andreacavalli/rocksdb
0
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity
62d84e2a2b
rocksdb/db/db_block_cache_test.cc
Peter Dillinger bb87164db3 Fork and simplify LRUCache for developing enhancements (#9917) 
Summary:
To support a project to prototype and evaluate algorithmic
enhancments and alternatives to LRUCache, here I have separated out
LRUCache into internal-only "FastLRUCache" and cut it down to
essentials, so that details like secondary cache handling and
priorities do not interfere with prototyping. These can be
re-integrated later as needed, along with refactoring to minimize code
duplication (which would slow down prototyping for now).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9917

Test Plan:
unit tests updated to ensure basic functionality has (likely)
been preserved

Reviewed By: anand1976

Differential Revision: D35995554

Pulled By: pdillinger

fbshipit-source-id: d67b20b7ada3b5d3bfe56d897a73885894a1d9db
2022-05-03 12:32:02 -07:00

2124 lines
80 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).
//
// 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 <cstdlib>
#include <functional>
#include <memory>
#include <unordered_set>
#include "cache/cache_entry_roles.h"
#include "cache/cache_key.h"
#include "cache/fast_lru_cache.h"
#include "cache/lru_cache.h"
#include "db/column_family.h"
#include "db/db_impl/db_impl.h"
#include "db/db_test_util.h"
#include "env/unique_id_gen.h"
#include "port/stack_trace.h"
#include "rocksdb/persistent_cache.h"
#include "rocksdb/statistics.h"
#include "rocksdb/table.h"
#include "rocksdb/table_properties.h"
#include "table/block_based/block_based_table_reader.h"
#include "table/unique_id_impl.h"
#include "util/compression.h"
#include "util/defer.h"
#include "util/hash.h"
#include "util/math.h"
#include "util/random.h"
#include "utilities/fault_injection_fs.h"
namespace ROCKSDB_NAMESPACE {
class DBBlockCacheTest : public DBTestBase {
private:
size_t miss_count_ = 0;
size_t hit_count_ = 0;
size_t insert_count_ = 0;
size_t failure_count_ = 0;
size_t compression_dict_miss_count_ = 0;
size_t compression_dict_hit_count_ = 0;
size_t compression_dict_insert_count_ = 0;
size_t compressed_miss_count_ = 0;
size_t compressed_hit_count_ = 0;
size_t compressed_insert_count_ = 0;
size_t compressed_failure_count_ = 0;
public:
const size_t kNumBlocks = 10;
const size_t kValueSize = 100;
DBBlockCacheTest()
: DBTestBase("db_block_cache_test", /*env_do_fsync=*/true) {}
BlockBasedTableOptions GetTableOptions() {
BlockBasedTableOptions table_options;
// Set a small enough block size so that each key-value get its own block.
table_options.block_size = 1;
return table_options;
}
Options GetOptions(const BlockBasedTableOptions& table_options) {
Options options = CurrentOptions();
options.create_if_missing = true;
options.avoid_flush_during_recovery = false;
// options.compression = kNoCompression;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
return options;
}
void InitTable(const Options& /*options*/) {
std::string value(kValueSize, 'a');
for (size_t i = 0; i < kNumBlocks; i++) {
ASSERT_OK(Put(ToString(i), value.c_str()));
}
}
void RecordCacheCounters(const Options& options) {
miss_count_ = TestGetTickerCount(options, BLOCK_CACHE_MISS);
hit_count_ = TestGetTickerCount(options, BLOCK_CACHE_HIT);
insert_count_ = TestGetTickerCount(options, BLOCK_CACHE_ADD);
failure_count_ = TestGetTickerCount(options, BLOCK_CACHE_ADD_FAILURES);
compressed_miss_count_ =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_MISS);
compressed_hit_count_ =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_HIT);
compressed_insert_count_ =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_ADD);
compressed_failure_count_ =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_ADD_FAILURES);
}
void RecordCacheCountersForCompressionDict(const Options& options) {
compression_dict_miss_count_ =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSION_DICT_MISS);
compression_dict_hit_count_ =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSION_DICT_HIT);
compression_dict_insert_count_ =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSION_DICT_ADD);
}
void CheckCacheCounters(const Options& options, size_t expected_misses,
size_t expected_hits, size_t expected_inserts,
size_t expected_failures) {
size_t new_miss_count = TestGetTickerCount(options, BLOCK_CACHE_MISS);
size_t new_hit_count = TestGetTickerCount(options, BLOCK_CACHE_HIT);
size_t new_insert_count = TestGetTickerCount(options, BLOCK_CACHE_ADD);
size_t new_failure_count =
TestGetTickerCount(options, BLOCK_CACHE_ADD_FAILURES);
ASSERT_EQ(miss_count_ + expected_misses, new_miss_count);
ASSERT_EQ(hit_count_ + expected_hits, new_hit_count);
ASSERT_EQ(insert_count_ + expected_inserts, new_insert_count);
ASSERT_EQ(failure_count_ + expected_failures, new_failure_count);
miss_count_ = new_miss_count;
hit_count_ = new_hit_count;
insert_count_ = new_insert_count;
failure_count_ = new_failure_count;
}
void CheckCacheCountersForCompressionDict(
const Options& options, size_t expected_compression_dict_misses,
size_t expected_compression_dict_hits,
size_t expected_compression_dict_inserts) {
size_t new_compression_dict_miss_count =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSION_DICT_MISS);
size_t new_compression_dict_hit_count =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSION_DICT_HIT);
size_t new_compression_dict_insert_count =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSION_DICT_ADD);
ASSERT_EQ(compression_dict_miss_count_ + expected_compression_dict_misses,
new_compression_dict_miss_count);
ASSERT_EQ(compression_dict_hit_count_ + expected_compression_dict_hits,
new_compression_dict_hit_count);
ASSERT_EQ(
compression_dict_insert_count_ + expected_compression_dict_inserts,
new_compression_dict_insert_count);
compression_dict_miss_count_ = new_compression_dict_miss_count;
compression_dict_hit_count_ = new_compression_dict_hit_count;
compression_dict_insert_count_ = new_compression_dict_insert_count;
}
void CheckCompressedCacheCounters(const Options& options,
size_t expected_misses,
size_t expected_hits,
size_t expected_inserts,
size_t expected_failures) {
size_t new_miss_count =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_MISS);
size_t new_hit_count =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_HIT);
size_t new_insert_count =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_ADD);
size_t new_failure_count =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_ADD_FAILURES);
ASSERT_EQ(compressed_miss_count_ + expected_misses, new_miss_count);
ASSERT_EQ(compressed_hit_count_ + expected_hits, new_hit_count);
ASSERT_EQ(compressed_insert_count_ + expected_inserts, new_insert_count);
ASSERT_EQ(compressed_failure_count_ + expected_failures, new_failure_count);
compressed_miss_count_ = new_miss_count;
compressed_hit_count_ = new_hit_count;
compressed_insert_count_ = new_insert_count;
compressed_failure_count_ = new_failure_count;
}
#ifndef ROCKSDB_LITE
const std::array<size_t, kNumCacheEntryRoles> GetCacheEntryRoleCountsBg() {
// Verify in cache entry role stats
ColumnFamilyHandleImpl* cfh =
static_cast<ColumnFamilyHandleImpl*>(dbfull()->DefaultColumnFamily());
InternalStats* internal_stats_ptr = cfh->cfd()->internal_stats();
InternalStats::CacheEntryRoleStats stats;
internal_stats_ptr->TEST_GetCacheEntryRoleStats(&stats,
/*foreground=*/false);
return stats.entry_counts;
}
#endif // ROCKSDB_LITE
};
TEST_F(DBBlockCacheTest, IteratorBlockCacheUsage) {
ReadOptions read_options;
read_options.fill_cache = false;
auto table_options = GetTableOptions();
auto options = GetOptions(table_options);
InitTable(options);
LRUCacheOptions co;
co.capacity = 0;
co.num_shard_bits = 0;
co.strict_capacity_limit = false;
// Needed not to count entry stats collector
co.metadata_charge_policy = kDontChargeCacheMetadata;
std::shared_ptr<Cache> cache = NewLRUCache(co);
table_options.block_cache = cache;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
Reopen(options);
RecordCacheCounters(options);
std::vector<std::unique_ptr<Iterator>> iterators(kNumBlocks - 1);
Iterator* iter = nullptr;
ASSERT_EQ(0, cache->GetUsage());
iter = db_->NewIterator(read_options);
iter->Seek(ToString(0));
ASSERT_LT(0, cache->GetUsage());
delete iter;
iter = nullptr;
ASSERT_EQ(0, cache->GetUsage());
}
TEST_F(DBBlockCacheTest, TestWithoutCompressedBlockCache) {
ReadOptions read_options;
auto table_options = GetTableOptions();
auto options = GetOptions(table_options);
InitTable(options);
LRUCacheOptions co;
co.capacity = 0;
co.num_shard_bits = 0;
co.strict_capacity_limit = false;
// Needed not to count entry stats collector
co.metadata_charge_policy = kDontChargeCacheMetadata;
std::shared_ptr<Cache> cache = NewLRUCache(co);
table_options.block_cache = cache;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
Reopen(options);
RecordCacheCounters(options);
std::vector<std::unique_ptr<Iterator>> iterators(kNumBlocks - 1);
Iterator* iter = nullptr;
// Load blocks into cache.
