dolysis/rocksdb
3
0
Fork 0
mirror of https://github.com/facebook/rocksdb.git synced 2024-11-26 07:30:54 +00:00
Code Issues Packages Projects Releases Wiki Activity
rocksdb/table/get_context.cc
chuhao zeng 8acf17002a Fix row cache falsely return kNotFound when timestamp enabled (#11816) 
Summary:
**Summary:**
When row cache hits and a timestamp is being set in read_options, even though ROW_CACHE entry is hit, the return status is kNotFound.

**Cause of error:**
If timestamp is provided in readoptions, a callback for sequence number checking is registered [here](8fc78a3a9e/db/db_impl/db_impl.cc (L2112)).

Hence the default value set at this [line](694e49cbb1/table/get_context.cc (L611)) prevents get_context from saving value found in cache. Causing the final status to be kNotFound even though the entry exist in both cache and SST file.

**Proposed Solution**
Row cache key contains a sequence number in it. If the key for row cache lookup matches the key in cache, this cache entry should be good to be exposed to user and hence we reuse the sequence number in cache key rather than passing kMaxSequenceNumber.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11816

Reviewed By: ajkr

Differential Revision: D49419029

Pulled By: jowlyzhang

fbshipit-source-id: 6c77e9e751628d7d8e6c389f299e29a11ea824c6
2023-09-20 11:34:38 -07:00

580 lines
22 KiB
C++
Raw Blame History

// 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).
#include "table/get_context.h"
#include "db/blob//blob_fetcher.h"
#include "db/merge_helper.h"
#include "db/pinned_iterators_manager.h"
#include "db/read_callback.h"
#include "db/wide/wide_column_serialization.h"
#include "monitoring/file_read_sample.h"
#include "monitoring/perf_context_imp.h"
#include "monitoring/statistics_impl.h"
#include "rocksdb/merge_operator.h"
#include "rocksdb/statistics.h"
#include "rocksdb/system_clock.h"
namespace ROCKSDB_NAMESPACE {
namespace {
void appendToReplayLog(std::string* replay_log, ValueType type, Slice value) {
if (replay_log) {
if (replay_log->empty()) {
// Optimization: in the common case of only one operation in the
// log, we allocate the exact amount of space needed.
replay_log->reserve(1 + VarintLength(value.size()) + value.size());
}
replay_log->push_back(type);
PutLengthPrefixedSlice(replay_log, value);
}
}
} // namespace
GetContext::GetContext(
const Comparator* ucmp, const MergeOperator* merge_operator, Logger* logger,
Statistics* statistics, GetState init_state, const Slice& user_key,
PinnableSlice* pinnable_val, PinnableWideColumns* columns,
std::string* timestamp, bool* value_found, MergeContext* merge_context,
bool do_merge, SequenceNumber* _max_covering_tombstone_seq,
SystemClock* clock, SequenceNumber* seq,
PinnedIteratorsManager* _pinned_iters_mgr, ReadCallback* callback,
bool* is_blob_index, uint64_t tracing_get_id, BlobFetcher* blob_fetcher)
: ucmp_(ucmp),
merge_operator_(merge_operator),
logger_(logger),
statistics_(statistics),
state_(init_state),
user_key_(user_key),
pinnable_val_(pinnable_val),
columns_(columns),
timestamp_(timestamp),
value_found_(value_found),
merge_context_(merge_context),
max_covering_tombstone_seq_(_max_covering_tombstone_seq),
clock_(clock),
seq_(seq),
replay_log_(nullptr),
pinned_iters_mgr_(_pinned_iters_mgr),
callback_(callback),
do_merge_(do_merge),
is_blob_index_(is_blob_index),
