithm>
#include <functional>
#include <list>
#include <memory>
#include <random>
#include <set>
#include <thread>
#include <utility>
#include <vector>
#include "db/builder.h"
#include "db/db_impl.h"
#include "db/db_iter.h"
#include "db/dbformat.h"
#include "db/error_handler.h"
#include "db/event_helpers.h"
#include "db/log_reader.h"
#include "db/log_writer.h"
#include "db/memtable.h"
#include "db/memtable_list.h"
#include "db/merge_context.h"
#include "db/merge_helper.h"
#include "db/range_del_aggregator_v2.h"
#include "db/version_set.h"
#include "monitoring/iostats_context_imp.h"
#include "monitoring/perf_context_imp.h"
#include "monitoring/thread_status_util.h"
#include "port/port.h"
#include "rocksdb/db.h"
#include "rocksdb/env.h"
#include "rocksdb/statistics.h"
#include "rocksdb/status.h"
#include "rocksdb/table.h"
#include "table/block.h"
#include "table/block_based_table_factory.h"
#include "table/merging_iterator.h"
#include "table/table_builder.h"
#include "util/coding.h"
#include "util/file_reader_writer.h"
#include "util/filename.h"
#include "util/log_buffer.h"
#include "util/logging.h"
#include "util/mutexlock.h"
#include "util/random.h"
#include "util/sst_file_manager_impl.h"
#include "util/stop_watch.h"
#include "util/string_util.h"
#include "util/sync_point.h"
namespace rocksdb {
const char* GetCompactionReasonString(CompactionReason compaction_reason) {
switch (compaction_reason) {
case CompactionReason::kUnknown:
return "Unknown";
case CompactionReason::kLevelL0FilesNum:
return "LevelL0FilesNum";
case CompactionReason::kLevelMaxLevelSize:
return "LevelMaxLevelSize";
case CompactionReason::kUniversalSizeAmplification:
return "UniversalSizeAmplification";
case CompactionReason::kUniversalSizeRatio:
return "UniversalSizeRatio";
case CompactionReason::kUniversalSortedRunNum:
return "UniversalSortedRunNum";
case CompactionReason::kFIFOMaxSize:
return "FIFOMaxSize";
case CompactionReason::kFIFOReduceNumFiles:
return "FIFOReduceNumFiles";
case CompactionReason::kFIFOTtl:
return "FIFOTtl";
case CompactionReason::kManualCompaction:
return "ManualCompaction";
case CompactionReason::kFilesMarkedForCompaction:
return "FilesMarkedForCompaction";
case CompactionReason::kBottommostFiles:
return "BottommostFiles";
case CompactionReason::kTtl:
return "Ttl";
case CompactionReason::kFlush:
return "Flush";
case CompactionReason::kExternalSstIngestion:
return "ExternalSstIngestion";
case CompactionReason::kNumOfReasons:
// fall through
default:
assert(false);
return "Invalid";
}
}
// Maintains state for each sub-compaction
struct CompactionJob::SubcompactionState {
const Compaction* compaction;
std::unique_ptr<CompactionIterator> c_iter;
// The boundaries of the key-range this compaction is interested in. No two
// subcompactions may have overlapping key-ranges.
// 'start' is inclusive, 'end' is exclusive, and nullptr means unbounded
Slice *start, *end;
// The return status of this subcompaction
Status status;
// Files produced by this subcompaction
struct Output {
FileMetaData meta;
bool finished;
std::shared_ptr<const TableProperties> table_properties;
};
// State kept for output being generated
std::vector<Output> outputs;
std::unique_ptr<WritableFileWriter> outfile;
std::unique_ptr<TableBuilder> builder;
Output* current_output() {
if (outputs.empty()) {
// This subcompaction's outptut could be empty if compaction was aborted
// before this subcompaction had a chance to generate any output files.
// When subcompactions are executed sequentially this is more likely and
// will be particulalry likely for the later subcompactions to be empty.
// Once they are run in parallel however it should be much rarer.
return nullptr;
} else {
return &outputs.back();
}
}
uint64_t current_output_file_size;
// State during the subcompaction
uint64_t total_bytes;
uint64_t num_input_records;
uint64_t num_output_records;
CompactionJobStats compaction_job_stats;
uint64_t approx_size;
// An index that used to speed up ShouldStopBefore().
size_t grandparent_index = 0;
// The number of bytes overlapping between the current output and
// grandparent files used in ShouldStopBefore().
uint64_t overlapped_bytes = 0;
// A flag determine whether the key has been seen in ShouldStopBefore()
bool seen_key = false;
std::string compression_dict;
SubcompactionState(Compaction* c, Slice* _start, Slice* _end,
uint64_t size = 0)
: compaction(c),
start(_start),
end(_end),
outfile(nullptr),
builder(nullptr),
current_output_file_size(0),
total_bytes(0),
num_input_records(0),
num_output_records(0),
approx_size(size),
grandparent_index(0),
overlapped_bytes(0),
seen_key(false),
compression_dict() {
assert(compaction != nullptr);
}
SubcompactionState(SubcompactionState&& o) { *this = std::move(o); }
SubcompactionState& operator=(SubcompactionState&& o) {
compaction = std::move(o.compaction);
start = std::move(o.start);
end = std::move(o.end);
status = std::move(o.status);
outputs = std::move(o.outputs);
outfile = std::move(o.outfile);
builder = std::move(o.builder);
current_output_file_size = std::move(o.current_output_file_size);
total_bytes = std::move(o.total_bytes);
num_input_records = std::move(o.num_input_records);
num_output_records = std::move(o.num_output_records);
compaction_job_stats = std::move(o.compaction_job_stats);
approx_size = std::move(o.approx_size);
grandparent_index = std::move(o.grandparent_index);
overlapped_bytes = std::move(o.overlapped_bytes);
seen_key = std::move(o.seen_key);
compression_dict = std::move(o.compression_dict);
return *this;
}
// Because member std::unique_ptrs do not have these.
SubcompactionState(const SubcompactionState&) = delete;
SubcompactionState& operator=(const SubcompactionState&) = delete;
// Returns true iff we should stop building the current output
// before processing "internal_key".
bool ShouldStopBefore(const Slice& internal_key, uint64_t curr_file_size) {
const InternalKeyComparator* icmp =
&compaction->column_family_data()->internal_comparator();
const std::vector<FileMetaData*>& grandparents = compaction->grandparents();
// Scan to find earliest grandparent file that contains key.
while (grandparent_index < grandparents.size() &&
icmp->Compare(internal_key,
grandparents[grandparent_index]->largest.Encode()) >
0) {
if (seen_key) {
overlapped_bytes += grandparents[grandparent_index]->fd.GetFileSize();
}
assert(grandparent_index + 1 >= grandparents.size() ||
icmp->Compare(
grandparents[grandparent_index]->largest.Encode(),
grandparents[grandparent_index + 1]->smallest.Encode()) <= 0);
grandparent_index++;
}
seen_key = true;
if (overlapped_bytes + curr_file_size >
compaction->max_compaction_bytes()) {
// Too much overlap for current output; start new output
overlapped_bytes = 0;
return true;
}
return false;
}
};
// Maintains state for the entire compaction
struct CompactionJob::CompactionState {
Compaction* const compaction;
// REQUIRED: subcompaction states are stored in order of increasing
// key-range
std::vector<CompactionJob::SubcompactionState> sub_compact_states;
Status status;
uint64_t total_bytes;
uint64_t num_input_records;
uint64_t num_output_records;
explicit CompactionState(Compaction* c)
: compaction(c),
total_bytes(0),
num_input_records(0),
num_output_records(0) {}
size_t NumOutputFiles() {
size_t total = 0;
for (auto& s : sub_compact_states) {
total += s.outputs.size();
}
return total;
}
Slice SmallestUserKey() {
for (const auto& sub_compact_state : sub_compact_states) {
if (!sub_compact_state.outputs.empty() &&
sub_compact_state.outputs[0].finished) {
return sub_compact_state.outputs[0].meta.smallest.user_key();
}
}
// If there is no finished output, return an empty slice.