for (size_t i = 0; i + 1 < kNumBlocks; i++) {
iter = db_->NewIterator(read_options);
iter->Seek(ToString(i));
ASSERT_OK(iter->status());
CheckCacheCounters(options, 1, 0, 1, 0);
iterators[i].reset(iter);
}
size_t usage = cache->GetUsage();
ASSERT_LT(0, usage);
cache->SetCapacity(usage);
ASSERT_EQ(usage, cache->GetPinnedUsage());
// Test with strict capacity limit.
cache->SetStrictCapacityLimit(true);
iter = db_->NewIterator(read_options);
iter->Seek(ToString(kNumBlocks - 1));
ASSERT_TRUE(iter->status().IsIncomplete());
CheckCacheCounters(options, 1, 0, 0, 1);
delete iter;
iter = nullptr;
// Release iterators and access cache again.
for (size_t i = 0; i + 1 < kNumBlocks; i++) {
iterators[i].reset();
CheckCacheCounters(options, 0, 0, 0, 0);
}
ASSERT_EQ(0, cache->GetPinnedUsage());
for (size_t i = 0; i + 1 < kNumBlocks; i++) {
iter = db_->NewIterator(read_options);
iter->Seek(ToString(i));
ASSERT_OK(iter->status());
CheckCacheCounters(options, 0, 1, 0, 0);
iterators[i].reset(iter);
}
}
#ifdef SNAPPY
TEST_F(DBBlockCacheTest, TestWithCompressedBlockCache) {
Options options = CurrentOptions();
options.create_if_missing = true;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
BlockBasedTableOptions table_options;
table_options.no_block_cache = true;
table_options.block_cache_compressed = nullptr;
table_options.block_size = 1;
table_options.filter_policy.reset(NewBloomFilterPolicy(20));
table_options.cache_index_and_filter_blocks = false;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
options.compression = CompressionType::kSnappyCompression;
DestroyAndReopen(options);
std::string value(kValueSize, 'a');
for (size_t i = 0; i < kNumBlocks; i++) {
ASSERT_OK(Put(ToString(i), value));
ASSERT_OK(Flush());
}
ReadOptions read_options;
std::shared_ptr<Cache> compressed_cache = NewLRUCache(1 << 25, 0, false);
LRUCacheOptions co;
co.capacity = 0;
co.num_shard_bits = 0;
co.strict_capacity_limit = false;
// Needed not to count entry stats collector
co.metadata_charge_policy = kDontChargeCacheMetadata;
std::shared_ptr<Cache> cache = NewLRUCache(co);
table_options.block_cache = cache;
table_options.no_block_cache = false;
table_options.block_cache_compressed = compressed_cache;
table_options.max_auto_readahead_size = 0;
table_options.cache_index_and_filter_blocks = false;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
Reopen(options);
RecordCacheCounters(options);
// Load blocks into cache.
for (size_t i = 0; i < kNumBlocks - 1; i++) {
ASSERT_EQ(value, Get(ToString(i)));
CheckCacheCounters(options, 1, 0, 1, 0);
CheckCompressedCacheCounters(options, 1, 0, 1, 0);
}
size_t usage = cache->GetUsage();
ASSERT_EQ(0, usage);
ASSERT_EQ(usage, cache->GetPinnedUsage());
size_t compressed_usage = compressed_cache->GetUsage();
ASSERT_LT(0, compressed_usage);
// Compressed block cache cannot be pinned.
ASSERT_EQ(0, compressed_cache->GetPinnedUsage());
// Set strict capacity limit flag. Now block will only load into compressed
// block cache.
cache->SetCapacity(usage);
cache->SetStrictCapacityLimit(true);
ASSERT_EQ(usage, cache->GetPinnedUsage());
// Load last key block.
ASSERT_EQ("Result incomplete: Insert failed due to LRU cache being full.",
Get(ToString(kNumBlocks - 1)));
// Failure will also record the miss counter.
CheckCacheCounters(options, 1, 0, 0, 1);
CheckCompressedCacheCounters(options, 1, 0, 1, 0);
// Clear strict capacity limit flag. This time we shall hit compressed block
// cache and load into block cache.
cache->SetStrictCapacityLimit(false);
// Load last key block.
ASSERT_EQ(value, Get(ToString(kNumBlocks - 1)));
CheckCacheCounters(options, 1, 0, 1, 0);
CheckCompressedCacheCounters(options, 0, 1, 0, 0);
}
namespace {
class PersistentCacheFromCache : public PersistentCache {
public:
PersistentCacheFromCache(std::shared_ptr<Cache> cache, bool read_only)
: cache_(cache), read_only_(read_only) {}
Status Insert(const Slice& key, const char* data,
const size_t size) override {
if (read_only_) {
return Status::NotSupported();
}
std::unique_ptr<char[]> copy{new char[size]};
std::copy_n(data, size, copy.get());
Status s = cache_->Insert(
key, copy.get(), size,
GetCacheEntryDeleterForRole<char[], CacheEntryRole::kMisc>());
if (s.ok()) {
copy.release();
}
return s;
}
Status Lookup(const Slice& key, std::unique_ptr<char[]>* data,
size_t* size) override {
auto handle = cache_->Lookup(key);
if (handle) {
char* ptr = static_cast<char*>(cache_->Value(handle));
*size = cache_->GetCharge(handle);
data->reset(new char[*size]);
std::copy_n(ptr, *size, data->get());
cache_->Release(handle);
return Status::OK();
} else {
return Status::NotFound();
}
}
bool IsCompressed() override { return false; }
StatsType Stats() override { return StatsType(); }
std::string GetPrintableOptions() const override { return ""; }
uint64_t NewId() override { return cache_->NewId(); }
private:
std::shared_ptr<Cache> cache_;
bool read_only_;
};
class ReadOnlyCacheWrapper : public CacheWrapper {
using CacheWrapper::CacheWrapper;
using Cache::Insert;
Status Insert(const Slice& /*key*/, void* /*value*/, size_t /*charge*/,
void (*)(const Slice& key, void* value) /*deleter*/,
Handle** /*handle*/, Priority /*priority*/) override {
return Status::NotSupported();
}
};
} // namespace
TEST_F(DBBlockCacheTest, TestWithSameCompressed) {
auto table_options = GetTableOptions();
auto options = GetOptions(table_options);
InitTable(options);
std::shared_ptr<Cache> rw_cache{NewLRUCache(1000000)};
std::shared_ptr<PersistentCacheFromCache> rw_pcache{
new PersistentCacheFromCache(rw_cache, /*read_only*/ false)};
// Exercise some obscure behavior with read-only wrappers
std::shared_ptr<Cache> ro_cache{new ReadOnlyCacheWrapper(rw_cache)};
std::shared_ptr<PersistentCacheFromCache> ro_pcache{
new PersistentCacheFromCache(rw_cache, /*read_only*/ true)};
// Simple same pointer
table_options.block_cache = rw_cache;
table_options.block_cache_compressed = rw_cache;
table_options.persistent_cache.reset();
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
ASSERT_EQ(TryReopen(options).ToString(),
"Invalid argument: block_cache same as block_cache_compressed not "
"currently supported, and would be bad for performance anyway");
// Other cases
table_options.block_cache = ro_cache;
table_options.block_cache_compressed = rw_cache;
table_options.persistent_cache.reset();
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
ASSERT_EQ(TryReopen(options).ToString(),
"Invalid argument: block_cache and block_cache_compressed share "
"the same key space, which is not supported");
table_options.block_cache = rw_cache;
table_options.block_cache_compressed = ro_cache;
table_options.persistent_cache.reset();
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
ASSERT_EQ(TryReopen(options).ToString(),
"Invalid argument: block_cache_compressed and block_cache share "
"the same key space, which is not supported");
table_options.block_cache = ro_cache;
table_options.block_cache_compressed.reset();
table_options.persistent_cache = rw_pcache;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
ASSERT_EQ(TryReopen(options).ToString(),
"Invalid argument: block_cache and persistent_cache share the same "
"key space, which is not supported");
table_options.block_cache = rw_cache;
table_options.block_cache_compressed.reset();
table_options.persistent_cache = ro_pcache;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
ASSERT_EQ(TryReopen(options).ToString(),
"Invalid argument: persistent_cache and block_cache share the same "
"key space, which is not supported");
table_options.block_cache.reset();
table_options.no_block_cache = true;
table_options.block_cache_compressed = ro_cache;
table_options.persistent_cache = rw_pcache;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
ASSERT_EQ(TryReopen(options).ToString(),
"Invalid argument: block_cache_compressed and persistent_cache "
"share the same key space, which is not supported");
table_options.block_cache.reset();
table_options.no_block_cache = true;
table_options.block_cache_compressed = rw_cache;
table_options.persistent_cache = ro_pcache;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
ASSERT_EQ(TryReopen(options).ToString(),
"Invalid argument: persistent_cache and block_cache_compressed "
"share the same key space, which is not supported");
}
#endif // SNAPPY
#ifndef ROCKSDB_LITE
// Make sure that when options.block_cache is set, after a new table is
// created its index/filter blocks are added to block cache.