tracing_get_id_(tracing_get_id),
blob_fetcher_(blob_fetcher) {
if (seq_) {
*seq_ = kMaxSequenceNumber;
}
sample_ = should_sample_file_read();
}
GetContext::GetContext(const Comparator* ucmp,
const MergeOperator* merge_operator, Logger* logger,
Statistics* statistics, GetState init_state,
const Slice& user_key, PinnableSlice* pinnable_val,
PinnableWideColumns* columns, bool* value_found,
MergeContext* merge_context, bool do_merge,
SequenceNumber* _max_covering_tombstone_seq,
SystemClock* clock, SequenceNumber* seq,
PinnedIteratorsManager* _pinned_iters_mgr,
ReadCallback* callback, bool* is_blob_index,
uint64_t tracing_get_id, BlobFetcher* blob_fetcher)
: GetContext(ucmp, merge_operator, logger, statistics, init_state, user_key,
pinnable_val, columns, /*timestamp=*/nullptr, value_found,
merge_context, do_merge, _max_covering_tombstone_seq, clock,
seq, _pinned_iters_mgr, callback, is_blob_index,
tracing_get_id, blob_fetcher) {}
// Called from TableCache::Get and Table::Get when file/block in which
// key may exist are not there in TableCache/BlockCache respectively. In this
// case we can't guarantee that key does not exist and are not permitted to do
// IO to be certain.Set the status=kFound and value_found=false to let the
// caller know that key may exist but is not there in memory
void GetContext::MarkKeyMayExist() {
state_ = kFound;
if (value_found_ != nullptr) {
*value_found_ = false;
}
}
void GetContext::SaveValue(const Slice& value, SequenceNumber /*seq*/) {
assert(state_ == kNotFound);
appendToReplayLog(replay_log_, kTypeValue, value);
state_ = kFound;
if (LIKELY(pinnable_val_ != nullptr)) {
pinnable_val_->PinSelf(value);
}
}
void GetContext::ReportCounters() {
if (get_context_stats_.num_cache_hit > 0) {
RecordTick(statistics_, BLOCK_CACHE_HIT, get_context_stats_.num_cache_hit);
}
if (get_context_stats_.num_cache_index_hit > 0) {
RecordTick(statistics_, BLOCK_CACHE_INDEX_HIT,
get_context_stats_.num_cache_index_hit);
}
if (get_context_stats_.num_cache_data_hit > 0) {
RecordTick(statistics_, BLOCK_CACHE_DATA_HIT,
get_context_stats_.num_cache_data_hit);
}
if (get_context_stats_.num_cache_filter_hit > 0) {
RecordTick(statistics_, BLOCK_CACHE_FILTER_HIT,
get_context_stats_.num_cache_filter_hit);
}
if (get_context_stats_.num_cache_compression_dict_hit > 0) {
RecordTick(statistics_, BLOCK_CACHE_COMPRESSION_DICT_HIT,
get_context_stats_.num_cache_compression_dict_hit);
}
if (get_context_stats_.num_cache_index_miss > 0) {
RecordTick(statistics_, BLOCK_CACHE_INDEX_MISS,
get_context_stats_.num_cache_index_miss);
}
if (get_context_stats_.num_cache_filter_miss > 0) {
RecordTick(statistics_, BLOCK_CACHE_FILTER_MISS,
get_context_stats_.num_cache_filter_miss);
}
if (get_context_stats_.num_cache_data_miss > 0) {
RecordTick(statistics_, BLOCK_CACHE_DATA_MISS,
get_context_stats_.num_cache_data_miss);
}
if (get_context_stats_.num_cache_compression_dict_miss > 0) {
RecordTick(statistics_, BLOCK_CACHE_COMPRESSION_DICT_MISS,
get_context_stats_.num_cache_compression_dict_miss);
}
if (get_context_stats_.num_cache_bytes_read > 0) {
RecordTick(statistics_, BLOCK_CACHE_BYTES_READ,
get_context_stats_.num_cache_bytes_read);
}
if (get_context_stats_.num_cache_miss > 0) {
RecordTick(statistics_, BLOCK_CACHE_MISS,
get_context_stats_.num_cache_miss);
}
if (get_context_stats_.num_cache_add > 0) {
