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Blob DB: remove existing garbage collection implementation

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Summary:
Red diff to remove existing implementation of garbage collection. The current approach is reference counting kind of approach and require a lot of effort to get the size counter right on compaction and deletion. I'm going to go with a simple mark-sweep kind of approach and will send another PR for that.

CompactionEventListener was added solely for blob db and it adds complexity and overhead to compaction iterator. Removing it as well.
Closes https://github.com/facebook/rocksdb/pull/3551

Differential Revision: D7130190

Pulled By: yiwu-arbug

fbshipit-source-id: c3a375ad2639a3f6ed179df6eda602372cc5b8df
This commit is contained in:
Yi Wu 2018-03-02 12:54:24 -08:00 committed by Facebook Github Bot
parent 2ac988c67e
commit 1209b6db5c
12 changed files with 25 additions and 787 deletions
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1
HISTORY.md
View File

@ -2,6 +2,7 @@
## Unreleased
### Public API Change
* RocksDBOptionsParser::Parse()'s `ignore_unknown_options` argument will only be effective if the option file shows it is generated using a higher version of RocksDB than the current version.
* Remove CompactionEventListener.
### New Features
* Avoid unnecessarily flushing in `CompactRange()` when the range specified by the user does not overlap unflushed memtables.

49
db/compaction_iterator.cc
View File

@ -12,31 +12,6 @@
namespace rocksdb {
#ifndef ROCKSDB_LITE
CompactionEventListener::CompactionListenerValueType fromInternalValueType(
ValueType vt) {
switch (vt) {
case kTypeDeletion:
return CompactionEventListener::CompactionListenerValueType::kDelete;
case kTypeValue:
return CompactionEventListener::CompactionListenerValueType::kValue;
case kTypeMerge:
return CompactionEventListener::CompactionListenerValueType::
kMergeOperand;
case kTypeSingleDeletion:
return CompactionEventListener::CompactionListenerValueType::
kSingleDelete;
case kTypeRangeDeletion:
return CompactionEventListener::CompactionListenerValueType::kRangeDelete;
case kTypeBlobIndex:
return CompactionEventListener::CompactionListenerValueType::kBlobIndex;
default:
assert(false);
return CompactionEventListener::CompactionListenerValueType::kInvalid;
}
}
#endif // ROCKSDB_LITE
CompactionIterator::CompactionIterator(
InternalIterator* input, const Comparator* cmp, MergeHelper* merge_helper,
SequenceNumber last_sequence, std::vector<SequenceNumber>* snapshots,
@ -44,7 +19,6 @@ CompactionIterator::CompactionIterator(
const SnapshotChecker* snapshot_checker, Env* env,
bool expect_valid_internal_key, RangeDelAggregator* range_del_agg,
const Compaction* compaction, const CompactionFilter* compaction_filter,
CompactionEventListener* compaction_listener,
const std::atomic<bool>* shutting_down,
const SequenceNumber preserve_deletes_seqnum)
: CompactionIterator(
@ -53,8 +27,7 @@ CompactionIterator::CompactionIterator(
expect_valid_internal_key, range_del_agg,
std::unique_ptr<CompactionProxy>(
compaction ? new CompactionProxy(compaction) : nullptr),
compaction_filter, compaction_listener, shutting_down,
preserve_deletes_seqnum) {}
compaction_filter, shutting_down, preserve_deletes_seqnum) {}
CompactionIterator::CompactionIterator(
InternalIterator* input, const Comparator* cmp, MergeHelper* merge_helper,
@ -64,7 +37,6 @@ CompactionIterator::CompactionIterator(
bool expect_valid_internal_key, RangeDelAggregator* range_del_agg,
std::unique_ptr<CompactionProxy> compaction,
const CompactionFilter* compaction_filter,
CompactionEventListener* compaction_listener,
const std::atomic<bool>* shutting_down,
const SequenceNumber preserve_deletes_seqnum
)
@ -79,9 +51,6 @@ CompactionIterator::CompactionIterator(
range_del_agg_(range_del_agg),
compaction_(std::move(compaction)),
compaction_filter_(compaction_filter),
#ifndef ROCKSDB_LITE
compaction_listener_(compaction_listener),
#endif // ROCKSDB_LITE
shutting_down_(shutting_down),
preserve_deletes_seqnum_(preserve_deletes_seqnum),
ignore_snapshots_(false),
@ -293,28 +262,12 @@ void CompactionIterator::NextFromInput() {
(snapshot_checker_ == nullptr ||
snapshot_checker_->IsInSnapshot(ikey_.sequence, kMaxSequenceNumber));
#ifndef ROCKSDB_LITE
if (compaction_listener_) {
compaction_listener_->OnCompaction(compaction_->level(), ikey_.user_key,
fromInternalValueType(ikey_.type),
value_, ikey_.sequence, true);
}
#endif // !ROCKSDB_LITE
// Apply the compaction filter to the first committed version of the user
// key.
if (current_key_committed_) {
InvokeFilterIfNeeded(&need_skip, &skip_until);
}
} else {
#ifndef ROCKSDB_LITE
if (compaction_listener_) {
compaction_listener_->OnCompaction(compaction_->level(), ikey_.user_key,
fromInternalValueType(ikey_.type),
value_, ikey_.sequence, false);
}
#endif // ROCKSDB_LITE
// Update the current key to reflect the new sequence number/type without
// copying the user key.
// TODO(rven): Compaction filter does not process keys in this path