return Slice(nullptr, 0);
}
Slice LargestUserKey() {
for (auto it = sub_compact_states.rbegin(); it < sub_compact_states.rend();
++it) {
if (!it->outputs.empty() && it->current_output()->finished) {
assert(it->current_output() != nullptr);
return it->current_output()->meta.largest.user_key();
}
}
// If there is no finished output, return an empty slice.
return Slice(nullptr, 0);
}
};
void CompactionJob::AggregateStatistics() {
for (SubcompactionState& sc : compact_->sub_compact_states) {
compact_->total_bytes += sc.total_bytes;
compact_->num_input_records += sc.num_input_records;
compact_->num_output_records += sc.num_output_records;
}
if (compaction_job_stats_) {
for (SubcompactionState& sc : compact_->sub_compact_states) {
compaction_job_stats_->Add(sc.compaction_job_stats);
}
}
}
CompactionJob::CompactionJob(
int job_id, Compaction* compaction, const ImmutableDBOptions& db_options,
const EnvOptions env_options, VersionSet* versions,
const std::atomic<bool>* shutting_down,
const SequenceNumber preserve_deletes_seqnum, LogBuffer* log_buffer,
Directory* db_directory, Directory* output_directory, Statistics* stats,
InstrumentedMutex* db_mutex, ErrorHandler* db_error_handler,
std::vector<SequenceNumber> existing_snapshots,
SequenceNumber earliest_write_conflict_snapshot,
const SnapshotChecker* snapshot_checker, std::shared_ptr<Cache> table_cache,
EventLogger* event_logger, bool paranoid_file_checks, bool measure_io_stats,
const std::string& dbname, CompactionJobStats* compaction_job_stats)
: job_id_(job_id),
compact_(new CompactionState(compaction)),
compaction_job_stats_(compaction_job_stats),
compaction_stats_(compaction->compaction_reason(), 1),
dbname_(dbname),
db_options_(db_options),
env_options_(env_options),
env_(db_options.env),
env_optiosn_for_read_(
env_->OptimizeForCompactionTableRead(env_options, db_options_)),
versions_(versions),
shutting_down_(shutting_down),
preserve_deletes_seqnum_(preserve_deletes_seqnum),
log_buffer_(log_buffer),
db_directory_(db_directory),
output_directory_(output_directory),
stats_(stats),
db_mutex_(db_mutex),
db_error_handler_(db_error_handler),
existing_snapshots_(std::move(existing_snapshots)),
earliest_write_conflict_snapshot_(earliest_write_conflict_snapshot),
snapshot_checker_(snapshot_checker),
table_cache_(std::move(table_cache)),
event_logger_(event_logger),
bottommost_level_(false),
paranoid_file_checks_(paranoid_file_checks),
measure_io_stats_(measure_io_stats),
write_hint_(Env::WLTH_NOT_SET) {
assert(log_buffer_ != nullptr);
const auto* cfd = compact_->compaction->column_family_data();
ThreadStatusUtil::SetColumnFamily(cfd, cfd->ioptions()->env,
db_options_.enable_thread_tracking);
ThreadStatusUtil::SetThreadOperation(ThreadStatus::OP_COMPACTION);
ReportStartedCompaction(compaction);
}
CompactionJob::~CompactionJob() {
assert(compact_ == nullptr);
ThreadStatusUtil::ResetThreadStatus();
}
void CompactionJob::ReportStartedCompaction(Compaction* compaction) {
const auto* cfd = compact_->compaction->column_family_data();
ThreadStatusUtil::SetColumnFamily(cfd, cfd->ioptions()->env,
db_options_.enable_thread_tracking);
ThreadStatusUtil::SetThreadOperationProperty(ThreadStatus::COMPACTION_JOB_ID,
job_id_);
ThreadStatusUtil::SetThreadOperationProperty(
ThreadStatus::COMPACTION_INPUT_OUTPUT_LEVEL,
(static_cast<uint64_t>(compact_->compaction->start_level()) << 32) +
compact_->compaction->output_level());
// In the current design, a CompactionJob is always created
// for non-trivial compaction.
assert(compaction->IsTrivialMove() == false ||
compaction->is_manual_compaction() == true);
ThreadStatusUtil::SetThreadOperationProperty(
ThreadStatus::COMPACTION_PROP_FLAGS,
compaction->is_manual_compaction() +
(compaction->deletion_compaction() << 1));
ThreadStatusUtil::SetThreadOperationProperty(
ThreadStatus::COMPACTION_TOTAL_INPUT_BYTES,
compaction->CalculateTotalInputSize());
IOSTATS_RESET(bytes_written);
IOSTATS_RESET(bytes_read);
ThreadStatusUtil::SetThreadOperationProperty(
ThreadStatus::COMPACTION_BYTES_WRITTEN, 0);
ThreadStatusUtil::SetThreadOperationProperty(
ThreadStatus::COMPACTION_BYTES_READ, 0);
// Set the thread operation after operation properties
// to ensure GetThreadList() can always show them all together.
ThreadStatusUtil::SetThreadOperation(ThreadStatus::OP_COMPACTION);
if (compaction_job_stats_) {
compaction_job_stats_->is_manual_compaction =
compaction->is_manual_compaction();
}
}
void CompactionJob::Prepare() {
AutoThreadOperationStageUpdater stage_updater(
ThreadStatus::STAGE_COMPACTION_PREPARE);
// Generate file_levels_ for compaction berfore making Iterator
auto* c = compact_->compaction;
assert(c->column_family_data() != nullptr);
assert(c->column_family_data()->current()->storage_info()->NumLevelFiles(
compact_->compaction->level()) > 0);
write_hint_ =
c->column_family_data()->CalculateSSTWriteHint(c->output_level());
// Is this compaction producing files at the bottommost level?
bottommost_level_ = c->bottommost_level();
if (c->ShouldFormSubcompactions()) {
const uint64_t start_micros = env_->NowMicros();
GenSubcompactionBoundaries();
MeasureTime(stats_, SUBCOMPACTION_SETUP_TIME,
env_->NowMicros() - start_micros);
assert(sizes_.size() == boundaries_.size() + 1);
for (size_t i = 0; i <= boundaries_.size(); i++) {
Slice* start = i == 0 ? nullptr : &boundaries_[i - 1];
Slice* end = i == boundaries_.size() ? nullptr : &boundaries_[i];
compact_->sub_compact_states.emplace_back(c, start, end, sizes_[i]);
}
MeasureTime(stats_, NUM_SUBCOMPACTIONS_SCHEDULED,
compact_->sub_compact_states.size());
} else {
compact_->sub_compact_states.emplace_back(c, nullptr, nullptr);
}
}
struct RangeWithSize {
Range range;
uint64_t size;
RangeWithSize(const Slice& a, const Slice& b, uint64_t s = 0)
: range(a, b), size(s) {}
};
// Generates a histogram representing potential divisions of key ranges from
// the input. It adds the starting and/or ending keys of certain input files
// to the working set and then finds the approximate size of data in between
// each consecutive pair of slices. Then it divides these ranges into
// consecutive groups such that each group has a similar size.
void CompactionJob::GenSubcompactionBoundaries() {
auto* c = compact_->compaction;
auto* cfd = c->column_family_data();
const Comparator* cfd_comparator = cfd->user_comparator();
std::vector<Slice> bounds;
int start_lvl = c->start_level();
int out_lvl = c->output_level();
// Add the starting and/or ending key of certain input files as a potential
// boundary
for (size_t lvl_idx = 0; lvl_idx < c->num_input_levels(); lvl_idx++) {
int lvl = c->level(lvl_idx);
if (lvl >= start_lvl && lvl <= out_lvl) {
const LevelFilesBrief* flevel = c->input_levels(lvl_idx);
size_t num_files = flevel->num_files;
if (num_files == 0) {
continue;
}
if (lvl == 0) {
// For level 0 add the starting and ending key of each file since the
// files may have greatly differing key ranges (not range-partitioned)
for (size_t i = 0; i < num_files; i++) {
bounds.emplace_back(flevel->files[i].smallest_key);
bounds.emplace_back(flevel->files[i].largest_key);
}
} else {
// For all other levels add the smallest/largest key in the level to
// encompass the range covered by that level
bounds.emplace_back(flevel->files[0].smallest_key);
bounds.emplace_back(flevel->files[num_files - 1].largest_key);
if (lvl == out_lvl) {
// For the last level include the starting keys of all files since
// the last level is the largest and probably has the widest key
// range. Since it's range partitioned, the ending key of one file
// and the starting key of the next are very close (or identical).