RecordTick(statistics_, BLOCK_CACHE_ADD, get_context_stats_.num_cache_add);
}
if (get_context_stats_.num_cache_add_redundant > 0) {
RecordTick(statistics_, BLOCK_CACHE_ADD_REDUNDANT,
get_context_stats_.num_cache_add_redundant);
}
if (get_context_stats_.num_cache_bytes_write > 0) {
RecordTick(statistics_, BLOCK_CACHE_BYTES_WRITE,
get_context_stats_.num_cache_bytes_write);
}
if (get_context_stats_.num_cache_index_add > 0) {
RecordTick(statistics_, BLOCK_CACHE_INDEX_ADD,
get_context_stats_.num_cache_index_add);
}
if (get_context_stats_.num_cache_index_add_redundant > 0) {
RecordTick(statistics_, BLOCK_CACHE_INDEX_ADD_REDUNDANT,
get_context_stats_.num_cache_index_add_redundant);
}
if (get_context_stats_.num_cache_index_bytes_insert > 0) {
RecordTick(statistics_, BLOCK_CACHE_INDEX_BYTES_INSERT,
get_context_stats_.num_cache_index_bytes_insert);
}
if (get_context_stats_.num_cache_data_add > 0) {
RecordTick(statistics_, BLOCK_CACHE_DATA_ADD,
get_context_stats_.num_cache_data_add);
}
if (get_context_stats_.num_cache_data_add_redundant > 0) {
RecordTick(statistics_, BLOCK_CACHE_DATA_ADD_REDUNDANT,
get_context_stats_.num_cache_data_add_redundant);
}
if (get_context_stats_.num_cache_data_bytes_insert > 0) {
RecordTick(statistics_, BLOCK_CACHE_DATA_BYTES_INSERT,
get_context_stats_.num_cache_data_bytes_insert);
}
if (get_context_stats_.num_cache_filter_add > 0) {
RecordTick(statistics_, BLOCK_CACHE_FILTER_ADD,
get_context_stats_.num_cache_filter_add);
}
if (get_context_stats_.num_cache_filter_add_redundant > 0) {
RecordTick(statistics_, BLOCK_CACHE_FILTER_ADD_REDUNDANT,
get_context_stats_.num_cache_filter_add_redundant);
}
if (get_context_stats_.num_cache_filter_bytes_insert > 0) {
RecordTick(statistics_, BLOCK_CACHE_FILTER_BYTES_INSERT,
get_context_stats_.num_cache_filter_bytes_insert);
}
if (get_context_stats_.num_cache_compression_dict_add > 0) {
RecordTick(statistics_, BLOCK_CACHE_COMPRESSION_DICT_ADD,
get_context_stats_.num_cache_compression_dict_add);
}
if (get_context_stats_.num_cache_compression_dict_add_redundant > 0) {
RecordTick(statistics_, BLOCK_CACHE_COMPRESSION_DICT_ADD_REDUNDANT,
get_context_stats_.num_cache_compression_dict_add_redundant);
}
if (get_context_stats_.num_cache_compression_dict_bytes_insert > 0) {
RecordTick(statistics_, BLOCK_CACHE_COMPRESSION_DICT_BYTES_INSERT,
get_context_stats_.num_cache_compression_dict_bytes_insert);
}
}
bool GetContext::SaveValue(const ParsedInternalKey& parsed_key,
const Slice& value, bool* matched,
Cleanable* value_pinner) {
assert(matched);
assert((state_ != kMerge && parsed_key.type != kTypeMerge) ||
merge_context_ != nullptr);
if (ucmp_->EqualWithoutTimestamp(parsed_key.user_key, user_key_)) {
*matched = true;
// If the value is not in the snapshot, skip it
if (!CheckCallback(parsed_key.sequence)) {
return true; // to continue to the next seq
}
appendToReplayLog(replay_log_, parsed_key.type, value);
if (seq_ != nullptr) {
// Set the sequence number if it is uninitialized
if (*seq_ == kMaxSequenceNumber) {
*seq_ = parsed_key.sequence;
}
if (max_covering_tombstone_seq_) {
*seq_ = std::max(*seq_, *max_covering_tombstone_seq_);
}
}
size_t ts_sz = ucmp_->timestamp_size();
if (ts_sz > 0 && timestamp_ != nullptr) {
if (!timestamp_->empty()) {
assert(ts_sz == timestamp_->size());
// `timestamp` can be set before `SaveValue` is ever called
// when max_covering_tombstone_seq_ was set.