7
db/compaction_iterator.h
View File

@ -20,8 +20,6 @@
namespace rocksdb {
class CompactionEventListener;
class CompactionIterator {
public:
// A wrapper around Compaction. Has a much smaller interface, only what
@ -69,7 +67,6 @@ class CompactionIterator {
RangeDelAggregator* range_del_agg,
const Compaction* compaction = nullptr,
const CompactionFilter* compaction_filter = nullptr,
CompactionEventListener* compaction_listener = nullptr,
const std::atomic<bool>* shutting_down = nullptr,
const SequenceNumber preserve_deletes_seqnum = 0);
@ -83,7 +80,6 @@ class CompactionIterator {
RangeDelAggregator* range_del_agg,
std::unique_ptr<CompactionProxy> compaction,
const CompactionFilter* compaction_filter = nullptr,
CompactionEventListener* compaction_listener = nullptr,
const std::atomic<bool>* shutting_down = nullptr,
const SequenceNumber preserve_deletes_seqnum = 0);
@ -147,9 +143,6 @@ class CompactionIterator {
RangeDelAggregator* range_del_agg_;
std::unique_ptr<CompactionProxy> compaction_;
const CompactionFilter* compaction_filter_;
#ifndef ROCKSDB_LITE
CompactionEventListener* compaction_listener_;
#endif // !ROCKSDB_LITE
const std::atomic<bool>* shutting_down_;
const SequenceNumber preserve_deletes_seqnum_;
bool bottommost_level_;

2
db/compaction_iterator_test.cc
View File

@ -245,7 +245,7 @@ class CompactionIteratorTest : public testing::TestWithParam<bool> {
iter_.get(), cmp_, merge_helper_.get(), last_sequence, &snapshots_,
earliest_write_conflict_snapshot, snapshot_checker_.get(),
Env::Default(), false, range_del_agg_.get(), std::move(compaction),
filter, nullptr, &shutting_down_));
filter, &shutting_down_));
}
void AddSnapshot(SequenceNumber snapshot,

15
db/compaction_job.cc
View File

@ -762,24 +762,13 @@ void CompactionJob::ProcessKeyValueCompaction(SubcompactionState* sub_compact) {
input->SeekToFirst();
}
// we allow only 1 compaction event listener. Used by blob storage
CompactionEventListener* comp_event_listener = nullptr;
#ifndef ROCKSDB_LITE
for (auto& celitr : cfd->ioptions()->listeners) {
comp_event_listener = celitr->GetCompactionEventListener();
if (comp_event_listener != nullptr) {
break;
}
}
#endif // ROCKSDB_LITE
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_, false, range_del_agg.get(),
sub_compact->compaction, compaction_filter, comp_event_listener,
shutting_down_, preserve_deletes_seqnum_));
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() &&

30
include/rocksdb/listener.h
View File

@ -227,30 +227,6 @@ struct ExternalFileIngestionInfo {
TableProperties table_properties;
};
// A call-back function to RocksDB which will be called when the compaction
// iterator is compacting values. It is meant to be returned from
// EventListner::GetCompactionEventListner() at the beginning of compaction
// job.
class CompactionEventListener {
public:
enum CompactionListenerValueType {
kValue,
kMergeOperand,
kDelete,
kSingleDelete,
kRangeDelete,
kBlobIndex,
kInvalid,
};
virtual void OnCompaction(int level, const Slice& key,
CompactionListenerValueType value_type,
const Slice& existing_value,
const SequenceNumber& sn, bool is_new) = 0;
virtual ~CompactionEventListener() = default;
};
// EventListener class contains a set of call-back functions that will
// be called when specific RocksDB event happens such as flush. It can
// be used as a building block for developing custom features such as
@ -413,12 +389,6 @@ class EventListener {
// returns. Otherwise, RocksDB may be blocked.
virtual void OnStallConditionsChanged(const WriteStallInfo& /*info*/) {}
// Factory method to return CompactionEventListener. If multiple listeners
// provides CompactionEventListner, only the first one will be used.
virtual CompactionEventListener* GetCompactionEventListener() {
return nullptr;
}
virtual ~EventListener() {}
};