TEST_F(DBBlockCacheTest, IndexAndFilterBlocksOfNewTableAddedToCache) {
Options options = CurrentOptions();
options.create_if_missing = true;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
BlockBasedTableOptions table_options;
table_options.cache_index_and_filter_blocks = true;
table_options.filter_policy.reset(NewBloomFilterPolicy(20));
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
CreateAndReopenWithCF({"pikachu"}, options);
ASSERT_OK(Put(1, "key", "val"));
// Create a new table.
ASSERT_OK(Flush(1));
// index/filter blocks added to block cache right after table creation.
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_MISS));
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS));
ASSERT_EQ(2, /* only index/filter were added */
TestGetTickerCount(options, BLOCK_CACHE_ADD));
ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_DATA_MISS));
uint64_t int_num;
ASSERT_TRUE(
dbfull()->GetIntProperty("rocksdb.estimate-table-readers-mem", &int_num));
ASSERT_EQ(int_num, 0U);
// Make sure filter block is in cache.
std::string value;
ReadOptions ropt;
db_->KeyMayExist(ReadOptions(), handles_[1], "key", &value);
// Miss count should remain the same.
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS));
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_HIT));
db_->KeyMayExist(ReadOptions(), handles_[1], "key", &value);
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS));
ASSERT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_FILTER_HIT));
// Make sure index block is in cache.
auto index_block_hit = TestGetTickerCount(options, BLOCK_CACHE_INDEX_HIT);
value = Get(1, "key");
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_MISS));
ASSERT_EQ(index_block_hit + 1,
TestGetTickerCount(options, BLOCK_CACHE_INDEX_HIT));
value = Get(1, "key");
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_MISS));
ASSERT_EQ(index_block_hit + 2,
TestGetTickerCount(options, BLOCK_CACHE_INDEX_HIT));
}
// With fill_cache = false, fills up the cache, then iterates over the entire
// db, verify dummy entries inserted in `BlockBasedTable::NewDataBlockIterator`
// does not cause heap-use-after-free errors in COMPILE_WITH_ASAN=1 runs
TEST_F(DBBlockCacheTest, FillCacheAndIterateDB) {
ReadOptions read_options;
read_options.fill_cache = false;
auto table_options = GetTableOptions();
auto options = GetOptions(table_options);
InitTable(options);
std::shared_ptr<Cache> cache = NewLRUCache(10, 0, true);
table_options.block_cache = cache;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
Reopen(options);
ASSERT_OK(Put("key1", "val1"));
ASSERT_OK(Put("key2", "val2"));
ASSERT_OK(Flush());
ASSERT_OK(Put("key3", "val3"));
ASSERT_OK(Put("key4", "val4"));
ASSERT_OK(Flush());
ASSERT_OK(Put("key5", "val5"));
ASSERT_OK(Put("key6", "val6"));
ASSERT_OK(Flush());
Iterator* iter = nullptr;
iter = db_->NewIterator(read_options);
iter->Seek(ToString(0));
while (iter->Valid()) {
iter->Next();
}
delete iter;
iter = nullptr;
}
TEST_F(DBBlockCacheTest, IndexAndFilterBlocksStats) {
Options options = CurrentOptions();
options.create_if_missing = true;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
BlockBasedTableOptions table_options;
table_options.cache_index_and_filter_blocks = true;
LRUCacheOptions co;
// 500 bytes are enough to hold the first two blocks
co.capacity = 500;
co.num_shard_bits = 0;
co.strict_capacity_limit = false;
co.metadata_charge_policy = kDontChargeCacheMetadata;
std::shared_ptr<Cache> cache = NewLRUCache(co);
table_options.block_cache = cache;
table_options.filter_policy.reset(NewBloomFilterPolicy(20, true));
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
CreateAndReopenWithCF({"pikachu"}, options);
ASSERT_OK(Put(1, "longer_key", "val"));
// Create a new table
ASSERT_OK(Flush(1));
size_t index_bytes_insert =
TestGetTickerCount(options, BLOCK_CACHE_INDEX_BYTES_INSERT);
size_t filter_bytes_insert =
TestGetTickerCount(options, BLOCK_CACHE_FILTER_BYTES_INSERT);
ASSERT_GT(index_bytes_insert, 0);
ASSERT_GT(filter_bytes_insert, 0);
ASSERT_EQ(cache->GetUsage(), index_bytes_insert + filter_bytes_insert);
// set the cache capacity to the current usage
cache->SetCapacity(index_bytes_insert + filter_bytes_insert);
// The index and filter eviction statistics were broken by the refactoring
// that moved the readers out of the block cache. Disabling these until we can
// bring the stats back.
// ASSERT_EQ(TestGetTickerCount(options, BLOCK_CACHE_INDEX_BYTES_EVICT), 0);
// ASSERT_EQ(TestGetTickerCount(options, BLOCK_CACHE_FILTER_BYTES_EVICT), 0);
// Note that the second key needs to be no longer than the first one.
// Otherwise the second index block may not fit in cache.
ASSERT_OK(Put(1, "key", "val"));
// Create a new table
ASSERT_OK(Flush(1));
// cache evicted old index and block entries
ASSERT_GT(TestGetTickerCount(options, BLOCK_CACHE_INDEX_BYTES_INSERT),
index_bytes_insert);
ASSERT_GT(TestGetTickerCount(options, BLOCK_CACHE_FILTER_BYTES_INSERT),
filter_bytes_insert);
// The index and filter eviction statistics were broken by the refactoring
// that moved the readers out of the block cache. Disabling these until we can
// bring the stats back.
// ASSERT_EQ(TestGetTickerCount(options, BLOCK_CACHE_INDEX_BYTES_EVICT),
// index_bytes_insert);
// ASSERT_EQ(TestGetTickerCount(options, BLOCK_CACHE_FILTER_BYTES_EVICT),
// filter_bytes_insert);
}
#if (defined OS_LINUX || defined OS_WIN)
TEST_F(DBBlockCacheTest, WarmCacheWithDataBlocksDuringFlush) {
Options options = CurrentOptions();
options.create_if_missing = true;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
BlockBasedTableOptions table_options;
table_options.block_cache = NewLRUCache(1 << 25, 0, false);
table_options.cache_index_and_filter_blocks = false;
table_options.prepopulate_block_cache =
BlockBasedTableOptions::PrepopulateBlockCache::kFlushOnly;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
DestroyAndReopen(options);
std::string value(kValueSize, 'a');
for (size_t i = 1; i <= kNumBlocks; i++) {
ASSERT_OK(Put(ToString(i), value));
ASSERT_OK(Flush());
ASSERT_EQ(i, options.statistics->getTickerCount(BLOCK_CACHE_DATA_ADD));
ASSERT_EQ(value, Get(ToString(i)));
ASSERT_EQ(0, options.statistics->getTickerCount(BLOCK_CACHE_DATA_MISS));
ASSERT_EQ(i, options.statistics->getTickerCount(BLOCK_CACHE_DATA_HIT));
}
// Verify compaction not counted
ASSERT_OK(db_->CompactRange(CompactRangeOptions(), /*begin=*/nullptr,
/*end=*/nullptr));
EXPECT_EQ(kNumBlocks,
options.statistics->getTickerCount(BLOCK_CACHE_DATA_ADD));
}
// This test cache data, index and filter blocks during flush.
class DBBlockCacheTest1 : public DBTestBase,
public ::testing::WithParamInterface<uint32_t> {
public:
const size_t kNumBlocks = 10;
const size_t kValueSize = 100;
DBBlockCacheTest1() : DBTestBase("db_block_cache_test1", true) {}
};
INSTANTIATE_TEST_CASE_P(DBBlockCacheTest1, DBBlockCacheTest1,
::testing::Values(1, 2, 3));
TEST_P(DBBlockCacheTest1, WarmCacheWithBlocksDuringFlush) {
Options options = CurrentOptions();
options.create_if_missing = true;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
BlockBasedTableOptions table_options;
table_options.block_cache = NewLRUCache(1 << 25, 0, false);
uint32_t filter_type = GetParam();
switch (filter_type) {
case 1: // partition_filter
table_options.partition_filters = true;
table_options.index_type =
BlockBasedTableOptions::IndexType::kTwoLevelIndexSearch;
table_options.filter_policy.reset(NewBloomFilterPolicy(10, false));
break;
case 2: // block-based filter
table_options.filter_policy.reset(NewBloomFilterPolicy(10, true));
break;
case 3: // full filter
table_options.filter_policy.reset(NewBloomFilterPolicy(10, false));
break;
default:
assert(false);
}
table_options.cache_index_and_filter_blocks = true;
table_options.prepopulate_block_cache =
BlockBasedTableOptions::PrepopulateBlockCache::kFlushOnly;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
DestroyAndReopen(options);
std::string value(kValueSize, 'a');
for (size_t i = 1; i <= kNumBlocks; i++) {
ASSERT_OK(Put(ToString(i), value));
ASSERT_OK(Flush());
ASSERT_EQ(i, options.statistics->getTickerCount(BLOCK_CACHE_DATA_ADD));
if (filter_type == 1) {
ASSERT_EQ(2 * i,
options.statistics->getTickerCount(BLOCK_CACHE_INDEX_ADD));
ASSERT_EQ(2 * i,
options.statistics->getTickerCount(BLOCK_CACHE_FILTER_ADD));
} else {
ASSERT_EQ(i, options.statistics->getTickerCount(BLOCK_CACHE_INDEX_ADD));
ASSERT_EQ(i, options.statistics->getTickerCount(BLOCK_CACHE_FILTER_ADD));
}
ASSERT_EQ(value, Get(ToString(i)));
ASSERT_EQ(0, options.statistics->getTickerCount(BLOCK_CACHE_DATA_MISS));
ASSERT_EQ(i, options.statistics->getTickerCount(BLOCK_CACHE_DATA_HIT));
ASSERT_EQ(0, options.statistics->getTickerCount(BLOCK_CACHE_INDEX_MISS));
ASSERT_EQ(i * 3, options.statistics->getTickerCount(BLOCK_CACHE_INDEX_HIT));
if (filter_type == 1) {
ASSERT_EQ(i * 3,
options.statistics->getTickerCount(BLOCK_CACHE_FILTER_HIT));
} else {
ASSERT_EQ(i * 2,
options.statistics->getTickerCount(BLOCK_CACHE_FILTER_HIT));
}
ASSERT_EQ(0, options.statistics->getTickerCount(BLOCK_CACHE_FILTER_MISS));
}
// Verify compaction not counted
ASSERT_OK(db_->CompactRange(CompactRangeOptions(), /*begin=*/nullptr,
/*end=*/nullptr));
EXPECT_EQ(kNumBlocks,
options.statistics->getTickerCount(BLOCK_CACHE_DATA_ADD));
// Index and filter blocks are automatically warmed when the new table file
// is automatically opened at the end of compaction. This is not easily
// disabled so results in the new index and filter blocks being warmed.