// If this key has a higher sequence number than range tombstone,
// then timestamp should be updated. `ts_from_rangetombstone_` is
// set to false afterwards so that only the key with highest seqno
// updates the timestamp.
if (ts_from_rangetombstone_) {
assert(max_covering_tombstone_seq_);
if (parsed_key.sequence > *max_covering_tombstone_seq_) {
Slice ts = ExtractTimestampFromUserKey(parsed_key.user_key, ts_sz);
timestamp_->assign(ts.data(), ts.size());
ts_from_rangetombstone_ = false;
}
}
}
// TODO optimize for small size ts
const std::string kMaxTs(ts_sz, '\xff');
if (timestamp_->empty() ||
ucmp_->CompareTimestamp(*timestamp_, kMaxTs) == 0) {
Slice ts = ExtractTimestampFromUserKey(parsed_key.user_key, ts_sz);
timestamp_->assign(ts.data(), ts.size());
}
}
auto type = parsed_key.type;
// Key matches. Process it
if ((type == kTypeValue || type == kTypeMerge || type == kTypeBlobIndex ||
type == kTypeWideColumnEntity || type == kTypeDeletion ||
type == kTypeDeletionWithTimestamp || type == kTypeSingleDeletion) &&
max_covering_tombstone_seq_ != nullptr &&
*max_covering_tombstone_seq_ > parsed_key.sequence) {
// Note that deletion types are also considered, this is for the case
// when we need to return timestamp to user. If a range tombstone has a
// higher seqno than point tombstone, its timestamp should be returned.
type = kTypeRangeDeletion;
}
switch (type) {
case kTypeValue:
case kTypeBlobIndex:
case kTypeWideColumnEntity:
assert(state_ == kNotFound || state_ == kMerge);
if (type == kTypeBlobIndex) {
if (is_blob_index_ == nullptr) {
// Blob value not supported. Stop.
state_ = kUnexpectedBlobIndex;
return false;
}
}
if (is_blob_index_ != nullptr) {
*is_blob_index_ = (type == kTypeBlobIndex);
}
if (kNotFound == state_) {
state_ = kFound;
if (do_merge_) {
if (type == kTypeBlobIndex && ucmp_->timestamp_size() != 0) {
ukey_with_ts_found_.PinSelf(parsed_key.user_key);
}
if (LIKELY(pinnable_val_ != nullptr)) {
Slice value_to_use = value;
if (type == kTypeWideColumnEntity) {
Slice value_copy = value;
if (!WideColumnSerialization::GetValueOfDefaultColumn(
value_copy, value_to_use)
.ok()) {
state_ = kCorrupt;
return false;
}
}
if (LIKELY(value_pinner != nullptr)) {
// If the backing resources for the value are provided, pin them
pinnable_val_->PinSlice(value_to_use, value_pinner);
} else {
TEST_SYNC_POINT_CALLBACK("GetContext::SaveValue::PinSelf",
this);
// Otherwise copy the value
pinnable_val_->PinSelf(value_to_use);
}
} else if (columns_ != nullptr) {
if (type == kTypeWideColumnEntity) {
if (!columns_->SetWideColumnValue(value, value_pinner).ok()) {
state_ = kCorrupt;
return false;
}
} else {
columns_->SetPlainValue(value, value_pinner);
}
}
} else {
// It means this function is called as part of DB GetMergeOperands
// API and the current value should be part of
// merge_context_->operand_list
if (type == kTypeBlobIndex) {
PinnableSlice pin_val;
if (GetBlobValue(parsed_key.user_key, value, &pin_val) == false) {
return false;
}
Slice blob_value(pin_val);
push_operand(blob_value, nullptr);
} else if (type == kTypeWideColumnEntity) {
Slice value_copy = value;
Slice value_of_default;