158
util/mpsc.h
View File

@ -1,158 +0,0 @@
// Portions 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).
//
// Large parts of this file is borrowed from the public domain code below.
// from https://github.com/mstump/queues
// C++ implementation of Dmitry Vyukov's non-intrusive
// lock free unbound MPSC queue
// http://www.1024cores.net/home/
// lock-free-algorithms/queues/non-intrusive-mpsc-node-based-queue
// License from mstump/queues
// This is free and unencumbered software released into the public domain.
//
// Anyone is free to copy, modify, publish, use, compile, sell, or
// distribute this software, either in source code form or as a compiled
// binary, for any purpose, commercial or non-commercial, and by any
// means.
//
// In jurisdictions that recognize copyright laws, the author or authors
// of this software dedicate any and all copyright interest in the
// software to the public domain. We make this dedication for the benefit
// of the public at large and to the detriment of our heirs and
// successors. We intend this dedication to be an overt act of
// relinquishment in perpetuity of all present and future rights to this
// software under copyright law.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
// IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
// OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
//
// For more information, please refer to <http://unlicense.org>
// License from http://www.1024cores.net/home/
// lock-free-algorithms/queues/non-intrusive-mpsc-node-based-queue
// Copyright (c) 2010-2011 Dmitry Vyukov. All rights reserved.
// Redistribution and use in source and binary forms, with or
// without modification, are permitted provided that the following
// conditions are met:
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY DMITRY VYUKOV "AS IS" AND ANY EXPRESS OR
// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
// OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
// EVENT SHALL DMITRY VYUKOV OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
// USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// The views and conclusions contained in the software and documentation
// are those of the authors and should not be interpreted as representing
// official policies, either expressed or implied, of Dmitry Vyukov.
//
#ifndef UTIL_MPSC_H_
#define UTIL_MPSC_H_
#include <atomic>
#include <cassert>
#include <type_traits>
/**
* Multiple Producer Single Consumer Lockless Q
*/
template <typename T>
class mpsc_queue_t {
public:
struct buffer_node_t {
T data;
std::atomic<buffer_node_t*> next;
};
mpsc_queue_t() {
buffer_node_aligned_t* al_st = new buffer_node_aligned_t;
buffer_node_t* node = new (al_st) buffer_node_t();
_head.store(node);
_tail.store(node);
node->next.store(nullptr, std::memory_order_relaxed);
}
~mpsc_queue_t() {
T output;
while (this->dequeue(&output)) {
}
buffer_node_t* front = _head.load(std::memory_order_relaxed);
front->~buffer_node_t();
::operator delete(front);
}
void enqueue(const T& input) {
buffer_node_aligned_t* al_st = new buffer_node_aligned_t;
buffer_node_t* node = new (al_st) buffer_node_t();
node->data = input;
node->next.store(nullptr, std::memory_order_relaxed);
buffer_node_t* prev_head = _head.exchange(node, std::memory_order_acq_rel);
prev_head->next.store(node, std::memory_order_release);
}
bool dequeue(T* output) {
buffer_node_t* tail = _tail.load(std::memory_order_relaxed);
buffer_node_t* next = tail->next.load(std::memory_order_acquire);
if (next == nullptr) {
return false;
}
*output = next->data;
_tail.store(next, std::memory_order_release);
tail->~buffer_node_t();
::operator delete(tail);
return true;
}
// you can only use pop_all if the queue is SPSC
buffer_node_t* pop_all() {
// nobody else can move the tail pointer.
buffer_node_t* tptr = _tail.load(std::memory_order_relaxed);
buffer_node_t* next =
tptr->next.exchange(nullptr, std::memory_order_acquire);
_head.exchange(tptr, std::memory_order_acquire);
// there is a race condition here
return next;
}
private:
typedef typename std::aligned_storage<
sizeof(buffer_node_t), std::alignment_of<buffer_node_t>::value>::type
buffer_node_aligned_t;
std::atomic<buffer_node_t*> _head;
std::atomic<buffer_node_t*> _tail;
mpsc_queue_t(const mpsc_queue_t&) = delete;
mpsc_queue_t& operator=(const mpsc_queue_t&) = delete;
};
#endif // UTIL_MPSC_H_

5
utilities/blob_db/blob_db.h
View File

@ -107,8 +107,6 @@ class BlobDB : public StackableDB {
}
using rocksdb::StackableDB::Delete;
virtual Status Delete(const WriteOptions& options,
const Slice& key) override = 0;
virtual Status Delete(const WriteOptions& options,
ColumnFamilyHandle* column_family,
const Slice& key) override {
@ -116,7 +114,8 @@ class BlobDB : public StackableDB {
return Status::NotSupported(
"Blob DB doesn't support non-default column family.");
}
return Delete(options, key);
assert(db_ != nullptr);
return db_->Delete(options, column_family, key);
}
virtual Status PutWithTTL(const WriteOptions& options, const Slice& key,