if (filter_type == 1) {
EXPECT_EQ(2 * (1 + kNumBlocks),
options.statistics->getTickerCount(BLOCK_CACHE_INDEX_ADD));
EXPECT_EQ(2 * (1 + kNumBlocks),
options.statistics->getTickerCount(BLOCK_CACHE_FILTER_ADD));
} else {
EXPECT_EQ(1 + kNumBlocks,
options.statistics->getTickerCount(BLOCK_CACHE_INDEX_ADD));
EXPECT_EQ(1 + kNumBlocks,
options.statistics->getTickerCount(BLOCK_CACHE_FILTER_ADD));
}
}
TEST_F(DBBlockCacheTest, DynamicallyWarmCacheDuringFlush) {
Options options = CurrentOptions();
options.create_if_missing = true;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
BlockBasedTableOptions table_options;
table_options.block_cache = NewLRUCache(1 << 25, 0, false);
table_options.cache_index_and_filter_blocks = false;
table_options.prepopulate_block_cache =
BlockBasedTableOptions::PrepopulateBlockCache::kFlushOnly;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
DestroyAndReopen(options);
std::string value(kValueSize, 'a');
for (size_t i = 1; i <= 5; i++) {
ASSERT_OK(Put(ToString(i), value));
ASSERT_OK(Flush());
ASSERT_EQ(1,
options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_ADD));
ASSERT_EQ(value, Get(ToString(i)));
ASSERT_EQ(0,
options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_ADD));
ASSERT_EQ(
0, options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_MISS));
ASSERT_EQ(1,
options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_HIT));
}
ASSERT_OK(dbfull()->SetOptions(
{{"block_based_table_factory", "{prepopulate_block_cache=kDisable;}"}}));
for (size_t i = 6; i <= kNumBlocks; i++) {
ASSERT_OK(Put(ToString(i), value));
ASSERT_OK(Flush());
ASSERT_EQ(0,
options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_ADD));
ASSERT_EQ(value, Get(ToString(i)));
ASSERT_EQ(1,
options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_ADD));
ASSERT_EQ(
1, options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_MISS));
ASSERT_EQ(0,
options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_HIT));
}
}
#endif
namespace {
// A mock cache wraps LRUCache, and record how many entries have been
// inserted for each priority.
class MockCache : public LRUCache {
public:
static uint32_t high_pri_insert_count;
static uint32_t low_pri_insert_count;
MockCache()
: LRUCache((size_t)1 << 25 /*capacity*/, 0 /*num_shard_bits*/,
false /*strict_capacity_limit*/, 0.0 /*high_pri_pool_ratio*/) {
}
using ShardedCache::Insert;
Status Insert(const Slice& key, void* value,
const Cache::CacheItemHelper* helper_cb, size_t charge,
Handle** handle, Priority priority) override {
DeleterFn delete_cb = helper_cb->del_cb;
if (priority == Priority::LOW) {
low_pri_insert_count++;
} else {
high_pri_insert_count++;
}
return LRUCache::Insert(key, value, charge, delete_cb, handle, priority);
}
};
uint32_t MockCache::high_pri_insert_count = 0;
uint32_t MockCache::low_pri_insert_count = 0;
} // anonymous namespace
TEST_F(DBBlockCacheTest, IndexAndFilterBlocksCachePriority) {
for (auto priority : {Cache::Priority::LOW, Cache::Priority::HIGH}) {
Options options = CurrentOptions();
options.create_if_missing = true;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
BlockBasedTableOptions table_options;
table_options.cache_index_and_filter_blocks = true;
table_options.block_cache.reset(new MockCache());
table_options.filter_policy.reset(NewBloomFilterPolicy(20));
table_options.cache_index_and_filter_blocks_with_high_priority =
priority == Cache::Priority::HIGH ? true : false;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
DestroyAndReopen(options);
MockCache::high_pri_insert_count = 0;
MockCache::low_pri_insert_count = 0;
// Create a new table.
ASSERT_OK(Put("foo", "value"));
ASSERT_OK(Put("bar", "value"));
ASSERT_OK(Flush());
ASSERT_EQ(1, NumTableFilesAtLevel(0));
// index/filter blocks added to block cache right after table creation.
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_MISS));
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS));
ASSERT_EQ(2, /* only index/filter were added */
TestGetTickerCount(options, BLOCK_CACHE_ADD));
ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_DATA_MISS));
if (priority == Cache::Priority::LOW) {
ASSERT_EQ(0u, MockCache::high_pri_insert_count);
ASSERT_EQ(2u, MockCache::low_pri_insert_count);
} else {
ASSERT_EQ(2u, MockCache::high_pri_insert_count);
ASSERT_EQ(0u, MockCache::low_pri_insert_count);
}
// Access data block.
ASSERT_EQ("value", Get("foo"));
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_MISS));
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS));
ASSERT_EQ(3, /*adding data block*/
TestGetTickerCount(options, BLOCK_CACHE_ADD));
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_DATA_MISS));
// Data block should be inserted with low priority.
if (priority == Cache::Priority::LOW) {
ASSERT_EQ(0u, MockCache::high_pri_insert_count);
ASSERT_EQ(3u, MockCache::low_pri_insert_count);
} else {
ASSERT_EQ(2u, MockCache::high_pri_insert_count);
ASSERT_EQ(1u, MockCache::low_pri_insert_count);
}
}
}
namespace {
// An LRUCache wrapper that can falsely report "not found" on Lookup.
// This allows us to manipulate BlockBasedTableReader into thinking
// another thread inserted the data in between Lookup and Insert,
// while mostly preserving the LRUCache interface/behavior.
class LookupLiarCache : public CacheWrapper {
int nth_lookup_not_found_ = 0;
public:
explicit LookupLiarCache(std::shared_ptr<Cache> target)
: CacheWrapper(std::move(target)) {}
using Cache::Lookup;
Handle* Lookup(const Slice& key, Statistics* stats) override {
if (nth_lookup_not_found_ == 1) {
nth_lookup_not_found_ = 0;
return nullptr;
}
if (nth_lookup_not_found_ > 1) {
--nth_lookup_not_found_;
}
return CacheWrapper::Lookup(key, stats);
}
// 1 == next lookup, 2 == after next, etc.
void SetNthLookupNotFound(int n) { nth_lookup_not_found_ = n; }
};
} // anonymous namespace
TEST_F(DBBlockCacheTest, AddRedundantStats) {
const size_t capacity = size_t{1} << 25;
const int num_shard_bits = 0; // 1 shard
int iterations_tested = 0;
for (std::shared_ptr<Cache> base_cache :
{NewLRUCache(capacity, num_shard_bits),
NewClockCache(capacity, num_shard_bits),
NewFastLRUCache(capacity, num_shard_bits)}) {
if (!base_cache) {
// Skip clock cache when not supported
continue;
}
++iterations_tested;
Options options = CurrentOptions();
options.create_if_missing = true;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
std::shared_ptr<LookupLiarCache> cache =
std::make_shared<LookupLiarCache>(base_cache);
BlockBasedTableOptions table_options;
table_options.cache_index_and_filter_blocks = true;
table_options.block_cache = cache;
table_options.filter_policy.reset(NewBloomFilterPolicy(50));
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
DestroyAndReopen(options);
// Create a new table.
ASSERT_OK(Put("foo", "value"));
ASSERT_OK(Put("bar", "value"));
ASSERT_OK(Flush());
ASSERT_EQ(1, NumTableFilesAtLevel(0));
// Normal access filter+index+data.