if (!WideColumnSerialization::GetValueOfDefaultColumn(
value_copy, value_of_default)
.ok()) {
state_ = kCorrupt;
return false;
}
push_operand(value_of_default, value_pinner);
} else {
assert(type == kTypeValue);
push_operand(value, value_pinner);
}
}
} else if (kMerge == state_) {
assert(merge_operator_ != nullptr);
if (type == kTypeBlobIndex) {
PinnableSlice pin_val;
if (GetBlobValue(parsed_key.user_key, value, &pin_val) == false) {
return false;
}
Slice blob_value(pin_val);
state_ = kFound;
if (do_merge_) {
MergeWithPlainBaseValue(blob_value);
} else {
// It means this function is called as part of DB GetMergeOperands
// API and the current value should be part of
// merge_context_->operand_list
push_operand(blob_value, nullptr);
}
} else if (type == kTypeWideColumnEntity) {
state_ = kFound;
if (do_merge_) {
MergeWithWideColumnBaseValue(value);
} else {
// It means this function is called as part of DB GetMergeOperands
// API and the current value should be part of
// merge_context_->operand_list
Slice value_copy = value;
Slice value_of_default;
if (!WideColumnSerialization::GetValueOfDefaultColumn(
value_copy, value_of_default)
.ok()) {
state_ = kCorrupt;
return false;
}
push_operand(value_of_default, value_pinner);
}
} else {
assert(type == kTypeValue);
state_ = kFound;
if (do_merge_) {
MergeWithPlainBaseValue(value);
} else {
// It means this function is called as part of DB GetMergeOperands
// API and the current value should be part of
// merge_context_->operand_list
push_operand(value, value_pinner);
}
}
}
return false;
case kTypeDeletion:
case kTypeDeletionWithTimestamp:
case kTypeSingleDeletion:
case kTypeRangeDeletion:
// TODO(noetzli): Verify correctness once merge of single-deletes
// is supported
assert(state_ == kNotFound || state_ == kMerge);
if (kNotFound == state_) {
state_ = kDeleted;
} else if (kMerge == state_) {
state_ = kFound;
if (do_merge_) {
MergeWithNoBaseValue();
}
// If do_merge_ = false then the current value shouldn't be part of
// merge_context_->operand_list
}
return false;
case kTypeMerge:
assert(state_ == kNotFound || state_ == kMerge);
state_ = kMerge;
// value_pinner is not set from plain_table_reader.cc for example.
push_operand(value, value_pinner);
PERF_COUNTER_ADD(internal_merge_point_lookup_count, 1);
if (do_merge_ && merge_operator_ != nullptr &&
merge_operator_->ShouldMerge(
merge_context_->GetOperandsDirectionBackward())) {
state_ = kFound;
MergeWithNoBaseValue();
return false;
}
return true;
default:
assert(false);
break;
}
}
// state_ could be Corrupt, merge or notfound
return false;
}
void GetContext::PostprocessMerge(const Status& merge_status) {
if (!merge_status.ok()) {
if (merge_status.subcode() == Status::SubCode::kMergeOperatorFailed) {
state_ = kMergeOperatorFailed;
} else {
state_ = kCorrupt;
}
return;
}
if (LIKELY(pinnable_val_ != nullptr)) {
pinnable_val_->PinSelf();
}
}
void GetContext::MergeWithNoBaseValue() {
assert(do_merge_);
assert(pinnable_val_ || columns_);
assert(!pinnable_val_ || !columns_);
// `op_failure_scope` (an output parameter) is not provided (set to nullptr)
// since a failure must be propagated regardless of its value.