422
utilities/blob_db/blob_db_impl.cc
View File

@ -66,37 +66,6 @@ bool blobf_compare_ttl::operator()(const std::shared_ptr<BlobFile>& lhs,
return lhs->BlobFileNumber() < rhs->BlobFileNumber();
}
void EvictAllVersionsCompactionListener::InternalListener::OnCompaction(
int level, const Slice& key,
CompactionEventListener::CompactionListenerValueType value_type,
const Slice& existing_value, const SequenceNumber& sn, bool is_new) {
assert(impl_->bdb_options_.enable_garbage_collection);
if (!is_new &&
value_type ==
CompactionEventListener::CompactionListenerValueType::kValue) {
BlobIndex blob_index;
Status s = blob_index.DecodeFrom(existing_value);
if (s.ok()) {
if (impl_->debug_level_ >= 3)
ROCKS_LOG_INFO(
impl_->db_options_.info_log,
"CALLBACK COMPACTED OUT KEY: %s SN: %d "
"NEW: %d FN: %" PRIu64 " OFFSET: %" PRIu64 " SIZE: %" PRIu64,
key.ToString().c_str(), sn, is_new, blob_index.file_number(),
blob_index.offset(), blob_index.size());
impl_->override_vals_q_.enqueue({blob_index.file_number(), key.size(),
blob_index.offset(), blob_index.size(),
sn});
}
} else {
if (impl_->debug_level_ >= 3)
ROCKS_LOG_INFO(impl_->db_options_.info_log,
"CALLBACK NEW KEY: %s SN: %d NEW: %d",
key.ToString().c_str(), sn, is_new);
}
}
BlobDBImpl::BlobDBImpl(const std::string& dbname,
const BlobDBOptions& blob_db_options,
const DBOptions& db_options,
@ -114,7 +83,6 @@ BlobDBImpl::BlobDBImpl(const std::string& dbname,
next_file_number_(1),
epoch_of_(0),
shutdown_(false),
current_epoch_(0),
open_file_count_(0),
total_blob_space_(0),
open_p1_done_(false),
@ -181,10 +149,6 @@ Status BlobDBImpl::Open(std::vector<ColumnFamilyHandle*>* handles) {
// Update options
db_options_.listeners.push_back(
std::shared_ptr<EventListener>(new BlobDBFlushBeginListener(this)));
if (bdb_options_.enable_garbage_collection) {
db_options_.listeners.push_back(std::shared_ptr<EventListener>(
new EvictAllVersionsCompactionListener(this)));
}
cf_options_.compaction_filter_factory.reset(
new BlobIndexCompactionFilterFactory(env_, statistics_));
@ -214,14 +178,6 @@ void BlobDBImpl::StartBackgroundTasks() {
tqueue_.add(static_cast<int64_t>(
bdb_options_.garbage_collection_interval_secs * 1000),
std::bind(&BlobDBImpl::RunGC, this, std::placeholders::_1));
if (bdb_options_.enable_garbage_collection) {
tqueue_.add(
kDeleteCheckPeriodMillisecs,
std::bind(&BlobDBImpl::EvictDeletions, this, std::placeholders::_1));
tqueue_.add(
kDeleteCheckPeriodMillisecs,
std::bind(&BlobDBImpl::EvictCompacted, this, std::placeholders::_1));
}
tqueue_.add(
kDeleteObsoleteFilesPeriodMillisecs,
std::bind(&BlobDBImpl::DeleteObsoleteFiles, this, std::placeholders::_1));
@ -298,12 +254,6 @@ Status BlobDBImpl::OpenAllBlobFiles() {
return read_metadata_status;
}
// since this file already existed, we will try to reconcile
// deleted count with LSM
if (bdb_options_.enable_garbage_collection) {
blob_file->gc_once_after_open_ = true;
}
blob_files_[file_number] = blob_file;
if (!blob_file_list.empty()) {
blob_file_list.append(", ");
@ -553,17 +503,6 @@ std::shared_ptr<BlobFile> BlobDBImpl::SelectBlobFileTTL(uint64_t expiration) {
return bfile;
}
Status BlobDBImpl::Delete(const WriteOptions& options, const Slice& key) {
SequenceNumber lsn = db_impl_->GetLatestSequenceNumber();
Status s = db_->Delete(options, key);
if (bdb_options_.enable_garbage_collection) {
// add deleted key to list of keys that have been deleted for book-keeping
delete_keys_q_.enqueue({DefaultColumnFamily(), key.ToString(), lsn});
}
return s;
}
class BlobDBImpl::BlobInserter : public WriteBatch::Handler {
private:
const WriteOptions& options_;
@ -646,47 +585,7 @@ Status BlobDBImpl::Write(const WriteOptions& options, WriteBatch* updates) {
if (!s.ok()) {
return s;
}
s = db_->Write(options, blob_inserter.batch());
if (!s.ok()) {
return s;
}
// add deleted key to list of keys that have been deleted for book-keeping
class DeleteBookkeeper : public WriteBatch::Handler {
public:
explicit DeleteBookkeeper(BlobDBImpl* impl, const SequenceNumber& seq)
: impl_(impl), sequence_(seq) {}
virtual Status PutCF(uint32_t /*column_family_id*/, const Slice& /*key*/,
const Slice& /*value*/) override {
sequence_++;
return Status::OK();
}
virtual Status DeleteCF(uint32_t column_family_id,
const Slice& key) override {
ColumnFamilyHandle* cfh =
impl_->db_impl_->GetColumnFamilyHandleUnlocked(column_family_id);
impl_->delete_keys_q_.enqueue({cfh, key.ToString(), sequence_});
sequence_++;
return Status::OK();
}
private:
BlobDBImpl* impl_;
SequenceNumber sequence_;
};
if (bdb_options_.enable_garbage_collection) {
// add deleted key to list of keys that have been deleted for book-keeping
SequenceNumber current_seq =
WriteBatchInternal::Sequence(blob_inserter.batch());
DeleteBookkeeper delete_bookkeeper(this, current_seq);
s = updates->Iterate(&delete_bookkeeper);
}
return s;
return db_->Write(options, blob_inserter.batch());
}
Status BlobDBImpl::GetLiveFiles(std::vector<std::string>& ret,
@ -1204,10 +1103,8 @@ std::pair<bool, int64_t> BlobDBImpl::SanityCheck(bool aborted) {
for (auto bfile_pair : blob_files_) {
auto bfile = bfile_pair.second;
ROCKS_LOG_INFO(
db_options_.info_log,
"Blob File %s %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64,
db_options_.info_log, "Blob File %s %" PRIu64 " %" PRIu64 " %" PRIu64,
bfile->PathName().c_str(), bfile->GetFileSize(), bfile->BlobCount(),
bfile->deleted_count_, bfile->deleted_size_,