ASSERT_EQ("value", Get("foo"));
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD));
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD));
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD));
// --------
ASSERT_EQ(3, TestGetTickerCount(options, BLOCK_CACHE_ADD));
ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD_REDUNDANT));
ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD_REDUNDANT));
ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD_REDUNDANT));
// --------
ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_ADD_REDUNDANT));
// Againt access filter+index+data, but force redundant load+insert on index
cache->SetNthLookupNotFound(2);
ASSERT_EQ("value", Get("bar"));
ASSERT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD));
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD));
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD));
// --------
ASSERT_EQ(4, TestGetTickerCount(options, BLOCK_CACHE_ADD));
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD_REDUNDANT));
ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD_REDUNDANT));
ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD_REDUNDANT));
// --------
ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_ADD_REDUNDANT));
// Access just filter (with high probability), and force redundant
// load+insert
cache->SetNthLookupNotFound(1);
ASSERT_EQ("NOT_FOUND", Get("this key was not added"));
EXPECT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD));
EXPECT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD));
EXPECT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD));
// --------
EXPECT_EQ(5, TestGetTickerCount(options, BLOCK_CACHE_ADD));
EXPECT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD_REDUNDANT));
EXPECT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD_REDUNDANT));
EXPECT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD_REDUNDANT));
// --------
EXPECT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_ADD_REDUNDANT));
// Access just data, forcing redundant load+insert
ReadOptions read_options;
std::unique_ptr<Iterator> iter{db_->NewIterator(read_options)};
cache->SetNthLookupNotFound(1);
iter->SeekToFirst();
ASSERT_TRUE(iter->Valid());
ASSERT_EQ(iter->key(), "bar");
EXPECT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD));
EXPECT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD));
EXPECT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD));
// --------
EXPECT_EQ(6, TestGetTickerCount(options, BLOCK_CACHE_ADD));
EXPECT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD_REDUNDANT));
EXPECT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD_REDUNDANT));
EXPECT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD_REDUNDANT));
// --------
EXPECT_EQ(3, TestGetTickerCount(options, BLOCK_CACHE_ADD_REDUNDANT));
}
EXPECT_GE(iterations_tested, 1);
}
TEST_F(DBBlockCacheTest, ParanoidFileChecks) {
Options options = CurrentOptions();
options.create_if_missing = true;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
options.level0_file_num_compaction_trigger = 2;
options.paranoid_file_checks = true;
BlockBasedTableOptions table_options;
table_options.cache_index_and_filter_blocks = false;
table_options.filter_policy.reset(NewBloomFilterPolicy(20));
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
CreateAndReopenWithCF({"pikachu"}, options);
ASSERT_OK(Put(1, "1_key", "val"));
ASSERT_OK(Put(1, "9_key", "val"));
// Create a new table.
ASSERT_OK(Flush(1));
ASSERT_EQ(1, /* read and cache data block */
TestGetTickerCount(options, BLOCK_CACHE_ADD));
ASSERT_OK(Put(1, "1_key2", "val2"));
ASSERT_OK(Put(1, "9_key2", "val2"));
// Create a new SST file. This will further trigger a compaction
// and generate another file.
ASSERT_OK(Flush(1));
ASSERT_OK(dbfull()->TEST_WaitForCompact());
ASSERT_EQ(3, /* Totally 3 files created up to now */
TestGetTickerCount(options, BLOCK_CACHE_ADD));
// After disabling options.paranoid_file_checks. NO further block
// is added after generating a new file.
ASSERT_OK(
dbfull()->SetOptions(handles_[1], {{"paranoid_file_checks", "false"}}));
ASSERT_OK(Put(1, "1_key3", "val3"));
ASSERT_OK(Put(1, "9_key3", "val3"));
ASSERT_OK(Flush(1));
ASSERT_OK(Put(1, "1_key4", "val4"));
ASSERT_OK(Put(1, "9_key4", "val4"));
ASSERT_OK(Flush(1));
ASSERT_OK(dbfull()->TEST_WaitForCompact());
ASSERT_EQ(3, /* Totally 3 files created up to now */
TestGetTickerCount(options, BLOCK_CACHE_ADD));
}
TEST_F(DBBlockCacheTest, CompressedCache) {
if (!Snappy_Supported()) {
return;
}
int num_iter = 80;
// Run this test three iterations.
// Iteration 1: only a uncompressed block cache
// Iteration 2: only a compressed block cache
// Iteration 3: both block cache and compressed cache
// Iteration 4: both block cache and compressed cache, but DB is not
// compressed
for (int iter = 0; iter < 4; iter++) {
Options options = CurrentOptions();
options.write_buffer_size = 64 * 1024; // small write buffer
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
BlockBasedTableOptions table_options;
switch (iter) {
case 0:
// only uncompressed block cache
table_options.block_cache = NewLRUCache(8 * 1024);
table_options.block_cache_compressed = nullptr;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
break;
case 1:
// no block cache, only compressed cache
table_options.no_block_cache = true;
table_options.block_cache = nullptr;
table_options.block_cache_compressed = NewLRUCache(8 * 1024);
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
break;
case 2:
// both compressed and uncompressed block cache
table_options.block_cache = NewLRUCache(1024);
table_options.block_cache_compressed = NewLRUCache(8 * 1024);
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
break;
case 3:
// both block cache and compressed cache, but DB is not compressed
// also, make block cache sizes bigger, to trigger block cache hits
table_options.block_cache = NewLRUCache(1024 * 1024);
table_options.block_cache_compressed = NewLRUCache(8 * 1024 * 1024);
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
options.compression = kNoCompression;
break;
default:
FAIL();
}
CreateAndReopenWithCF({"pikachu"}, options);
// default column family doesn't have block cache
Options no_block_cache_opts;
no_block_cache_opts.statistics = options.statistics;
no_block_cache_opts = CurrentOptions(no_block_cache_opts);
BlockBasedTableOptions table_options_no_bc;
table_options_no_bc.no_block_cache = true;
no_block_cache_opts.table_factory.reset(
NewBlockBasedTableFactory(table_options_no_bc));
ReopenWithColumnFamilies(
{"default", "pikachu"},
std::vector<Options>({no_block_cache_opts, options}));
Random rnd(301);
// Write 8MB (80 values, each 100K)
ASSERT_EQ(NumTableFilesAtLevel(0, 1), 0);
std::vector<std::string> values;
std::string str;
for (int i = 0; i < num_iter; i++) {
if (i % 4 == 0) { // high compression ratio
str = rnd.RandomString(1000);
}
values.push_back(str);
ASSERT_OK(Put(1, Key(i), values[i]));
}
// flush all data from memtable so that reads are from block cache
ASSERT_OK(Flush(1));
for (int i = 0; i < num_iter; i++) {
ASSERT_EQ(Get(1, Key(i)), values[i]);
}
// check that we triggered the appropriate code paths in the cache
switch (iter) {
case 0:
// only uncompressed block cache
ASSERT_GT(TestGetTickerCount(options, BLOCK_CACHE_MISS), 0);
ASSERT_EQ(TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_MISS), 0);
break;
case 1:
// no block cache, only compressed cache
ASSERT_EQ(TestGetTickerCount(options, BLOCK_CACHE_MISS), 0);
ASSERT_GT(TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_MISS), 0);
break;
case 2:
// both compressed and uncompressed block cache
ASSERT_GT(TestGetTickerCount(options, BLOCK_CACHE_MISS), 0);
ASSERT_GT(TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_MISS), 0);
break;
case 3:
// both compressed and uncompressed block cache
ASSERT_GT(TestGetTickerCount(options, BLOCK_CACHE_MISS), 0);
ASSERT_GT(TestGetTickerCount(options, BLOCK_CACHE_HIT), 0);
ASSERT_GT(TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_MISS), 0);
// compressed doesn't have any hits since blocks are not compressed on
// storage
ASSERT_EQ(TestGetTickerCount(options, BLOCK_CACHE_COMPRESSED_HIT), 0);
break;
default:
FAIL();
}
options.create_if_missing = true;
DestroyAndReopen(options);
}
}
TEST_F(DBBlockCacheTest, CacheCompressionDict) {
const int kNumFiles = 4;
const int kNumEntriesPerFile = 128;
const int kNumBytesPerEntry = 1024;
// Try all the available libraries that support dictionary compression
std::vector<CompressionType> compression_types;
if (Zlib_Supported()) {
compression_types.push_back(kZlibCompression);
}
if (LZ4_Supported()) {
compression_types.push_back(kLZ4Compression);
compression_types.push_back(kLZ4HCCompression);
}
if (ZSTD_Supported()) {
compression_types.push_back(kZSTD);
} else if (ZSTDNotFinal_Supported()) {
compression_types.push_back(kZSTDNotFinalCompression);
}
Random rnd(301);
for (auto compression_type : compression_types) {
Options options = CurrentOptions();
options.bottommost_compression = compression_type;
options.bottommost_compression_opts.max_dict_bytes = 4096;
options.bottommost_compression_opts.enabled = true;
options.create_if_missing = true;
options.num_levels = 2;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
options.target_file_size_base = kNumEntriesPerFile * kNumBytesPerEntry;
BlockBasedTableOptions table_options;
table_options.cache_index_and_filter_blocks = true;
table_options.block_cache.reset(new MockCache());
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
DestroyAndReopen(options);
RecordCacheCountersForCompressionDict(options);
for (int i = 0; i < kNumFiles; ++i) {
ASSERT_EQ(i, NumTableFilesAtLevel(0, 0));
for (int j = 0; j < kNumEntriesPerFile; ++j) {
std::string value = rnd.RandomString(kNumBytesPerEntry);
ASSERT_OK(Put(Key(j * kNumFiles + i), value.c_str()));
}
ASSERT_OK(Flush());
}
ASSERT_OK(dbfull()->TEST_WaitForCompact());
ASSERT_EQ(0, NumTableFilesAtLevel(0));
ASSERT_EQ(kNumFiles, NumTableFilesAtLevel(1));
// Compression dictionary blocks are preloaded.