const Status s = MergeHelper::TimedFullMerge(
merge_operator_, user_key_, MergeHelper::kNoBaseValue,
merge_context_->GetOperands(), logger_, statistics_, clock_,
/* update_num_ops_stats */ true,
pinnable_val_ ? pinnable_val_->GetSelf() : nullptr, columns_,
/* op_failure_scope */ nullptr);
PostprocessMerge(s);
}
void GetContext::MergeWithPlainBaseValue(const Slice& value) {
assert(do_merge_);
assert(pinnable_val_ || columns_);
assert(!pinnable_val_ || !columns_);
// `op_failure_scope` (an output parameter) is not provided (set to nullptr)
// since a failure must be propagated regardless of its value.
const Status s = MergeHelper::TimedFullMerge(
merge_operator_, user_key_, MergeHelper::kPlainBaseValue, value,
merge_context_->GetOperands(), logger_, statistics_, clock_,
/* update_num_ops_stats */ true,
pinnable_val_ ? pinnable_val_->GetSelf() : nullptr, columns_,
/* op_failure_scope */ nullptr);
PostprocessMerge(s);
}
void GetContext::MergeWithWideColumnBaseValue(const Slice& entity) {
assert(do_merge_);
assert(pinnable_val_ || columns_);
assert(!pinnable_val_ || !columns_);
// `op_failure_scope` (an output parameter) is not provided (set to nullptr)
// since a failure must be propagated regardless of its value.
const Status s = MergeHelper::TimedFullMerge(
merge_operator_, user_key_, MergeHelper::kWideBaseValue, entity,
merge_context_->GetOperands(), logger_, statistics_, clock_,
/* update_num_ops_stats */ true,
pinnable_val_ ? pinnable_val_->GetSelf() : nullptr, columns_,
/* op_failure_scope */ nullptr);
PostprocessMerge(s);
}
bool GetContext::GetBlobValue(const Slice& user_key, const Slice& blob_index,
PinnableSlice* blob_value) {
constexpr FilePrefetchBuffer* prefetch_buffer = nullptr;
constexpr uint64_t* bytes_read = nullptr;
Status status = blob_fetcher_->FetchBlob(
user_key, blob_index, prefetch_buffer, blob_value, bytes_read);
if (!status.ok()) {
if (status.IsIncomplete()) {
// FIXME: this code is not covered by unit tests
MarkKeyMayExist();
return false;
}
state_ = kCorrupt;
return false;
}
*is_blob_index_ = false;
return true;
}
void GetContext::push_operand(const Slice& value, Cleanable* value_pinner) {
// TODO(yanqin) preserve timestamps information in merge_context
if (pinned_iters_mgr() && pinned_iters_mgr()->PinningEnabled() &&
value_pinner != nullptr) {
value_pinner->DelegateCleanupsTo(pinned_iters_mgr());
merge_context_->PushOperand(value, true /*value_pinned*/);
} else {
merge_context_->PushOperand(value, false);
}
}
void replayGetContextLog(const Slice& replay_log, const Slice& user_key,
GetContext* get_context, Cleanable* value_pinner,
SequenceNumber seq_no) {
Slice s = replay_log;
while (s.size()) {
auto type = static_cast<ValueType>(*s.data());
s.remove_prefix(1);
Slice value;
bool ret = GetLengthPrefixedSlice(&s, &value);
assert(ret);
(void)ret;
bool dont_care __attribute__((__unused__));
ParsedInternalKey ikey = ParsedInternalKey(user_key, seq_no, type);
get_context->SaveValue(ikey, value, &dont_care, value_pinner);
}
}
} // namespace ROCKSDB_NAMESPACE
Reference in a new issue View git blame Copy permalink