for (size_t i = 1; i < num_files; i++) {
bounds.emplace_back(flevel->files[i].smallest_key);
}
}
}
}
}
std::sort(bounds.begin(), bounds.end(),
[cfd_comparator](const Slice& a, const Slice& b) -> bool {
return cfd_comparator->Compare(ExtractUserKey(a),
ExtractUserKey(b)) < 0;
});
// Remove duplicated entries from bounds
bounds.erase(
std::unique(bounds.begin(), bounds.end(),
[cfd_comparator](const Slice& a, const Slice& b) -> bool {
return cfd_comparator->Compare(ExtractUserKey(a),
ExtractUserKey(b)) == 0;
}),
bounds.end());
// Combine consecutive pairs of boundaries into ranges with an approximate
// size of data covered by keys in that range
uint64_t sum = 0;
std::vector<RangeWithSize> ranges;
// Get input version from CompactionState since it's already referenced
// earlier in SetInputVersioCompaction::SetInputVersion and will not change
// when db_mutex_ is released below
auto* v = compact_->compaction->input_version();
for (auto it = bounds.begin();;) {
const Slice a = *it;
it++;
if (it == bounds.end()) {
break;
}
const Slice b = *it;
// ApproximateSize could potentially create table reader iterator to seek
// to the index block and may incur I/O cost in the process. Unlock db
// mutex to reduce contention
db_mutex_->Unlock();
uint64_t size = versions_->ApproximateSize(v, a, b, start_lvl, out_lvl + 1);
db_mutex_->Lock();
ranges.emplace_back(a, b, size);
sum += size;
}
// Group the ranges into subcompactions
const double min_file_fill_percent = 4.0 / 5;
int base_level = v->storage_info()->base_level();
uint64_t max_output_files = static_cast<uint64_t>(std::ceil(
sum / min_file_fill_percent /
MaxFileSizeForLevel(*(c->mutable_cf_options()), out_lvl,
c->immutable_cf_options()->compaction_style, base_level,
c->immutable_cf_options()->level_compaction_dynamic_level_bytes)));
uint64_t subcompactions =
std::min({static_cast<uint64_t>(ranges.size()),
static_cast<uint64_t>(c->max_subcompactions()),
max_output_files});
if (subcompactions > 1) {
double mean = sum * 1.0 / subcompactions;
// Greedily add ranges to the subcompaction until the sum of the ranges'
// sizes becomes >= the expected mean size of a subcompaction
sum = 0;
for (size_t i = 0; i < ranges.size() - 1; i++) {
sum += ranges[i].size;
if (subcompactions == 1) {
// If there's only one left to schedule then it goes to the end so no
// need to put an end boundary
continue;
}
if (sum >= mean) {
boundaries_.emplace_back(ExtractUserKey(ranges[i].range.limit));
sizes_.emplace_back(sum);
subcompactions--;
sum = 0;
}
}
sizes_.emplace_back(sum + ranges.back().size);
} else {
// Only one range so its size is the total sum of sizes computed above
sizes_.emplace_back(sum);
}
}
Status CompactionJob::Run() {
AutoThreadOperationStageUpdater stage_updater(
ThreadStatus::STAGE_COMPACTION_RUN);
TEST_SYNC_POINT("CompactionJob::Run():Start");
log_buffer_->FlushBufferToLog();
LogCompaction();
const size_t num_threads = compact_->sub_compact_states.size();
assert(num_threads > 0);
const uint64_t start_micros = env_->NowMicros();
// Launch a thread for each of subcompactions 1...num_threads-1
std::vector<port::Thread> thread_pool;
thread_pool.reserve(num_threads - 1);
for (size_t i = 1; i < compact_->sub_compact_states.size(); i++) {
thread_pool.emplace_back(&CompactionJob::ProcessKeyValueCompaction, this,
&compact_->sub_compact_states[i]);
}
// Always schedule the first subcompaction (whether or not there are also
// others) in the current thread to be efficient with resources
ProcessKeyValueCompaction(&compact_->sub_compact_states[0]);
// Wait for all other threads (if there are any) to finish execution
for (auto& thread : thread_pool) {
thread.join();
}
compaction_stats_.micros = env_->NowMicros() - start_micros;
MeasureTime(stats_, COMPACTION_TIME, compaction_stats_.micros);
TEST_SYNC_POINT("CompactionJob::Run:BeforeVerify");
// Check if any thread encountered an error during execution
Status status;
for (const auto& state : compact_->sub_compact_states) {
if (!state.status.ok()) {
status = state.status;
break;
}
}
if (status.ok() && output_directory_) {
status = output_directory_->Fsync();
}
if (status.ok()) {
thread_pool.clear();
std::vector<const FileMetaData*> files_meta;
for (const auto& state : compact_->sub_compact_states) {
for (const auto& output : state.outputs) {
files_meta.emplace_back(&output.meta);
}
}
ColumnFamilyData* cfd = compact_->compaction->column_family_data();
auto prefix_extractor =
compact_->compaction->mutable_cf_options()->prefix_extractor.get();
std::atomic<size_t> next_file_meta_idx(0);
auto verify_table = [&](Status& output_status) {
while (true) {
size_t file_idx = next_file_meta_idx.fetch_add(1);
if (file_idx >= files_meta.size()) {
break;
}
// Verify that the table is usable
// We set for_compaction to false and don't OptimizeForCompactionTableRead
// here because this is a special case after we finish the table building
// No matter whether use_direct_io_for_flush_and_compaction is true,
// we will regard this verification as user reads since the goal is
// to cache it here for further user reads
InternalIterator* iter = cfd->table_cache()->NewIterator(
ReadOptions(), env_options_, cfd->internal_comparator(),
*files_meta[file_idx], nullptr /* range_del_agg */,
prefix_extractor, nullptr,
cfd->internal_stats()->GetFileReadHist(
compact_->compaction->output_level()),
false, nullptr /* arena */, false /* skip_filters */,
compact_->compaction->output_level());
auto s = iter->status();
if (s.ok() && paranoid_file_checks_) {
for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {}
s = iter->status();
}
delete iter;
if (!s.ok()) {
output_status = s;
break;
}
}
};
for (size_t i = 1; i < compact_->sub_compact_states.size(); i++) {
thread_pool.emplace_back(verify_table,
std::ref(compact_->sub_compact_states[i].status));
}
verify_table(compact_->sub_compact_states[0].status);
for (auto& thread : thread_pool) {
thread.join();
}
for (const auto& state : compact_->sub_compact_states) {
if (!state.status.ok()) {
status = state.status;
break;
}
}
}
TablePropertiesCollection tp;
for (const auto& state : compact_->sub_compact_states) {
for (const auto& output : state.outputs) {
auto fn =
TableFileName(state.compaction->immutable_cf_options()->cf_paths,
output.meta.fd.GetNumber(), output.meta.fd.GetPathId());
tp[fn] = output.table_properties;
}
}
compact_->compaction->SetOutputTableProperties(std::move(tp));
// Finish up all book-keeping to unify the subcompaction results
AggregateStatistics();
UpdateCompactionStats();
RecordCompactionIOStats();
LogFlush(db_options_.info_log);
TEST_SYNC_POINT("CompactionJob::Run():End");
compact_->status = status;
return status;
}
Status CompactionJob::Install(const MutableCFOptions& mutable_cf_options) {
AutoThreadOperationStageUpdater stage_updater(
ThreadStatus::STAGE_COMPACTION_INSTALL);
db_mutex_->AssertHeld();
Status status = compact_->status;
ColumnFamilyData* cfd = compact_->compaction->column_family_data();
cfd->internal_stats()->AddCompactionStats(
compact_->compaction->output_level(), compaction_stats_);
if (status.ok()) {
status = InstallCompactionResults(mutable_cf_options);
}
VersionStorageInfo::LevelSummaryStorage tmp;
auto vstorage = cfd->current()->storage_info();
const auto& stats = compaction_stats_;
double read_write_amp = 0.0;
double write_amp = 0.0;