(bfile->expiration_range_.second - epoch_now));
}
@ -1281,136 +1178,6 @@ bool BlobDBImpl::VisibleToActiveSnapshot(
return oldest_snapshot < obsolete_sequence;
}
bool BlobDBImpl::FindFileAndEvictABlob(uint64_t file_number, uint64_t key_size,
uint64_t blob_offset,
uint64_t blob_size) {
assert(bdb_options_.enable_garbage_collection);
(void)blob_offset;
std::shared_ptr<BlobFile> bfile;
{
ReadLock rl(&mutex_);
auto hitr = blob_files_.find(file_number);
// file was deleted
if (hitr == blob_files_.end()) {
return false;
}
bfile = hitr->second;
}
WriteLock lockbfile_w(&bfile->mutex_);
bfile->deleted_count_++;
bfile->deleted_size_ += key_size + blob_size + BlobLogRecord::kHeaderSize;
return true;
}
bool BlobDBImpl::MarkBlobDeleted(const Slice& key, const Slice& index_entry) {
assert(bdb_options_.enable_garbage_collection);
BlobIndex blob_index;
Status s = blob_index.DecodeFrom(index_entry);
if (!s.ok()) {
ROCKS_LOG_INFO(db_options_.info_log,
"Could not parse lsm val in MarkBlobDeleted %s",
index_entry.ToString().c_str());
return false;
}
bool succ = FindFileAndEvictABlob(blob_index.file_number(), key.size(),
blob_index.offset(), blob_index.size());
return succ;
}
std::pair<bool, int64_t> BlobDBImpl::EvictCompacted(bool aborted) {
assert(bdb_options_.enable_garbage_collection);
if (aborted) return std::make_pair(false, -1);
override_packet_t packet;
size_t total_vals = 0;
size_t mark_evicted = 0;
while (override_vals_q_.dequeue(&packet)) {
bool succeeded =
FindFileAndEvictABlob(packet.file_number_, packet.key_size_,
packet.blob_offset_, packet.blob_size_);
total_vals++;
if (succeeded) {
mark_evicted++;
}
}
ROCKS_LOG_INFO(db_options_.info_log,
"Mark %" ROCKSDB_PRIszt
" values to evict, out of %" ROCKSDB_PRIszt
" compacted values.",
mark_evicted, total_vals);
return std::make_pair(true, -1);
}
std::pair<bool, int64_t> BlobDBImpl::EvictDeletions(bool aborted) {
assert(bdb_options_.enable_garbage_collection);
if (aborted) return std::make_pair(false, -1);
ColumnFamilyHandle* last_cfh = nullptr;
Options last_op;
Arena arena;
ScopedArenaIterator iter;
// we will use same RangeDelAggregator for all cf's.
// essentially we do not support Range Deletes now
std::unique_ptr<RangeDelAggregator> range_del_agg;
delete_packet_t dpacket;
while (delete_keys_q_.dequeue(&dpacket)) {
if (last_cfh != dpacket.cfh_) {
if (!range_del_agg) {
auto cfhi = reinterpret_cast<ColumnFamilyHandleImpl*>(dpacket.cfh_);
auto cfd = cfhi->cfd();
range_del_agg.reset(new RangeDelAggregator(cfd->internal_comparator(),
kMaxSequenceNumber));
}
// this can be expensive
last_cfh = dpacket.cfh_;
last_op = db_impl_->GetOptions(last_cfh);
iter.set(db_impl_->NewInternalIterator(&arena, range_del_agg.get(),
dpacket.cfh_));
// this will not work for multiple CF's.
}
Slice user_key(dpacket.key_);
InternalKey target(user_key, dpacket.dsn_, kTypeValue);
Slice eslice = target.Encode();
iter->Seek(eslice);
if (!iter->status().ok()) {
ROCKS_LOG_INFO(db_options_.info_log, "Invalid iterator seek %s",
dpacket.key_.c_str());
continue;
}
const Comparator* bwc = BytewiseComparator();
while (iter->Valid()) {
if (!bwc->Equal(ExtractUserKey(iter->key()), ExtractUserKey(eslice)))
break;
ParsedInternalKey ikey(Slice(), 0, kTypeValue);
if (!ParseInternalKey(iter->key(), &ikey)) {
continue;
}
// once you hit a DELETE, assume the keys below have been
// processed previously
if (ikey.type == kTypeDeletion || ikey.type == kTypeSingleDeletion) break;
Slice val = iter->value();
MarkBlobDeleted(ikey.user_key, val);
iter->Next();
}
}
return std::make_pair(true, -1);
}
std::pair<bool, int64_t> BlobDBImpl::CheckSeqFiles(bool aborted) {
if (aborted) return std::make_pair(false, -1);
@ -1572,8 +1339,6 @@ Status BlobDBImpl::GCFileAndUpdateLSM(const std::shared_ptr<BlobFile>& bfptr,
return s;
}
bool first_gc = bfptr->gc_once_after_open_;
auto* cfh =
db_impl_->GetColumnFamilyHandleUnlocked(bfptr->column_family_id());
auto* cfd = reinterpret_cast<ColumnFamilyHandleImpl*>(cfh)->cfd();
@ -1583,19 +1348,9 @@ Status BlobDBImpl::GCFileAndUpdateLSM(const std::shared_ptr<BlobFile>& bfptr,
// this reads the key but skips the blob
Reader::ReadLevel shallow = Reader::kReadHeaderKey;
bool no_relocation_ttl =
(has_ttl && now >= bfptr->GetExpirationRange().second);
bool file_expired = has_ttl && now >= bfptr->GetExpirationRange().second;
bool no_relocation_lsmdel = false;
{
ReadLock lockbfile_r(&bfptr->mutex_);
no_relocation_lsmdel =
(bfptr->GetFileSize() ==
(BlobLogHeader::kSize + bfptr->deleted_size_ + BlobLogFooter::kSize));
}
bool no_relocation = no_relocation_ttl || no_relocation_lsmdel;
if (!no_relocation) {
if (!file_expired) {
// read the blob because you have to write it back to new file
shallow = Reader::kReadHeaderKeyBlob;
}
@ -1671,7 +1426,7 @@ Status BlobDBImpl::GCFileAndUpdateLSM(const std::shared_ptr<BlobFile>& bfptr,
// If key has expired, remove it from base DB.
// TODO(yiwu): Blob indexes will be remove by BlobIndexCompactionFilter.
// We can just drop the blob record.
if (no_relocation_ttl || (has_ttl && now >= record.expiration)) {
if (file_expired || (has_ttl && now >= record.expiration)) {
gc_stats->num_keys_expired++;
gc_stats->bytes_expired += record.record_size();
TEST_SYNC_POINT("BlobDBImpl::GCFileAndUpdateLSM:BeforeDelete");
@ -1693,11 +1448,6 @@ Status BlobDBImpl::GCFileAndUpdateLSM(const std::shared_ptr<BlobFile>& bfptr,