CheckCacheCountersForCompressionDict(
options, kNumFiles /* expected_compression_dict_misses */,
0 /* expected_compression_dict_hits */,
kNumFiles /* expected_compression_dict_inserts */);
// Seek to a key in a file. It should cause the SST's dictionary meta-block
// to be read.
RecordCacheCounters(options);
RecordCacheCountersForCompressionDict(options);
ReadOptions read_options;
ASSERT_NE("NOT_FOUND", Get(Key(kNumFiles * kNumEntriesPerFile - 1)));
// Two block hits: index and dictionary since they are prefetched
// One block missed/added: data block
CheckCacheCounters(options, 1 /* expected_misses */, 2 /* expected_hits */,
1 /* expected_inserts */, 0 /* expected_failures */);
CheckCacheCountersForCompressionDict(
options, 0 /* expected_compression_dict_misses */,
1 /* expected_compression_dict_hits */,
0 /* expected_compression_dict_inserts */);
}
}
static void ClearCache(Cache* cache) {
auto roles = CopyCacheDeleterRoleMap();
std::deque<std::string> keys;
Cache::ApplyToAllEntriesOptions opts;
auto callback = [&](const Slice& key, void* /*value*/, size_t /*charge*/,
Cache::DeleterFn deleter) {
if (roles.find(deleter) == roles.end()) {
// Keep the stats collector
return;
}
keys.push_back(key.ToString());
};
cache->ApplyToAllEntries(callback, opts);
for (auto& k : keys) {
cache->Erase(k);
}
}
TEST_F(DBBlockCacheTest, CacheEntryRoleStats) {
const size_t capacity = size_t{1} << 25;
int iterations_tested = 0;
for (bool partition : {false, true}) {
for (std::shared_ptr<Cache> cache :
{NewLRUCache(capacity), NewClockCache(capacity),
NewFastLRUCache(capacity)}) {
if (!cache) {
// Skip clock cache when not supported
continue;
}
++iterations_tested;
Options options = CurrentOptions();
SetTimeElapseOnlySleepOnReopen(&options);
options.create_if_missing = true;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
options.max_open_files = 13;
options.table_cache_numshardbits = 0;
// If this wakes up, it could interfere with test
options.stats_dump_period_sec = 0;
BlockBasedTableOptions table_options;
table_options.block_cache = cache;
table_options.cache_index_and_filter_blocks = true;
table_options.filter_policy.reset(NewBloomFilterPolicy(50));
if (partition) {
table_options.index_type = BlockBasedTableOptions::kTwoLevelIndexSearch;
table_options.partition_filters = true;
}
table_options.metadata_cache_options.top_level_index_pinning =
PinningTier::kNone;
table_options.metadata_cache_options.partition_pinning =
PinningTier::kNone;
table_options.metadata_cache_options.unpartitioned_pinning =
PinningTier::kNone;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
DestroyAndReopen(options);
// Create a new table.
ASSERT_OK(Put("foo", "value"));
ASSERT_OK(Put("bar", "value"));
ASSERT_OK(Flush());
ASSERT_OK(Put("zfoo", "value"));
ASSERT_OK(Put("zbar", "value"));
ASSERT_OK(Flush());
ASSERT_EQ(2, NumTableFilesAtLevel(0));
// Fresh cache
ClearCache(cache.get());
std::array<size_t, kNumCacheEntryRoles> expected{};
// For CacheEntryStatsCollector
expected[static_cast<size_t>(CacheEntryRole::kMisc)] = 1;
EXPECT_EQ(expected, GetCacheEntryRoleCountsBg());
std::array<size_t, kNumCacheEntryRoles> prev_expected = expected;
// First access only filters
ASSERT_EQ("NOT_FOUND", Get("different from any key added"));
expected[static_cast<size_t>(CacheEntryRole::kFilterBlock)] += 2;
if (partition) {
expected[static_cast<size_t>(CacheEntryRole::kFilterMetaBlock)] += 2;
}
// Within some time window, we will get cached entry stats
EXPECT_EQ(prev_expected, GetCacheEntryRoleCountsBg());
// Not enough to force a miss
env_->MockSleepForSeconds(45);
EXPECT_EQ(prev_expected, GetCacheEntryRoleCountsBg());
// Enough to force a miss
env_->MockSleepForSeconds(601);
EXPECT_EQ(expected, GetCacheEntryRoleCountsBg());
// Now access index and data block
ASSERT_EQ("value", Get("foo"));
expected[static_cast<size_t>(CacheEntryRole::kIndexBlock)]++;
if (partition) {
// top-level
expected[static_cast<size_t>(CacheEntryRole::kIndexBlock)]++;
}
expected[static_cast<size_t>(CacheEntryRole::kDataBlock)]++;
// Enough to force a miss
env_->MockSleepForSeconds(601);
// But inject a simulated long scan so that we need a longer
// interval to force a miss next time.
SyncPoint::GetInstance()->SetCallBack(
"CacheEntryStatsCollector::GetStats:AfterApplyToAllEntries",
[this](void*) {
// To spend no more than 0.2% of time scanning, we would need
// interval of at least 10000s
env_->MockSleepForSeconds(20);
});
SyncPoint::GetInstance()->EnableProcessing();
EXPECT_EQ(expected, GetCacheEntryRoleCountsBg());
prev_expected = expected;
SyncPoint::GetInstance()->DisableProcessing();
SyncPoint::GetInstance()->ClearAllCallBacks();
// The same for other file
ASSERT_EQ("value", Get("zfoo"));
expected[static_cast<size_t>(CacheEntryRole::kIndexBlock)]++;
if (partition) {
// top-level
expected[static_cast<size_t>(CacheEntryRole::kIndexBlock)]++;
}
expected[static_cast<size_t>(CacheEntryRole::kDataBlock)]++;
// Because of the simulated long scan, this is not enough to force
// a miss
env_->MockSleepForSeconds(601);
EXPECT_EQ(prev_expected, GetCacheEntryRoleCountsBg());
// But this is enough
env_->MockSleepForSeconds(10000);
EXPECT_EQ(expected, GetCacheEntryRoleCountsBg());
prev_expected = expected;
// Also check the GetProperty interface
std::map<std::string, std::string> values;
ASSERT_TRUE(
db_->GetMapProperty(DB::Properties::kBlockCacheEntryStats, &values));
for (size_t i = 0; i < kNumCacheEntryRoles; ++i) {
auto role = static_cast<CacheEntryRole>(i);
EXPECT_EQ(ToString(expected[i]),
values[BlockCacheEntryStatsMapKeys::EntryCount(role)]);
}
// Add one for kWriteBuffer
{
WriteBufferManager wbm(size_t{1} << 20, cache);
wbm.ReserveMem(1024);
expected[static_cast<size_t>(CacheEntryRole::kWriteBuffer)]++;
// Now we check that the GetProperty interface is more agressive about
// re-scanning stats, but not totally aggressive.
// Within some time window, we will get cached entry stats
env_->MockSleepForSeconds(1);
EXPECT_EQ(ToString(prev_expected[static_cast<size_t>(
CacheEntryRole::kWriteBuffer)]),
values[BlockCacheEntryStatsMapKeys::EntryCount(
CacheEntryRole::kWriteBuffer)]);
// Not enough for a "background" miss but enough for a "foreground" miss
env_->MockSleepForSeconds(45);
ASSERT_TRUE(db_->GetMapProperty(DB::Properties::kBlockCacheEntryStats,
&values));
EXPECT_EQ(
ToString(
expected[static_cast<size_t>(CacheEntryRole::kWriteBuffer)]),
values[BlockCacheEntryStatsMapKeys::EntryCount(
CacheEntryRole::kWriteBuffer)]);
}
prev_expected = expected;
// With collector pinned in cache, we should be able to hit
// even if the cache is full
ClearCache(cache.get());
Cache::Handle* h = nullptr;
ASSERT_OK(cache->Insert("Fill-it-up", nullptr, capacity + 1,
GetNoopDeleterForRole<CacheEntryRole::kMisc>(),
&h, Cache::Priority::HIGH));
ASSERT_GT(cache->GetUsage(), cache->GetCapacity());
expected = {};
// For CacheEntryStatsCollector
expected[static_cast<size_t>(CacheEntryRole::kMisc)] = 1;
// For Fill-it-up
expected[static_cast<size_t>(CacheEntryRole::kMisc)]++;
// Still able to hit on saved stats
EXPECT_EQ(prev_expected, GetCacheEntryRoleCountsBg());
// Enough to force a miss
env_->MockSleepForSeconds(1000);
EXPECT_EQ(expected, GetCacheEntryRoleCountsBg());
cache->Release(h);
// Now we test that the DB mutex is not held during scans, for the ways
// we know how to (possibly) trigger them. Without a better good way to
// check this, we simply inject an acquire & release of the DB mutex
// deep in the stat collection code. If we were already holding the
// mutex, that is UB that would at least be found by TSAN.
int scan_count = 0;
SyncPoint::GetInstance()->SetCallBack(
"CacheEntryStatsCollector::GetStats:AfterApplyToAllEntries",
[this, &scan_count](void*) {
dbfull()->TEST_LockMutex();
dbfull()->TEST_UnlockMutex();
++scan_count;
});
SyncPoint::GetInstance()->EnableProcessing();
// Different things that might trigger a scan, with mock sleeps to
// force a miss.
env_->MockSleepForSeconds(10000);
dbfull()->DumpStats();
ASSERT_EQ(scan_count, 1);
env_->MockSleepForSeconds(10000);
ASSERT_TRUE(
db_->GetMapProperty(DB::Properties::kBlockCacheEntryStats, &values));
ASSERT_EQ(scan_count, 2);
env_->MockSleepForSeconds(10000);
std::string value_str;
ASSERT_TRUE(
db_->GetProperty(DB::Properties::kBlockCacheEntryStats, &value_str));
ASSERT_EQ(scan_count, 3);
env_->MockSleepForSeconds(10000);
ASSERT_TRUE(db_->GetProperty(DB::Properties::kCFStats, &value_str));
// To match historical speed, querying this property no longer triggers
// a scan, even if results are old. But periodic dump stats should keep
// things reasonably updated.