double bytes_read_per_sec = 0;
double bytes_written_per_sec = 0;
if (stats.bytes_read_non_output_levels > 0) {
read_write_amp = (stats.bytes_written + stats.bytes_read_output_level +
stats.bytes_read_non_output_levels) /
static_cast<double>(stats.bytes_read_non_output_levels);
write_amp = stats.bytes_written /
static_cast<double>(stats.bytes_read_non_output_levels);
}
if (stats.micros > 0) {
bytes_read_per_sec =
(stats.bytes_read_non_output_levels + stats.bytes_read_output_level) /
static_cast<double>(stats.micros);
bytes_written_per_sec =
stats.bytes_written / static_cast<double>(stats.micros);
}
ROCKS_LOG_BUFFER(
log_buffer_,
"[%s] compacted to: %s, MB/sec: %.1f rd, %.1f wr, level %d, "
"files in(%d, %d) out(%d) "
"MB in(%.1f, %.1f) out(%.1f), read-write-amplify(%.1f) "
"write-amplify(%.1f) %s, records in: %" PRIu64
", records dropped: %" PRIu64 " output_compression: %s\n",
cfd->GetName().c_str(), vstorage->LevelSummary(&tmp), bytes_read_per_sec,
bytes_written_per_sec, compact_->compaction->output_level(),
stats.num_input_files_in_non_output_levels,
stats.num_input_files_in_output_level, stats.num_output_files,
stats.bytes_read_non_output_levels / 1048576.0,
stats.bytes_read_output_level / 1048576.0,
stats.bytes_written / 1048576.0, read_write_amp, write_amp,
status.ToString().c_str(), stats.num_input_records,
stats.num_dropped_records,
CompressionTypeToString(compact_->compaction->output_compression())
.c_str());
UpdateCompactionJobStats(stats);
auto stream = event_logger_->LogToBuffer(log_buffer_);
stream << "job" << job_id_ << "event"
<< "compaction_finished"
<< "compaction_time_micros" << compaction_stats_.micros
<< "output_level" << compact_->compaction->output_level()
<< "num_output_files" << compact_->NumOutputFiles()
<< "total_output_size" << compact_->total_bytes << "num_input_records"
<< compact_->num_input_records << "num_output_records"
<< compact_->num_output_records << "num_subcompactions"
<< compact_->sub_compact_states.size() << "output_compression"
<< CompressionTypeToString(compact_->compaction->output_compression());
if (compaction_job_stats_ != nullptr) {
stream << "num_single_delete_mismatches"
<< compaction_job_stats_->num_single_del_mismatch;
stream << "num_single_delete_fallthrough"
<< compaction_job_stats_->num_single_del_fallthru;
}
if (measure_io_stats_ && compaction_job_stats_ != nullptr) {
stream << "file_write_nanos" << compaction_job_stats_->file_write_nanos;
stream << "file_range_sync_nanos"
<< compaction_job_stats_->file_range_sync_nanos;
stream << "file_fsync_nanos" << compaction_job_stats_->file_fsync_nanos;
stream << "file_prepare_write_nanos"
<< compaction_job_stats_->file_prepare_write_nanos;
}
stream << "lsm_state";
stream.StartArray();
for (int level = 0; level < vstorage->num_levels(); ++level) {
stream << vstorage->NumLevelFiles(level);
}
stream.EndArray();
CleanupCompaction();
return status;
}
void CompactionJob::ProcessKeyValueCompaction(SubcompactionState* sub_compact) {
assert(sub_compact != nullptr);
ColumnFamilyData* cfd = sub_compact->compaction->column_family_data();
RangeDelAggregatorV2 range_del_agg_v2(&cfd->internal_comparator(),
kMaxSequenceNumber /* upper_bound */);
auto* range_del_agg =
range_del_agg_v2.DelegateToRangeDelAggregator(existing_snapshots_);
// Although the v2 aggregator is what the level iterator(s) know about,
// the AddTombstones calls will be propagated down to the v1 aggregator.
std::unique_ptr<InternalIterator> input(versions_->MakeInputIterator(
sub_compact->compaction, &range_del_agg_v2, env_optiosn_for_read_));
AutoThreadOperationStageUpdater stage_updater(
ThreadStatus::STAGE_COMPACTION_PROCESS_KV);
// I/O measurement variables
PerfLevel prev_perf_level = PerfLevel::kEnableTime;
const uint64_t kRecordStatsEvery = 1000;
uint64_t prev_write_nanos = 0;
uint64_t prev_fsync_nanos = 0;
uint64_t prev_range_sync_nanos = 0;
uint64_t prev_prepare_write_nanos = 0;
if (measure_io_stats_) {
prev_perf_level = GetPerfLevel();
SetPerfLevel(PerfLevel::kEnableTime);
prev_write_nanos = IOSTATS(write_nanos);
prev_fsync_nanos = IOSTATS(fsync_nanos);
prev_range_sync_nanos = IOSTATS(range_sync_nanos);
prev_prepare_write_nanos = IOSTATS(prepare_write_nanos);
}
const MutableCFOptions* mutable_cf_options =
sub_compact->compaction->mutable_cf_options();
// To build compression dictionary, we sample the first output file, assuming
// it'll reach the maximum length. We optionally pass these samples through
// zstd's dictionary trainer, or just use them directly. Then, the dictionary
// is used for compressing subsequent output files in the same subcompaction.
const bool kUseZstdTrainer =
sub_compact->compaction->output_compression_opts().zstd_max_train_bytes >
0;
const size_t kSampleBytes =
kUseZstdTrainer
? sub_compact->compaction->output_compression_opts()
.zstd_max_train_bytes
: sub_compact->compaction->output_compression_opts().max_dict_bytes;
const int kSampleLenShift = 6; // 2^6 = 64-byte samples
std::set<size_t> sample_begin_offsets;
if (bottommost_level_ && kSampleBytes > 0) {
const size_t kMaxSamples = kSampleBytes >> kSampleLenShift;
const size_t kOutFileLen =
static_cast<size_t>(MaxFileSizeForLevel(*mutable_cf_options,
compact_->compaction->output_level(),
cfd->ioptions()->compaction_style,
compact_->compaction->GetInputBaseLevel(),
cfd->ioptions()->level_compaction_dynamic_level_bytes));
if (kOutFileLen != port::kMaxSizet) {
const size_t kOutFileNumSamples = kOutFileLen >> kSampleLenShift;
Random64 generator{versions_->NewFileNumber()};
for (size_t i = 0; i < kMaxSamples; ++i) {
sample_begin_offsets.insert(
static_cast<size_t>(generator.Uniform(kOutFileNumSamples))
<< kSampleLenShift);
}
}
}
auto compaction_filter = cfd->ioptions()->compaction_filter;
std::unique_ptr<CompactionFilter> compaction_filter_from_factory = nullptr;
if (compaction_filter == nullptr) {
compaction_filter_from_factory =
sub_compact->compaction->CreateCompactionFilter();
compaction_filter = compaction_filter_from_factory.get();
}
MergeHelper merge(
env_, cfd->user_comparator(), cfd->ioptions()->merge_operator,
compaction_filter, db_options_.info_log.get(),
false /* internal key corruption is expected */,
existing_snapshots_.empty() ? 0 : existing_snapshots_.back(),
snapshot_checker_, compact_->compaction->level(),
db_options_.statistics.get(), shutting_down_);
TEST_SYNC_POINT("CompactionJob::Run():Inprogress");
Slice* start = sub_compact->start;
Slice* end = sub_compact->end;
if (start != nullptr) {
IterKey start_iter;
start_iter.SetInternalKey(*start, kMaxSequenceNumber, kValueTypeForSeek);
input->Seek(start_iter.GetInternalKey());
} else {
input->SeekToFirst();
}
Status status;
sub_compact->c_iter.reset(new CompactionIterator(
input.get(), cfd->user_comparator(), &merge, versions_->LastSequence(),
&existing_snapshots_, earliest_write_conflict_snapshot_,
snapshot_checker_, env_, ShouldReportDetailedTime(env_, stats_), false,
range_del_agg, sub_compact->compaction, compaction_filter, shutting_down_,
preserve_deletes_seqnum_));
auto c_iter = sub_compact->c_iter.get();
c_iter->SeekToFirst();
if (c_iter->Valid() && sub_compact->compaction->output_level() != 0) {
// ShouldStopBefore() maintains state based on keys processed so far. The
// compaction loop always calls it on the "next" key, thus won't tell it the
// first key. So we do that here.