continue;
}
if (first_gc) {
// Do not relocate blob record for initial GC.
continue;
}
// Relocate the blob record to new file.
if (!newfile) {
// new file
@ -1765,7 +1515,7 @@ Status BlobDBImpl::GCFileAndUpdateLSM(const std::shared_ptr<BlobFile>& bfptr,
if (s.ok()) {
bfptr->MarkObsolete(GetLatestSequenceNumber());
if (!first_gc) {
{
WriteLock wl(&mutex_);
obsolete_files_.push_back(bfptr);
}
@ -1806,73 +1556,6 @@ Status BlobDBImpl::GCFileAndUpdateLSM(const std::shared_ptr<BlobFile>& bfptr,
return s;
}
// Ideally we should hold the lock during the entire function,
// but under the asusmption that this is only called when a
// file is Immutable, we can reduce the critical section
bool BlobDBImpl::ShouldGCFile(std::shared_ptr<BlobFile> bfile, uint64_t now,
bool is_oldest_non_ttl_file,
std::string* reason) {
if (bfile->HasTTL()) {
ExpirationRange expiration_range = bfile->GetExpirationRange();
if (now > expiration_range.second) {
*reason = "entire file ttl expired";
return true;
}
if (!bfile->file_size_.load()) {
ROCKS_LOG_ERROR(db_options_.info_log, "Invalid file size = 0 %s",
bfile->PathName().c_str());
*reason = "file is empty";
return false;
}
if (bfile->gc_once_after_open_.load()) {
return true;
}
ReadLock lockbfile_r(&bfile->mutex_);
bool ret = ((bfile->deleted_size_ / bfile->file_size_.load()) >
bdb_options_.garbage_collection_deletion_size_threshold);
if (ret) {
*reason = "deleted blobs beyond threshold";
} else {
*reason = "deleted blobs below threshold";
}
return ret;
}
// when crash happens, we lose the in-memory account of deleted blobs.
// we are therefore forced to do one GC to make sure delete accounting
// is OK
if (bfile->gc_once_after_open_.load()) {
return true;
}
ReadLock lockbfile_r(&bfile->mutex_);
if (bdb_options_.enable_garbage_collection) {
if ((bfile->deleted_size_ / bfile->file_size_.load()) >
bdb_options_.garbage_collection_deletion_size_threshold) {
*reason = "deleted simple blobs beyond threshold";
return true;
}
}
// if we haven't reached limits of disk space, don't DELETE
if (bdb_options_.blob_dir_size == 0 ||
total_blob_space_.load() < bdb_options_.blob_dir_size) {
*reason = "disk space not exceeded";
return false;
}
if (is_oldest_non_ttl_file) {
*reason = "out of space and is the oldest simple blob file";
return true;
}
*reason = "out of space but is not the oldest simple blob file";
return false;
}
std::pair<bool, int64_t> BlobDBImpl::DeleteObsoleteFiles(bool aborted) {
if (aborted) return std::make_pair(false, -1);
@ -1958,98 +1641,13 @@ void BlobDBImpl::CopyBlobFiles(
}
}
void BlobDBImpl::FilterSubsetOfFiles(
const std::vector<std::shared_ptr<BlobFile>>& blob_files,
std::vector<std::shared_ptr<BlobFile>>* to_process, uint64_t epoch,
size_t files_to_collect) {
// 100.0 / 15.0 = 7
uint64_t next_epoch_increment = static_cast<uint64_t>(
std::ceil(100 / static_cast<double>(kGCFilePercentage)));
uint64_t now = EpochNow();
size_t files_processed = 0;
bool non_ttl_file_found = false;
for (auto bfile : blob_files) {
if (files_processed >= files_to_collect) break;
// if this is the first time processing the file
// i.e. gc_epoch == -1, process it.
// else process the file if its processing epoch matches
// the current epoch. Typically the #of epochs should be
// around 5-10
if (bfile->gc_epoch_ != -1 && (uint64_t)bfile->gc_epoch_ != epoch) {
continue;
}
files_processed++;
// reset the epoch
bfile->gc_epoch_ = epoch + next_epoch_increment;
// file has already been GC'd or is still open for append,
// then it should not be GC'd
if (bfile->Obsolete() || !bfile->Immutable()) continue;
bool is_oldest_non_ttl_file = false;
if (!non_ttl_file_found && !bfile->HasTTL()) {
is_oldest_non_ttl_file = true;
non_ttl_file_found = true;
}
std::string reason;
bool shouldgc = ShouldGCFile(bfile, now, is_oldest_non_ttl_file, &reason);
if (!shouldgc) {
ROCKS_LOG_DEBUG(db_options_.info_log,
"File has been skipped for GC ttl %s %" PRIu64 " %" PRIu64
" reason='%s'",
bfile->PathName().c_str(), now,
bfile->GetExpirationRange().second, reason.c_str());
continue;
}
ROCKS_LOG_INFO(db_options_.info_log,
"File has been chosen for GC ttl %s %" PRIu64 " %" PRIu64
" reason='%s'",
bfile->PathName().c_str(), now,
bfile->GetExpirationRange().second, reason.c_str());
to_process->push_back(bfile);
}
}
std::pair<bool, int64_t> BlobDBImpl::RunGC(bool aborted) {
if (aborted) return std::make_pair(false, -1);
current_epoch_++;
std::vector<std::shared_ptr<BlobFile>> blob_files;
CopyBlobFiles(&blob_files);
if (!blob_files.size()) return std::make_pair(true, -1);
// 15% of files are collected each call to space out the IO and CPU
// consumption.
size_t files_to_collect = (kGCFilePercentage * blob_files.size()) / 100;
std::vector<std::shared_ptr<BlobFile>> to_process;
FilterSubsetOfFiles(blob_files, &to_process, current_epoch_,
files_to_collect);
for (auto bfile : to_process) {
GCStats gc_stats;
Status s = GCFileAndUpdateLSM(bfile, &gc_stats);
if (!s.ok()) {
continue;
}
if (bfile->gc_once_after_open_.load()) {
WriteLock lockbfile_w(&bfile->mutex_);
bfile->deleted_size_ =
gc_stats.bytes_overwritten + gc_stats.bytes_expired;
bfile->deleted_count_ =
gc_stats.num_keys_overwritten + gc_stats.num_keys_expired;
bfile->gc_once_after_open_ = false;
}
if (aborted) {
return std::make_pair(false, -1);
}
// TODO(yiwu): Garbage collection implementation.
// reschedule
return std::make_pair(true, -1);
}