ASSERT_EQ(scan_count, /*unchanged*/ 3);
SyncPoint::GetInstance()->DisableProcessing();
SyncPoint::GetInstance()->ClearAllCallBacks();
}
EXPECT_GE(iterations_tested, 1);
}
}
#endif // ROCKSDB_LITE
class DBBlockCacheKeyTest
: public DBTestBase,
public testing::WithParamInterface<std::tuple<bool, bool>> {
public:
DBBlockCacheKeyTest()
: DBTestBase("db_block_cache_test", /*env_do_fsync=*/false) {}
void SetUp() override {
use_compressed_cache_ = std::get<0>(GetParam());
exclude_file_numbers_ = std::get<1>(GetParam());
}
bool use_compressed_cache_;
bool exclude_file_numbers_;
};
// Disable LinkFile so that we can physically copy a DB using Checkpoint.
// Disable file GetUniqueId to enable stable cache keys.
class StableCacheKeyTestFS : public FaultInjectionTestFS {
public:
explicit StableCacheKeyTestFS(const std::shared_ptr<FileSystem>& base)
: FaultInjectionTestFS(base) {
SetFailGetUniqueId(true);
}
virtual ~StableCacheKeyTestFS() override {}
IOStatus LinkFile(const std::string&, const std::string&, const IOOptions&,
IODebugContext*) override {
return IOStatus::NotSupported("Disabled");
}
};
TEST_P(DBBlockCacheKeyTest, StableCacheKeys) {
std::shared_ptr<StableCacheKeyTestFS> test_fs{
new StableCacheKeyTestFS(env_->GetFileSystem())};
std::unique_ptr<CompositeEnvWrapper> test_env{
new CompositeEnvWrapper(env_, test_fs)};
Options options = CurrentOptions();
options.create_if_missing = true;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
options.env = test_env.get();
BlockBasedTableOptions table_options;
int key_count = 0;
uint64_t expected_stat = 0;
std::function<void()> verify_stats;
if (use_compressed_cache_) {
if (!Snappy_Supported()) {
ROCKSDB_GTEST_SKIP("Compressed cache test requires snappy support");
return;
}
options.compression = CompressionType::kSnappyCompression;
table_options.no_block_cache = true;
table_options.block_cache_compressed = NewLRUCache(1 << 25, 0, false);
verify_stats = [&options, &expected_stat] {
// One for ordinary SST file and one for external SST file
ASSERT_EQ(expected_stat,
options.statistics->getTickerCount(BLOCK_CACHE_COMPRESSED_ADD));
};
} else {
table_options.cache_index_and_filter_blocks = true;
table_options.block_cache = NewLRUCache(1 << 25, 0, false);
verify_stats = [&options, &expected_stat] {
ASSERT_EQ(expected_stat,
options.statistics->getTickerCount(BLOCK_CACHE_DATA_ADD));
ASSERT_EQ(expected_stat,
options.statistics->getTickerCount(BLOCK_CACHE_INDEX_ADD));
ASSERT_EQ(expected_stat,
options.statistics->getTickerCount(BLOCK_CACHE_FILTER_ADD));
};
}
table_options.filter_policy.reset(NewBloomFilterPolicy(10, false));
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
CreateAndReopenWithCF({"koko"}, options);
if (exclude_file_numbers_) {
// Simulate something like old behavior without file numbers in properties.
// This is a "control" side of the test that also ensures safely degraded
// behavior on old files.
ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
"BlockBasedTableBuilder::BlockBasedTableBuilder:PreSetupBaseCacheKey",
[&](void* arg) {
TableProperties* props = reinterpret_cast<TableProperties*>(arg);
props->orig_file_number = 0;
});
ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
}
std::function<void()> perform_gets = [&key_count, &expected_stat, this]() {
if (exclude_file_numbers_) {
// No cache key reuse should happen, because we can't rely on current
// file number being stable
expected_stat += key_count;
} else {
// Cache keys should be stable
expected_stat = key_count;
}
for (int i = 0; i < key_count; ++i) {
ASSERT_EQ(Get(1, Key(i)), "abc");
}
};
// Ordinary SST files with same session id
const std::string something_compressible(500U, 'x');
for (int i = 0; i < 2; ++i) {
ASSERT_OK(Put(1, Key(key_count), "abc"));
ASSERT_OK(Put(1, Key(key_count) + "a", something_compressible));
ASSERT_OK(Flush(1));
++key_count;
}
#ifndef ROCKSDB_LITE
// Save an export of those ordinary SST files for later
std::string export_files_dir = dbname_ + "/exported";
ExportImportFilesMetaData* metadata_ptr_ = nullptr;
Checkpoint* checkpoint;
ASSERT_OK(Checkpoint::Create(db_, &checkpoint));
ASSERT_OK(checkpoint->ExportColumnFamily(handles_[1], export_files_dir,
&metadata_ptr_));
ASSERT_NE(metadata_ptr_, nullptr);
delete checkpoint;
checkpoint = nullptr;
// External SST files with same session id
SstFileWriter sst_file_writer(EnvOptions(), options);
std::vector<std::string> external;
for (int i = 0; i < 2; ++i) {
std::string f = dbname_ + "/external" + ToString(i) + ".sst";
external.push_back(f);
ASSERT_OK(sst_file_writer.Open(f));
ASSERT_OK(sst_file_writer.Put(Key(key_count), "abc"));
ASSERT_OK(
sst_file_writer.Put(Key(key_count) + "a", something_compressible));
++key_count;
ExternalSstFileInfo external_info;
ASSERT_OK(sst_file_writer.Finish(&external_info));
IngestExternalFileOptions ingest_opts;
ASSERT_OK(db_->IngestExternalFile(handles_[1], {f}, ingest_opts));
}
if (exclude_file_numbers_) {
// FIXME(peterd): figure out where these extra ADDs are coming from
options.statistics->recordTick(BLOCK_CACHE_COMPRESSED_ADD,
uint64_t{0} - uint64_t{2});
}
#endif
perform_gets();
verify_stats();
// Make sure we can cache hit after re-open
ReopenWithColumnFamilies({"default", "koko"}, options);
perform_gets();
verify_stats();
// Make sure we can cache hit even on a full copy of the DB. Using
// StableCacheKeyTestFS, Checkpoint will resort to full copy not hard link.
// (Checkpoint not available in LITE mode to test this.)