sub_compact->ShouldStopBefore(c_iter->key(),
sub_compact->current_output_file_size);
}
const auto& c_iter_stats = c_iter->iter_stats();
auto sample_begin_offset_iter = sample_begin_offsets.cbegin();
// data_begin_offset and dict_sample_data are only valid while generating
// dictionary from the first output file.
size_t data_begin_offset = 0;
std::string dict_sample_data;
dict_sample_data.reserve(kSampleBytes);
while (status.ok() && !cfd->IsDropped() && c_iter->Valid()) {
// Invariant: c_iter.status() is guaranteed to be OK if c_iter->Valid()
// returns true.
const Slice& key = c_iter->key();
const Slice& value = c_iter->value();
// If an end key (exclusive) is specified, check if the current key is
// >= than it and exit if it is because the iterator is out of its range
if (end != nullptr &&
cfd->user_comparator()->Compare(c_iter->user_key(), *end) >= 0) {
break;
}
if (c_iter_stats.num_input_records % kRecordStatsEvery ==
kRecordStatsEvery - 1) {
RecordDroppedKeys(c_iter_stats, &sub_compact->compaction_job_stats);
c_iter->ResetRecordCounts();
RecordCompactionIOStats();
}
// Open output file if necessary
if (sub_compact->builder == nullptr) {
status = OpenCompactionOutputFile(sub_compact);
if (!status.ok()) {
break;
}
}
assert(sub_compact->builder != nullptr);
assert(sub_compact->current_output() != nullptr);
sub_compact->builder->Add(key, value);
sub_compact->current_output_file_size = sub_compact->builder->FileSize();
sub_compact->current_output()->meta.UpdateBoundaries(
key, c_iter->ikey().sequence);
sub_compact->num_output_records++;
if (sub_compact->outputs.size() == 1) { // first output file
// Check if this key/value overlaps any sample intervals; if so, appends
// overlapping portions to the dictionary.
for (const auto& data_elmt : {key, value}) {
size_t data_end_offset = data_begin_offset + data_elmt.size();
while (sample_begin_offset_iter != sample_begin_offsets.cend() &&
*sample_begin_offset_iter < data_end_offset) {
size_t sample_end_offset =
*sample_begin_offset_iter + (1 << kSampleLenShift);
// Invariant: Because we advance sample iterator while processing the
// data_elmt containing the sample's last byte, the current sample
// cannot end before the current data_elmt.
assert(data_begin_offset < sample_end_offset);
size_t data_elmt_copy_offset, data_elmt_copy_len;
if (*sample_begin_offset_iter <= data_begin_offset) {
// The sample starts before data_elmt starts, so take bytes starting
// at the beginning of data_elmt.
data_elmt_copy_offset = 0;
} else {
// data_elmt starts before the sample starts, so take bytes starting
// at the below offset into data_elmt.
data_elmt_copy_offset =
*sample_begin_offset_iter - data_begin_offset;
}
if (sample_end_offset <= data_end_offset) {
// The sample ends before data_elmt ends, so take as many bytes as
// needed.
data_elmt_copy_len =
sample_end_offset - (data_begin_offset + data_elmt_copy_offset);
} else {
// data_elmt ends before the sample ends, so take all remaining
// bytes in data_elmt.
data_elmt_copy_len =
data_end_offset - (data_begin_offset + data_elmt_copy_offset);
}
dict_sample_data.append(&data_elmt.data()[data_elmt_copy_offset],
data_elmt_copy_len);
if (sample_end_offset > data_end_offset) {
// Didn't finish sample. Try to finish it with the next data_elmt.
break;
}
// Next sample may require bytes from same data_elmt.
sample_begin_offset_iter++;
}
data_begin_offset = data_end_offset;
}
}
// Close output file if it is big enough. Two possibilities determine it's
// time to close it: (1) the current key should be this file's last key, (2)
// the next key should not be in this file.
//
// TODO(aekmekji): determine if file should be closed earlier than this
// during subcompactions (i.e. if output size, estimated by input size, is
// going to be 1.2MB and max_output_file_size = 1MB, prefer to have 0.6MB
// and 0.6MB instead of 1MB and 0.2MB)
bool output_file_ended = false;
Status input_status;
if (sub_compact->compaction->output_level() != 0 &&
sub_compact->current_output_file_size >=
sub_compact->compaction->max_output_file_size()) {
// (1) this key terminates the file. For historical reasons, the iterator
// status before advancing will be given to FinishCompactionOutputFile().
input_status = input->status();
output_file_ended = true;
}
c_iter->Next();
if (!output_file_ended && c_iter->Valid() &&
sub_compact->compaction->output_level() != 0 &&
sub_compact->ShouldStopBefore(c_iter->key(),
sub_compact->current_output_file_size) &&
sub_compact->builder != nullptr) {
// (2) this key belongs to the next file. For historical reasons, the
// iterator status after advancing will be given to
// FinishCompactionOutputFile().
input_status = input->status();
output_file_ended = true;
}
if (output_file_ended) {
const Slice* next_key = nullptr;
if (c_iter->Valid()) {
next_key = &c_iter->key();
}
CompactionIterationStats range_del_out_stats;
status =
FinishCompactionOutputFile(input_status, sub_compact, range_del_agg,
&range_del_out_stats, next_key);
RecordDroppedKeys(range_del_out_stats,
&sub_compact->compaction_job_stats);
if (sub_compact->outputs.size() == 1) {
// Use samples from first output file to create dictionary for
// compression of subsequent files.
if (kUseZstdTrainer) {
sub_compact->compression_dict = ZSTD_TrainDictionary(
dict_sample_data, kSampleLenShift,
sub_compact->compaction->output_compression_opts()
.max_dict_bytes);
} else {
sub_compact->compression_dict = std::move(dict_sample_data);
}
}
}
}
sub_compact->num_input_records = c_iter_stats.num_input_records;
sub_compact->compaction_job_stats.num_input_deletion_records =
c_iter_stats.num_input_deletion_records;
sub_compact->compaction_job_stats.num_corrupt_keys =
c_iter_stats.num_input_corrupt_records;
sub_compact->compaction_job_stats.num_single_del_fallthru =
c_iter_stats.num_single_del_fallthru;
sub_compact->compaction_job_stats.num_single_del_mismatch =
c_iter_stats.num_single_del_mismatch;
sub_compact->compaction_job_stats.total_input_raw_key_bytes +=
c_iter_stats.total_input_raw_key_bytes;
sub_compact->compaction_job_stats.total_input_raw_value_bytes +=
c_iter_stats.total_input_raw_value_bytes;
RecordTick(stats_, FILTER_OPERATION_TOTAL_TIME,
c_iter_stats.total_filter_time);
RecordDroppedKeys(c_iter_stats, &sub_compact->compaction_job_stats);
RecordCompactionIOStats();
if (status.ok() &&
(shutting_down_->load(std::memory_order_relaxed) || cfd->IsDropped())) {
status = Status::ShutdownInProgress(
"Database shutdown or Column family drop during compaction");
}
if (status.ok()) {
status = input->status();
}
if (status.ok()) {
status = c_iter->status();
}
if (status.ok() && sub_compact->builder == nullptr &&
sub_compact->outputs.size() == 0 &&
!range_del_agg->IsEmpty()) {
// handle subcompaction containing only range deletions
status = OpenCompactionOutputFile(sub_compact);
}
// Call FinishCompactionOutputFile() even if status is not ok: it needs to
// close the output file.