85
utilities/blob_db/blob_db_impl.h
View File

@ -26,7 +26,6 @@
#include "rocksdb/options.h"
#include "rocksdb/statistics.h"
#include "rocksdb/wal_filter.h"
#include "util/mpsc.h"
#include "util/mutexlock.h"
#include "util/timer_queue.h"
#include "utilities/blob_db/blob_db.h"
@ -73,34 +72,6 @@ class BlobReconcileWalFilter : public WalFilter {
virtual const char* Name() const override { return "BlobDBWalReconciler"; }
};
class EvictAllVersionsCompactionListener : public EventListener {
public:
class InternalListener : public CompactionEventListener {
friend class BlobDBImpl;
public:
explicit InternalListener(BlobDBImpl* blob_db_impl) : impl_(blob_db_impl) {}
virtual void OnCompaction(int level, const Slice& key,
CompactionListenerValueType value_type,
const Slice& existing_value,
const SequenceNumber& sn, bool is_new) override;
private:
BlobDBImpl* impl_;
};
explicit EvictAllVersionsCompactionListener(BlobDBImpl* blob_db_impl)
: internal_listener_(new InternalListener(blob_db_impl)) {}
virtual CompactionEventListener* GetCompactionEventListener() override {
return internal_listener_.get();
}
private:
std::unique_ptr<InternalListener> internal_listener_;
};
// Comparator to sort "TTL" aware Blob files based on the lower value of
// TTL range.
struct blobf_compare_ttl {
@ -124,7 +95,6 @@ struct GCStats {
* Garbage Collected.
*/
class BlobDBImpl : public BlobDB {
friend class EvictAllVersionsCompactionListener;
friend class BlobFile;
friend class BlobDBIterator;
@ -161,9 +131,6 @@ class BlobDBImpl : public BlobDB {
Status Put(const WriteOptions& options, const Slice& key,
const Slice& value) override;
using BlobDB::Delete;
Status Delete(const WriteOptions& options, const Slice& key) override;
using BlobDB::Get;
Status Get(const ReadOptions& read_options, ColumnFamilyHandle* column_family,
const Slice& key, PinnableSlice* value) override;
@ -249,13 +216,6 @@ class BlobDBImpl : public BlobDB {
Slice GetCompressedSlice(const Slice& raw,
std::string* compression_output) const;
// is this file ready for Garbage collection. if the TTL of the file
// has expired or if threshold of the file has been evicted
// tt - current time
// last_id - the id of the non-TTL file to evict
bool ShouldGCFile(std::shared_ptr<BlobFile> bfile, uint64_t now,
bool is_oldest_non_ttl_file, std::string* reason);
// Close a file by appending a footer, and removes file from open files list.
Status CloseBlobFile(std::shared_ptr<BlobFile> bfile);
@ -305,11 +265,6 @@ class BlobDBImpl : public BlobDB {
// efficiency
std::pair<bool, int64_t> ReclaimOpenFiles(bool aborted);
// background task to do book-keeping of deleted keys
std::pair<bool, int64_t> EvictDeletions(bool aborted);
std::pair<bool, int64_t> EvictCompacted(bool aborted);
std::pair<bool, int64_t> RemoveTimerQ(TimerQueue* tq, bool aborted);
// Adds the background tasks to the timer queue
@ -354,20 +309,10 @@ class BlobDBImpl : public BlobDB {
bool VisibleToActiveSnapshot(const std::shared_ptr<BlobFile>& file);
bool FileDeleteOk_SnapshotCheckLocked(const std::shared_ptr<BlobFile>& bfile);
bool MarkBlobDeleted(const Slice& key, const Slice& lsmValue);
bool FindFileAndEvictABlob(uint64_t file_number, uint64_t key_size,
uint64_t blob_offset, uint64_t blob_size);
void CopyBlobFiles(
std::vector<std::shared_ptr<BlobFile>>* bfiles_copy,
std::function<bool(const std::shared_ptr<BlobFile>&)> predicate = {});
void FilterSubsetOfFiles(
const std::vector<std::shared_ptr<BlobFile>>& blob_files,
std::vector<std::shared_ptr<BlobFile>>* to_process, uint64_t epoch,
size_t files_to_collect);
uint64_t EpochNow() { return env_->NowMicros() / 1000000; }
Status CheckSize(size_t blob_size);
@ -423,42 +368,12 @@ class BlobDBImpl : public BlobDB {
// on variety of incoming TTL's
std::multiset<std::shared_ptr<BlobFile>, blobf_compare_ttl> open_ttl_files_;
// packet of information to put in lockess delete(s) queue
struct delete_packet_t {
ColumnFamilyHandle* cfh_;
std::string key_;
SequenceNumber dsn_;
};
struct override_packet_t {
uint64_t file_number_;
uint64_t key_size_;
uint64_t blob_offset_;
uint64_t blob_size_;
SequenceNumber dsn_;
};
// LOCKLESS multiple producer single consumer queue to quickly append
// deletes without taking lock. Can rapidly grow in size!!
// deletes happen in LSM, but minor book-keeping needs to happen on
// BLOB side (for triggering eviction)
mpsc_queue_t<delete_packet_t> delete_keys_q_;
// LOCKLESS multiple producer single consumer queue for values
// that are being compacted
mpsc_queue_t<override_packet_t> override_vals_q_;
// atomic bool to represent shutdown
std::atomic<bool> shutdown_;
// timer based queue to execute tasks
TimerQueue tqueue_;
// only accessed in GC thread, hence not atomic. The epoch of the
// GC task. Each execution is one epoch. Helps us in allocating
// files to one execution
uint64_t current_epoch_;
// number of files opened for random access/GET
// counter is used to monitor and close excess RA files.
std::atomic<uint32_t> open_file_count_;

