rocksdb/db/db_impl_experimental.cc
Giuseppe Ottaviano 2dc421df48 Implement DB::PromoteL0 method
Summary:
This diff implements a new `DB` method `PromoteL0` which moves all files in L0
to a given level skipping compaction, provided that the files have disjoint
ranges and all levels up to the target level are empty.

This method provides finer-grain control for trivial compactions, and it is
useful for bulk-loading pre-sorted keys. Compared to D34797, it does not change
the semantics of an existing operation, which can impact existing code.

PromoteL0 is designed to work well in combination with the proposed
`GetSstFileWriter`/`AddFile` interface, enabling to "design" the level structure
by populating one level at a time. Such fine-grained control can be very useful
for static or mostly-static databases.

Test Plan: `make check`

Reviewers: IslamAbdelRahman, philipp, MarkCallaghan, yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D37107
2015-04-23 12:10:36 -07:00

151 lines
5.3 KiB
C++

// Copyright (c) 2013, 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.
//
// 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/db_impl.h"
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#include <vector>
#include "db/column_family.h"
#include "db/job_context.h"
#include "db/version_set.h"
#include "rocksdb/status.h"
namespace rocksdb {
#ifndef ROCKSDB_LITE
Status DBImpl::SuggestCompactRange(ColumnFamilyHandle* column_family,
const Slice* begin, const Slice* end) {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
auto cfd = cfh->cfd();
InternalKey start_key, end_key;
if (begin != nullptr) {
start_key = InternalKey(*begin, kMaxSequenceNumber, kValueTypeForSeek);
}
if (end != nullptr) {
end_key = InternalKey(*end, 0, static_cast<ValueType>(0));
}
{
InstrumentedMutexLock l(&mutex_);
auto vstorage = cfd->current()->storage_info();
for (int level = 0; level < vstorage->num_non_empty_levels(); ++level) {
std::vector<FileMetaData*> inputs;
vstorage->GetOverlappingInputs(
level, begin == nullptr ? nullptr : &start_key,
end == nullptr ? nullptr : &end_key, &inputs);
for (auto f : inputs) {
f->marked_for_compaction = true;
}
}
// Since we have some more files to compact, we should also recompute
// compaction score
vstorage->ComputeCompactionScore(*cfd->GetLatestMutableCFOptions(),
CompactionOptionsFIFO());
SchedulePendingCompaction(cfd);
MaybeScheduleFlushOrCompaction();
}
return Status::OK();
}
Status DBImpl::PromoteL0(ColumnFamilyHandle* column_family, int target_level) {
assert(column_family);
if (target_level < 1) {
Log(InfoLogLevel::INFO_LEVEL, db_options_.info_log,
"PromoteL0 FAILED. Invalid target level %d\n", target_level);
return Status::InvalidArgument("Invalid target level");
}
Status status;
VersionEdit edit;
JobContext job_context(next_job_id_.fetch_add(1), true);
{
InstrumentedMutexLock l(&mutex_);
auto* cfd = static_cast<ColumnFamilyHandleImpl*>(column_family)->cfd();
const auto* vstorage = cfd->current()->storage_info();
if (target_level >= vstorage->num_levels()) {
Log(InfoLogLevel::INFO_LEVEL, db_options_.info_log,
"PromoteL0 FAILED. Target level %d does not exist\n", target_level);
job_context.Clean();
return Status::InvalidArgument("Target level does not exist");
}
// Sort L0 files by range.
const InternalKeyComparator* icmp = &cfd->internal_comparator();
auto l0_files = vstorage->LevelFiles(0);
std::sort(l0_files.begin(), l0_files.end(),
[icmp](FileMetaData* f1, FileMetaData* f2) {
return icmp->Compare(f1->largest, f2->largest) < 0;
});
// Check that no L0 file is being compacted and that they have
// non-overlapping ranges.
for (size_t i = 0; i < l0_files.size(); ++i) {
auto f = l0_files[i];
if (f->being_compacted) {
Log(InfoLogLevel::INFO_LEVEL, db_options_.info_log,
"PromoteL0 FAILED. File %" PRIu64 " being compacted\n",
f->fd.GetNumber());
job_context.Clean();
return Status::InvalidArgument("PromoteL0 called during L0 compaction");
}
if (i == 0) continue;
auto prev_f = l0_files[i - 1];
if (icmp->Compare(prev_f->largest, f->smallest) >= 0) {
Log(InfoLogLevel::INFO_LEVEL, db_options_.info_log,
"PromoteL0 FAILED. Files %" PRIu64 " and %" PRIu64
" have overlapping ranges\n",
prev_f->fd.GetNumber(), f->fd.GetNumber());
job_context.Clean();
return Status::InvalidArgument("L0 has overlapping files");
}
}
// Check that all levels up to target_level are empty.
for (int level = 1; level <= target_level; ++level) {
if (vstorage->NumLevelFiles(level) > 0) {
Log(InfoLogLevel::INFO_LEVEL, db_options_.info_log,
"PromoteL0 FAILED. Level %d not empty\n", level);
job_context.Clean();
return Status::InvalidArgument(
"All levels up to target_level "
"must be empty");
}
}
edit.SetColumnFamily(cfd->GetID());
for (const auto& f : l0_files) {
edit.DeleteFile(0, f->fd.GetNumber());
edit.AddFile(target_level, f->fd.GetNumber(), f->fd.GetPathId(),
f->fd.GetFileSize(), f->smallest, f->largest,
f->smallest_seqno, f->largest_seqno);
}
status = versions_->LogAndApply(cfd, *cfd->GetLatestMutableCFOptions(),
&edit, &mutex_, directories_.GetDbDir());
if (status.ok()) {
InstallSuperVersionBackground(cfd, &job_context,
*cfd->GetLatestMutableCFOptions());
}
} // lock released here
LogFlush(db_options_.info_log);
job_context.Clean();
return status;
}
#endif // ROCKSDB_LITE
} // namespace rocksdb