if (sub_compact->builder != nullptr) {
CompactionIterationStats range_del_out_stats;
Status s = FinishCompactionOutputFile(status, sub_compact, range_del_agg,
&range_del_out_stats);
if (status.ok()) {
status = s;
}
RecordDroppedKeys(range_del_out_stats, &sub_compact->compaction_job_stats);
}
if (measure_io_stats_) {
sub_compact->compaction_job_stats.file_write_nanos +=
IOSTATS(write_nanos) - prev_write_nanos;
sub_compact->compaction_job_stats.file_fsync_nanos +=
IOSTATS(fsync_nanos) - prev_fsync_nanos;
sub_compact->compaction_job_stats.file_range_sync_nanos +=
IOSTATS(range_sync_nanos) - prev_range_sync_nanos;
sub_compact->compaction_job_stats.file_prepare_write_nanos +=
IOSTATS(prepare_write_nanos) - prev_prepare_write_nanos;
if (prev_perf_level != PerfLevel::kEnableTime) {
SetPerfLevel(prev_perf_level);
}
}
sub_compact->c_iter.reset();
input.reset();
sub_compact->status = status;
}
void CompactionJob::RecordDroppedKeys(
const CompactionIterationStats& c_iter_stats,
CompactionJobStats* compaction_job_stats) {
if (c_iter_stats.num_record_drop_user > 0) {
RecordTick(stats_, COMPACTION_KEY_DROP_USER,
c_iter_stats.num_record_drop_user);
}
if (c_iter_stats.num_record_drop_hidden > 0) {
RecordTick(stats_, COMPACTION_KEY_DROP_NEWER_ENTRY,
c_iter_stats.num_record_drop_hidden);
if (compaction_job_stats) {
compaction_job_stats->num_records_replaced +=
c_iter_stats.num_record_drop_hidden;
}
}
if (c_iter_stats.num_record_drop_obsolete > 0) {
RecordTick(stats_, COMPACTION_KEY_DROP_OBSOLETE,
c_iter_stats.num_record_drop_obsolete);
if (compaction_job_stats) {
compaction_job_stats->num_expired_deletion_records +=
c_iter_stats.num_record_drop_obsolete;
}
}
if (c_iter_stats.num_record_drop_range_del > 0) {
RecordTick(stats_, COMPACTION_KEY_DROP_RANGE_DEL,
c_iter_stats.num_record_drop_range_del);
}
if (c_iter_stats.num_range_del_drop_obsolete > 0) {
RecordTick(stats_, COMPACTION_RANGE_DEL_DROP_OBSOLETE,
c_iter_stats.num_range_del_drop_obsolete);
}
if (c_iter_stats.num_optimized_del_drop_obsolete > 0) {
RecordTick(stats_, COMPACTION_OPTIMIZED_DEL_DROP_OBSOLETE,
c_iter_stats.num_optimized_del_drop_obsolete);
}
}
Status CompactionJob::FinishCompactionOutputFile(
const Status& input_status, SubcompactionState* sub_compact,
RangeDelAggregator* range_del_agg,
CompactionIterationStats* range_del_out_stats,
const Slice* next_table_min_key /* = nullptr */) {
AutoThreadOperationStageUpdater stage_updater(
ThreadStatus::STAGE_COMPACTION_SYNC_FILE);
assert(sub_compact != nullptr);
assert(sub_compact->outfile);
assert(sub_compact->builder != nullptr);
assert(sub_compact->current_output() != nullptr);
uint64_t output_number = sub_compact->current_output()->meta.fd.GetNumber();
assert(output_number != 0);
ColumnFamilyData* cfd = sub_compact->compaction->column_family_data();
const Comparator* ucmp = cfd->user_comparator();
// Check for iterator errors
Status s = input_status;
auto meta = &sub_compact->current_output()->meta;
assert(meta != nullptr);
if (s.ok()) {
Slice lower_bound_guard, upper_bound_guard;
std::string smallest_user_key;
const Slice *lower_bound, *upper_bound;
bool lower_bound_from_sub_compact = false;
if (sub_compact->outputs.size() == 1) {
// For the first output table, include range tombstones before the min key
// but after the subcompaction boundary.
lower_bound = sub_compact->start;
lower_bound_from_sub_compact = true;
} else if (meta->smallest.size() > 0) {
// For subsequent output tables, only include range tombstones from min
// key onwards since the previous file was extended to contain range
// tombstones falling before min key.
smallest_user_key = meta->smallest.user_key().ToString(false /*hex*/);
lower_bound_guard = Slice(smallest_user_key);
lower_bound = &lower_bound_guard;
} else {
lower_bound = nullptr;
}
if (next_table_min_key != nullptr) {
// This isn't the last file in the subcompaction, so extend until the next
// file starts.
upper_bound_guard = ExtractUserKey(*next_table_min_key);
upper_bound = &upper_bound_guard;
} else {
// This is the last file in the subcompaction, so extend until the
// subcompaction ends.
upper_bound = sub_compact->end;
}
auto earliest_snapshot = kMaxSequenceNumber;
if (existing_snapshots_.size() > 0) {
earliest_snapshot = existing_snapshots_[0];
}
auto it = range_del_agg->NewIterator();
if (lower_bound != nullptr) {
it->Seek(*lower_bound);
}
bool has_overlapping_endpoints;
if (upper_bound != nullptr && meta->largest.size() > 0) {
has_overlapping_endpoints =
ucmp->Compare(meta->largest.user_key(), *upper_bound) == 0;
} else {
has_overlapping_endpoints = false;
}
for (; it->Valid(); it->Next()) {
auto tombstone = it->Tombstone();
if (upper_bound != nullptr) {
int cmp = ucmp->Compare(*upper_bound, tombstone.start_key_);
if ((has_overlapping_endpoints && cmp < 0) ||
(!has_overlapping_endpoints && cmp <= 0)) {
// Tombstones starting after upper_bound only need to be included in
// the next table. If the current SST ends before upper_bound, i.e.,
// `has_overlapping_endpoints == false`, we can also skip over range
// tombstones that start exactly at upper_bound. Such range tombstones
// will be included in the next file and are not relevant to the point
// keys or endpoints of the current file.
break;
}
}
if (bottommost_level_ && tombstone.seq_ <= earliest_snapshot) {
// TODO(andrewkr): tombstones that span multiple output files are
// counted for each compaction output file, so lots of double counting.
range_del_out_stats->num_range_del_drop_obsolete++;
range_del_out_stats->num_record_drop_obsolete++;
continue;
}
auto kv = tombstone.Serialize();
sub_compact->builder->Add(kv.first.Encode(), kv.second);
InternalKey smallest_candidate = std::move(kv.first);
if (lower_bound != nullptr &&
ucmp->Compare(smallest_candidate.user_key(), *lower_bound) <= 0) {
// Pretend the smallest key has the same user key as lower_bound
// (the max key in the previous table or subcompaction) in order for
// files to appear key-space partitioned.
//
// When lower_bound is chosen by a subcompaction, we know that
// subcompactions over smaller keys cannot contain any keys at
// lower_bound. We also know that smaller subcompactions exist, because
// otherwise the subcompaction woud be unbounded on the left. As a
// result, we know that no other files on the output level will contain
// actual keys at lower_bound (an output file may have a largest key of
// lower_bound@kMaxSequenceNumber, but this only indicates a large range
// tombstone was truncated). Therefore, it is safe to use the
// tombstone's sequence number, to ensure that keys at lower_bound at
// lower levels are covered by truncated tombstones.
//
// If lower_bound was chosen by the smallest data key in the file,
// choose lowest seqnum so this file's smallest internal key comes after
// the previous file's largest. The fake seqnum is OK because the read
// path's file-picking code only considers user key.
smallest_candidate = InternalKey(
*lower_bound, lower_bound_from_sub_compact ? tombstone.seq_ : 0,
kTypeRangeDeletion);
}
InternalKey largest_candidate = tombstone.SerializeEndKey();
if (upper_bound != nullptr &&
ucmp->Compare(*upper_bound, largest_candidate.user_key()) <= 0) {
// Pretend the largest key has the same user key as upper_bound (the
// min key in the following table or subcompaction) in order for files
// to appear key-space partitioned.
//
// Choose highest seqnum so this file's largest internal key comes
// before the next file's/subcompaction's smallest. The fake seqnum is
// OK because the read path's file-picking code only considers the user
// key portion.