26
utilities/blob_db/blob_file.cc
View File

@ -35,13 +35,9 @@ BlobFile::BlobFile()
compression_(kNoCompression),
has_ttl_(false),
blob_count_(0),
gc_epoch_(-1),
file_size_(0),
deleted_count_(0),
deleted_size_(0),
closed_(false),
obsolete_(false),
gc_once_after_open_(false),
expiration_range_({0, 0}),
last_access_(-1),
last_fsync_(0),
@ -58,13 +54,9 @@ BlobFile::BlobFile(const BlobDBImpl* p, const std::string& bdir, uint64_t fn,
compression_(kNoCompression),
has_ttl_(false),
blob_count_(0),
gc_epoch_(-1),
file_size_(0),
deleted_count_(0),
deleted_size_(0),
closed_(false),
obsolete_(false),
gc_once_after_open_(false),
expiration_range_({0, 0}),
last_access_(-1),
last_fsync_(0),
@ -109,16 +101,14 @@ std::shared_ptr<Reader> BlobFile::OpenSequentialReader(
std::string BlobFile::DumpState() const {
char str[1000];
snprintf(str, sizeof(str),
"path: %s fn: %" PRIu64 " blob_count: %" PRIu64 " gc_epoch: %" PRIu64
" file_size: %" PRIu64 " deleted_count: %" PRIu64
" deleted_size: %" PRIu64
" closed: %d obsolete: %d expiration_range: (%" PRIu64 ", %" PRIu64
"), writer: %d reader: %d",
path_to_dir_.c_str(), file_number_, blob_count_.load(),
gc_epoch_.load(), file_size_.load(), deleted_count_, deleted_size_,
closed_.load(), obsolete_.load(), expiration_range_.first,
expiration_range_.second, (!!log_writer_), (!!ra_file_reader_));
snprintf(
str, sizeof(str),
"path: %s fn: %" PRIu64 " blob_count: %" PRIu64 " file_size: %" PRIu64
" closed: %d obsolete: %d expiration_range: (%" PRIu64 ", %" PRIu64
"), writer: %d reader: %d",
path_to_dir_.c_str(), file_number_, blob_count_.load(), file_size_.load(),
closed_.load(), obsolete_.load(), expiration_range_.first,
expiration_range_.second, (!!log_writer_), (!!ra_file_reader_));
return str;
}

12
utilities/blob_db/blob_file.h
View File

@ -53,18 +53,9 @@ class BlobFile {
// number of blobs in the file
std::atomic<uint64_t> blob_count_;
// the file will be selected for GC in this future epoch
std::atomic<int64_t> gc_epoch_;
// size of the file
std::atomic<uint64_t> file_size_;
// number of blobs in this particular file which have been evicted
uint64_t deleted_count_;
// size of deleted blobs (used by heuristic to select file for GC)
uint64_t deleted_size_;
BlobLogHeader header_;
// closed_ = true implies the file is no more mutable
@ -79,9 +70,6 @@ class BlobFile {
// Data in this file is visible to a snapshot taken before the sequence.
SequenceNumber obsolete_sequence_;
// should this file been gc'd once to reconcile lost deletes/compactions
std::atomic<bool> gc_once_after_open_;
ExpirationRange expiration_range_;
// Sequential/Append writer for blobs