//
// Note Seek() also creates InternalKey with (user_key,
// kMaxSequenceNumber), but with kTypeDeletion (0x7) instead of
// kTypeRangeDeletion (0xF), so the range tombstone comes before the
// Seek() key in InternalKey's ordering. So Seek() will look in the
// next file for the user key.
largest_candidate =
InternalKey(*upper_bound, kMaxSequenceNumber, kTypeRangeDeletion);
}
#ifndef NDEBUG
SequenceNumber smallest_ikey_seqnum = kMaxSequenceNumber;
if (meta->smallest.size() > 0) {
smallest_ikey_seqnum = GetInternalKeySeqno(meta->smallest.Encode());
}
#endif
meta->UpdateBoundariesForRange(smallest_candidate, largest_candidate,
tombstone.seq_,
cfd->internal_comparator());
// The smallest key in a file is used for range tombstone truncation, so
// it cannot have a seqnum of 0 (unless the smallest data key in a file
// has a seqnum of 0). Otherwise, the truncated tombstone may expose
// deleted keys at lower levels.
assert(smallest_ikey_seqnum == 0 ||
ExtractInternalKeyFooter(meta->smallest.Encode()) !=
PackSequenceAndType(0, kTypeRangeDeletion));
}
meta->marked_for_compaction = sub_compact->builder->NeedCompact();
}
const uint64_t current_entries = sub_compact->builder->NumEntries();
if (s.ok()) {
s = sub_compact->builder->Finish();
} else {
sub_compact->builder->Abandon();
}
const uint64_t current_bytes = sub_compact->builder->FileSize();
if (s.ok()) {
meta->fd.file_size = current_bytes;
}
sub_compact->current_output()->finished = true;
sub_compact->total_bytes += current_bytes;
// Finish and check for file errors
if (s.ok()) {
StopWatch sw(env_, stats_, COMPACTION_OUTFILE_SYNC_MICROS);
s = sub_compact->outfile->Sync(db_options_.use_fsync);
}
if (s.ok()) {
s = sub_compact->outfile->Close();
}
sub_compact->outfile.reset();
TableProperties tp;
if (s.ok()) {
tp = sub_compact->builder->GetTableProperties();
}
if (s.ok() && current_entries == 0 && tp.num_range_deletions == 0) {
// If there is nothing to output, no necessary to generate a sst file.
// This happens when the output level is bottom level, at the same time
// the sub_compact output nothing.
std::string fname =
TableFileName(sub_compact->compaction->immutable_cf_options()->cf_paths,
meta->fd.GetNumber(), meta->fd.GetPathId());
env_->DeleteFile(fname);
// Also need to remove the file from outputs, or it will be added to the
// VersionEdit.
assert(!sub_compact->outputs.empty());
sub_compact->outputs.pop_back();
meta = nullptr;
}
if (s.ok() && (current_entries > 0 || tp.num_range_deletions > 0)) {
// Output to event logger and fire events.
sub_compact->current_output()->table_properties =
std::make_shared<TableProperties>(tp);
ROCKS_LOG_INFO(db_options_.info_log,
"[%s] [JOB %d] Generated table #%" PRIu64 ": %" PRIu64
" keys, %" PRIu64 " bytes%s",
cfd->GetName().c_str(), job_id_, output_number,
current_entries, current_bytes,
meta->marked_for_compaction ? " (need compaction)" : "");
}
std::string fname;
FileDescriptor output_fd;
if (meta != nullptr) {
fname =
TableFileName(sub_compact->compaction->immutable_cf_options()->cf_paths,
meta->fd.GetNumber(), meta->fd.GetPathId());
output_fd = meta->fd;
} else {
fname = "(nil)";
}
EventHelpers::LogAndNotifyTableFileCreationFinished(
event_logger_, cfd->ioptions()->listeners, dbname_, cfd->GetName(), fname,
job_id_, output_fd, tp, TableFileCreationReason::kCompaction, s);
#ifndef ROCKSDB_LITE
// Report new file to SstFileManagerImpl
auto sfm =
static_cast<SstFileManagerImpl*>(db_options_.sst_file_manager.get());
if (sfm && meta != nullptr && meta->fd.GetPathId() == 0) {
auto fn =
TableFileName(sub_compact->compaction->immutable_cf_options()->cf_paths,
meta->fd.GetNumber(), meta->fd.GetPathId());
sfm->OnAddFile(fn);
if (sfm->IsMaxAllowedSpaceReached()) {
// TODO(ajkr): should we return OK() if max space was reached by the final
// compaction output file (similarly to how flush works when full)?
s = Status::SpaceLimit("Max allowed space was reached");
TEST_SYNC_POINT(
"CompactionJob::FinishCompactionOutputFile:"
"MaxAllowedSpaceReached");
InstrumentedMutexLock l(db_mutex_);
db_error_handler_->SetBGError(s, BackgroundErrorReason::kCompaction);
}
}
#endif
sub_compact->builder.reset();
sub_compact->current_output_file_size = 0;
return s;
}
Status CompactionJob::InstallCompactionResults(
const MutableCFOptions& mutable_cf_options) {
db_mutex_->AssertHeld();
auto* compaction = compact_->compaction;
// paranoia: verify that the files that we started with
// still exist in the current version and in the same original level.
// This ensures that a concurrent compaction did not erroneously
// pick the same files to compact_.
if (!versions_->VerifyCompactionFileConsistency(compaction)) {
Compaction::InputLevelSummaryBuffer inputs_summary;
ROCKS_LOG_ERROR(db_options_.info_log, "[%s] [JOB %d] Compaction %s aborted",
compaction->column_family_data()->GetName().c_str(),
job_id_, compaction->InputLevelSummary(&inputs_summary));
return Status::Corruption("Compaction input files inconsistent");
}
{
Compaction::InputLevelSummaryBuffer inputs_summary;
ROCKS_LOG_INFO(
db_options_.info_log, "[%s] [JOB %d] Compacted %s => %" PRIu64 " bytes",
compaction->column_family_data()->GetName().c_str(), job_id_,
compaction->InputLevelSummary(&inputs_summary), compact_->total_bytes);
}
// Add compaction inputs
compaction->AddInputDeletions(compact_->compaction->edit());
for (const auto& sub_compact : compact_->sub_compact_states) {
for (const auto& out : sub_compact.outputs) {
compaction->edit()->AddFile(compaction->output_level(), out.meta);
}
}
return versions_->LogAndApply(compaction->column_family_data(),
mutable_cf_options, compaction->edit(),
db_mutex_, db_directory_);
}
void CompactionJob::RecordCompactionIOStats() {
RecordTick(stats_, COMPACT_READ_BYTES, IOSTATS(bytes_read));
ThreadStatusUtil::IncreaseThreadOperationProperty(
ThreadStatus::COMPACTION_BYTES_READ, IOSTATS(bytes_read));
IOSTATS_RESET(bytes_read);
RecordTick(stats_, COMPACT_WRITE_BYTES, IOSTATS(bytes_written));
ThreadStatusUtil::IncreaseThreadOperationProperty(
ThreadStatus::COMPACTION_BYTES_WRITTEN, IOSTATS(bytes_written));
IOSTATS_RESET(bytes_written);
}
Status CompactionJob::OpenCompactionOutputFile(
SubcompactionState* sub_compact) {
assert(sub_compact != nullptr);
assert(sub_compact->builder == nullptr);
// no need to lock because VersionSet::next_file_number_ is atomic
uint64_t file_number = versions_->NewFileNumber();
std::string fname =
TableFileName(sub_compact->compaction->immutable_cf_options()->cf_paths,
file_number, sub_compact->compaction->output_path_id());
// Fire events.
ColumnFamilyData* cfd = sub_compact->compaction->column_family_data();
#ifndef ROCKSDB_LITE
EventHelpers::NotifyTableFileCreationStarted(
cfd->ioptions()->listeners, dbname_, cfd->GetName(), fname, job_id_,
TableFileCreationReason::kCompaction);
#endif // !ROCKSDB_LITE
// Make the output file
std::unique_ptr<WritableFile> writable_file;
#ifndef NDEBUG
bool syncpoint_arg = env_options_.use_direct_writes;
TEST_SYNC_POINT_CALLBACK("CompactionJob::OpenCompactionOutputFile",
&syncpoint_arg);
#endif
Status s = NewWritableFile(env_, fname, &writable_file, env_options_);
if (!s.ok()) {
ROCKS_LOG_ERROR(
db_options_.info_log,
"[%s] [JOB %d] OpenCompactionOutputFiles for table #%" PRIu64
" fails at NewWritableFile with status %s",
sub_compact->compaction->column_family_data()->GetName().c_str(),
job_id_, file_number, s.ToString().c_str());
LogFlush(db_options_.info_log);
EventHelpers::LogAndNotifyTableFileCreationFinished(
event_logger_, cfd->ioptions()->listeners, dbname_, cfd->GetName(),
fname, job_id_, FileDescriptor(), TableProperties(),
TableFileCreationReason::kCompaction, s);
return s;
}
SubcompactionState::Output out;
out.meta.fd =
FileDescriptor(file_number, sub_compact->compaction->output_path_id(), 0);
out.finished = false;
sub_compact->outputs.push_back(out);
writable_file->SetIOPriority(Env::IO_LOW);
writable_file->SetWriteLifeTimeHint(write_hint_);
writable_file->SetPreallocationBlockSize(static_cast<size_t>(
sub_compact->compaction->OutputFilePreallocationSize()));
const auto& listeners =
sub_compact->compaction->immutable_cf_options()->listeners;
sub_compact->outfile.reset(
new WritableFileWriter(std::move(writable_file), fname, env_options_,
db_options_.statistics.get(), listeners));
// If the Column family flag is to only optimize filters for hits,
// we can skip creating filters if this is the bottommost_level where
// data is going to be found
bool skip_filters =
cfd->ioptions()->optimize_filters_for_hits && bottommost_level_;
uint64_t output_file_creation_time =
sub_compact->compaction->MaxInputFileCreationTime();
if (output_file_creation_time == 0) {
int64_t _current_time = 0;
auto status = db_options_.env->GetCurrentTime(&_current_time);
// Safe to proceed even if GetCurrentTime fails. So, log and proceed.
if (!status.ok()) {
ROCKS_LOG_WARN(
db_options_.info_log,
"Failed to get current time to populate creation_time property. "
"Status: %s",
status.ToString().c_str());
}
output_file_creation_time = static_cast<uint64_t>(_current_time);
}
sub_compact->builder.reset(NewTableBuilder(
*cfd->ioptions(), *(sub_compact->compaction->mutable_cf_options()),
cfd->internal_comparator(), cfd->int_tbl_prop_collector_factories(),
cfd->GetID(), cfd->GetName(), sub_compact->outfile.get(),
sub_compact->compaction->output_compression(),
sub_compact->compaction->output_compression_opts(),
sub_compact->compaction->output_level(), &sub_compact->compression_dict,
skip_filters, output_file_creation_time));
LogFlush(db_options_.info_log);
return s;
}
void CompactionJob::CleanupCompaction() {
for (SubcompactionState& sub_compact : compact_->sub_compact_states) {
const auto& sub_status = sub_compact.status;
if (sub_compact.builder != nullptr) {
// May happen if we get a shutdown call in the middle of compaction
sub_compact.builder->Abandon();
sub_compact.builder.reset();
} else {
assert(!sub_status.ok() || sub_compact.outfile == nullptr);
}
for (const auto& out : sub_compact.outputs) {
// If this file was inserted into the table cache then remove
// them here because this compaction was not committed.
if (!sub_status.ok()) {
TableCache::Evict(table_cache_.get(), out.meta.fd.GetNumber());
}
}
}
delete compact_;
compact_ = nullptr;
}
#ifndef ROCKSDB_LITE
namespace {
void CopyPrefix(const Slice& src, size_t prefix_length, std::string* dst) {
assert(prefix_length > 0);
size_t length = src.size() > prefix_length ? prefix_length : src.size();
dst->assign(src.data(), length);
}
} // namespace
#endif // !ROCKSDB_LITE
void CompactionJob::UpdateCompactionStats() {
Compaction* compaction = compact_->compaction;
compaction_stats_.num_input_files_in_non_output_levels = 0;
compaction_stats_.num_input_files_in_output_level = 0;
for (int input_level = 0;
input_level < static_cast<int>(compaction->num_input_levels());
++input_level) {
if (compaction->level(input_level) != compaction->output_level()) {
UpdateCompactionInputStatsHelper(
&compaction_stats_.num_input_files_in_non_output_levels,
&compaction_stats_.bytes_read_non_output_levels, input_level);
} else {
UpdateCompactionInputStatsHelper(
&compaction_stats_.num_input_files_in_output_level,
&compaction_stats_.bytes_read_output_level, input_level);
}
}
for (const auto& sub_compact : compact_->sub_compact_states) {
size_t num_output_files = sub_compact.outputs.size();
if (sub_compact.builder != nullptr) {
// An error occurred so ignore the last output.
assert(num_output_files > 0);
--num_output_files;
}
compaction_stats_.num_output_files += static_cast<int>(num_output_files);
for (const auto& out : sub_compact.outputs) {
compaction_stats_.bytes_written += out.meta.fd.file_size;
}
if (sub_compact.num_input_records > sub_compact.num_output_records) {
compaction_stats_.num_dropped_records +=
sub_compact.num_input_records - sub_compact.num_output_records;
}
}
}
void CompactionJob::UpdateCompactionInputStatsHelper(int* num_files,
uint64_t* bytes_read,
int input_level) {
const Compaction* compaction = compact_->compaction;
auto num_input_files = compaction->num_input_files(input_level);
*num_files += static_cast<int>(num_input_files);
for (size_t i = 0; i < num_input_files; ++i) {
const auto* file_meta = compaction->input(input_level, i);
*bytes_read += file_meta->fd.GetFileSize();
compaction_stats_.num_input_records +=
static_cast<uint64_t>(file_meta->num_entries);
}
}
void CompactionJob::UpdateCompactionJobStats(
const InternalStats::CompactionStats& stats) const {
#ifndef ROCKSDB_LITE
if (compaction_job_stats_) {
compaction_job_stats_->elapsed_micros = stats.micros;
// input information
compaction_job_stats_->total_input_bytes =
stats.bytes_read_non_output_levels + stats.bytes_read_output_level;
compaction_job_stats_->num_input_records = compact_->num_input_records;
compaction_job_stats_->num_input_files =
stats.num_input_files_in_non_output_levels +
stats.num_input_files_in_output_level;
compaction_job_stats_->num_input_files_at_output_level =
stats.num_input_files_in_output_level;
// output information
compaction_job_stats_->total_output_bytes = stats.bytes_written;
compaction_job_stats_->num_output_records = compact_->num_output_records;
compaction_job_stats_->num_output_files = stats.num_output_files;
if (compact_->NumOutputFiles() > 0U) {
CopyPrefix(compact_->SmallestUserKey(),
CompactionJobStats::kMaxPrefixLength,
&compaction_job_stats_->smallest_output_key_prefix);
CopyPrefix(compact_->LargestUserKey(),
CompactionJobStats::kMaxPrefixLength,
&compaction_job_stats_->largest_output_key_prefix);
}
}
#else
(void)stats;
#endif // !ROCKSDB_LITE
}
void CompactionJob::LogCompaction() {
Compaction* compaction = compact_->compaction;
ColumnFamilyData* cfd = compaction->column_family_data();
// Let's check if anything will get logged. Don't prepare all the info if
// we're not logging
if (db_options_.info_log_level <= InfoLogLevel::INFO_LEVEL) {
Compaction::InputLevelSummaryBuffer inputs_summary;
ROCKS_LOG_INFO(
db_options_.info_log, "[%s] [JOB %d] Compacting %s, score %.2f",
cfd->GetName().c_str(), job_id_,
compaction->InputLevelSummary(&inputs_summary), compaction->score());
char scratch[2345];
compaction->Summary(scratch, sizeof(scratch));
ROCKS_LOG_INFO(db_options_.info_log, "[%s] Compaction start summary: %s\n",
cfd->GetName().c_str(), scratch);
// build event logger report
auto stream = event_logger_->Log();
stream << "job" << job_id_ << "event"
<< "compaction_started"
<< "compaction_reason"
<< GetCompactionReasonString(compaction->compaction_reason());
for (size_t i = 0; i < compaction->num_input_levels(); ++i) {
stream << ("files_L" + ToString(compaction->level(i)));
stream.StartArray();
for (auto f : *compaction->inputs(i)) {
stream << f->fd.GetNumber();
}
stream.EndArray();
}
stream << "score" << compaction->score() << "input_data_size"
<< compaction->CalculateTotalInputSize();
}
}
} // namespace rocksdb