#ifndef ROCKSDB_LITE
auto db_copy_name = dbname_ + "-copy";
ASSERT_OK(Checkpoint::Create(db_, &checkpoint));
ASSERT_OK(checkpoint->CreateCheckpoint(db_copy_name));
delete checkpoint;
Close();
Destroy(options);
// Switch to the DB copy
SaveAndRestore<std::string> save_dbname(&dbname_, db_copy_name);
ReopenWithColumnFamilies({"default", "koko"}, options);
perform_gets();
verify_stats();
// And ensure that re-importing + ingesting the same files into a
// different DB uses same cache keys
DestroyAndReopen(options);
ColumnFamilyHandle* cfh = nullptr;
ASSERT_OK(db_->CreateColumnFamilyWithImport(ColumnFamilyOptions(), "yoyo",
ImportColumnFamilyOptions(),
*metadata_ptr_, &cfh));
ASSERT_NE(cfh, nullptr);
delete cfh;
cfh = nullptr;
delete metadata_ptr_;
metadata_ptr_ = nullptr;
DestroyDB(export_files_dir, options);
ReopenWithColumnFamilies({"default", "yoyo"}, options);
IngestExternalFileOptions ingest_opts;
ASSERT_OK(db_->IngestExternalFile(handles_[1], {external}, ingest_opts));
perform_gets();
verify_stats();
#endif // !ROCKSDB_LITE
Close();
Destroy(options);
ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
}
class CacheKeyTest : public testing::Test {
public:
void SetupStableBase() {
// Like SemiStructuredUniqueIdGen::GenerateNext
tp_.db_session_id = EncodeSessionId(base_session_upper_,
base_session_lower_ ^ session_counter_);
tp_.db_id = ToString(db_id_);
tp_.orig_file_number = file_number_;
bool is_stable;
std::string cur_session_id = ""; // ignored
uint64_t cur_file_number = 42; // ignored
BlockBasedTable::SetupBaseCacheKey(&tp_, cur_session_id, cur_file_number,
file_size_, &base_cache_key_,
&is_stable);
ASSERT_TRUE(is_stable);
}
CacheKey WithOffset(uint64_t offset) {
return BlockBasedTable::GetCacheKey(base_cache_key_,
BlockHandle(offset, /*size*/ 5));
}
protected:
OffsetableCacheKey base_cache_key_;
TableProperties tp_;
uint64_t file_size_ = 0;
uint64_t base_session_upper_ = 0;
uint64_t base_session_lower_ = 0;
uint64_t session_counter_ = 0;
uint64_t file_number_ = 0;
uint64_t db_id_ = 0;
};
namespace {
template <typename T>
int CountBitsDifferent(const T& t1, const T& t2) {
int diff = 0;
const uint8_t* p1 = reinterpret_cast<const uint8_t*>(&t1);
const uint8_t* p2 = reinterpret_cast<const uint8_t*>(&t2);
static_assert(sizeof(*p1) == 1, "Expecting uint8_t byte");
for (size_t i = 0; i < sizeof(T); ++i) {
diff += BitsSetToOne(p1[i] ^ p2[i]);
}
return diff;
}
} // namespace
TEST_F(CacheKeyTest, DBImplSessionIdStructure) {
// We have to generate our own session IDs for simulation purposes in other
// tests. Here we verify that the DBImpl implementation seems to match
// our construction here, by using lowest XORed-in bits for "session
// counter."
std::string session_id1 = DBImpl::GenerateDbSessionId(/*env*/ nullptr);
std::string session_id2 = DBImpl::GenerateDbSessionId(/*env*/ nullptr);
uint64_t upper1, upper2, lower1, lower2;
ASSERT_OK(DecodeSessionId(session_id1, &upper1, &lower1));
ASSERT_OK(DecodeSessionId(session_id2, &upper2, &lower2));
// Because generated in same process
ASSERT_EQ(upper1, upper2);
// Unless we generate > 4 billion session IDs in this process...
ASSERT_EQ(Upper32of64(lower1), Upper32of64(lower2));
// But they must be different somewhere
ASSERT_NE(Lower32of64(lower1), Lower32of64(lower2));
}
TEST_F(CacheKeyTest, StandardEncodingLimit) {
base_session_upper_ = 1234;
base_session_lower_ = 5678;
session_counter_ = 42;
file_number_ = 42;
db_id_ = 1234;
file_size_ = 42;
SetupStableBase();
CacheKey ck1;
ASSERT_TRUE(ck1.IsEmpty());
ck1 = WithOffset(0);
ASSERT_FALSE(ck1.IsEmpty());
// Should use same encoding
file_size_ = BlockBasedTable::kMaxFileSizeStandardEncoding;
SetupStableBase();
CacheKey ck2 = WithOffset(0);
ASSERT_EQ(CountBitsDifferent(ck1, ck2), 0);
// Should use different encoding
++file_size_;
SetupStableBase();
CacheKey ck3 = WithOffset(0);
ASSERT_GT(CountBitsDifferent(ck2, ck3), 0);
}
TEST_F(CacheKeyTest, Encodings) {
// Claim from cache_key.cc:
// In fact, if our SST files are all < 4TB (see
// BlockBasedTable::kMaxFileSizeStandardEncoding), then SST files generated
// in a single process are guaranteed to have unique cache keys, unless/until
// number session ids * max file number = 2**86, e.g. 1 trillion DB::Open in
// a single process and 64 trillion files generated.
// We can generalize that. For
// * z bits in maximum file size
// * n bits in maximum file number
// * s bits in maximum session counter
// uniqueness is guaranteed at least when all of these hold:
// * z + n + s <= 121 (128 - 2 meta + 2 offset trim - (8-1) byte granularity
// in encoding)
// * n + s <= 86 (encoding limitation)
// * s <= 62 (because of 2-bit metadata)
// We can verify this indirectly by how input bits get into the cache key,
// but we have to be mindful that for sufficiently large file sizes,
// different encodings might be used. But for cases mixing large and small
// files, we have to verify uniqueness between encodings.
// Going through all combinations would be a little expensive, so we test
// only one random "stripe" of the configuration space per run.
constexpr uint32_t kStripeBits = 8;
constexpr uint32_t kStripeMask = (uint32_t{1} << kStripeBits) - 1;
// Also cycle through stripes on repeated runs (not thread safe)
static uint32_t stripe =
static_cast<uint32_t>(std::random_device{}()) & kStripeMask;
stripe = (stripe + 1) & kStripeMask;
fprintf(stderr, "%u\n", stripe);
// We are going to randomly initialize some values which *should* not affect
// result
Random64 r{std::random_device{}()};
int max_num_encodings = 0;
uint32_t config_num = 0;
uint32_t session_counter_bits, file_number_bits, max_file_size_bits;
// Inner loop body, used later in a loop over configurations
auto TestConfig = [&]() {
base_session_upper_ = r.Next();
base_session_lower_ = r.Next();
session_counter_ = r.Next();
if (session_counter_bits < 64) {
// Avoid shifting UB
session_counter_ = session_counter_ >> 1 >> (63 - session_counter_bits);
}
file_number_ = r.Next() >> (64 - file_number_bits);
// Need two bits set to avoid temporary zero below
if (BitsSetToOne(file_number_) < 2) {
file_number_ = 3;
}
db_id_ = r.Next();
// Work-around clang-analyzer which thinks empty last_base is garbage
CacheKey last_base = CacheKey::CreateUniqueForProcessLifetime();
std::unordered_set<std::string> seen;
int num_encodings = 0;
// Loop over encodings by increasing file size bits
for (uint32_t file_size_bits = 1; file_size_bits <= max_file_size_bits;
++file_size_bits) {
file_size_ = uint64_t{1} << (file_size_bits - 1);
SetupStableBase();
CacheKey new_base = WithOffset(0);
if (CountBitsDifferent(last_base, new_base) == 0) {
// Same as previous encoding
continue;
}
// New encoding
++num_encodings;
ASSERT_TRUE(seen.insert(new_base.AsSlice().ToString()).second);
last_base = new_base;
for (uint32_t i = 0; i < file_size_bits; ++i) {
CacheKey ck = WithOffset(uint64_t{1} << i);
if (i < 2) {
// These cases are not relevant and optimized by dropping two
// lowest bits because there's always at least 5 bytes between
// blocks.
ASSERT_EQ(CountBitsDifferent(ck, new_base), 0);
} else {
// Normal case
// 1 bit different from base and never been seen implies the bit
// is encoded into cache key without overlapping other structured
// data.
ASSERT_EQ(CountBitsDifferent(ck, new_base), 1);
ASSERT_TRUE(seen.insert(ck.AsSlice().ToString()).second);
}
}
for (uint32_t i = 0; i < session_counter_bits; ++i) {
SaveAndRestore<uint64_t> tmp(&session_counter_,
session_counter_ ^ (uint64_t{1} << i));
SetupStableBase();
CacheKey ck = WithOffset(0);
ASSERT_EQ(CountBitsDifferent(ck, new_base), 1);
ASSERT_TRUE(seen.insert(ck.AsSlice().ToString()).second);
}
for (uint32_t i = 0; i < file_number_bits; ++i) {
SaveAndRestore<uint64_t> tmp(&file_number_,
file_number_ ^ (uint64_t{1} << i));
SetupStableBase();
CacheKey ck = WithOffset(0);
ASSERT_EQ(CountBitsDifferent(ck, new_base), 1);
ASSERT_TRUE(seen.insert(ck.AsSlice().ToString()).second);
}
max_num_encodings = std::max(max_num_encodings, num_encodings);
}
};
// Loop over configurations and test those in stripe
for (session_counter_bits = 0; session_counter_bits <= 62;
++session_counter_bits) {
uint32_t max_file_number_bits =
std::min(uint32_t{64}, uint32_t{86} - session_counter_bits);
// Start with 2 to avoid file_number_ == 0 in testing
for (file_number_bits = 2; file_number_bits <= max_file_number_bits;
++file_number_bits) {
uint32_t max_max_file_size_bits =
std::min(uint32_t{64},
uint32_t{121} - file_number_bits - session_counter_bits);
for (max_file_size_bits = 1; max_file_size_bits <= max_max_file_size_bits;
++max_file_size_bits) {
if ((config_num++ & kStripeMask) == stripe) {
TestConfig();
}
}
}
}
// Make sure the current implementation is exercised
ASSERT_EQ(max_num_encodings, 4);
}
INSTANTIATE_TEST_CASE_P(DBBlockCacheKeyTest, DBBlockCacheKeyTest,
::testing::Combine(::testing::Bool(),
::testing::Bool()));
class DBBlockCachePinningTest
: public DBTestBase,
public testing::WithParamInterface<
std::tuple<bool, PinningTier, PinningTier, PinningTier>> {
public:
DBBlockCachePinningTest()
: DBTestBase("db_block_cache_test", /*env_do_fsync=*/false) {}
void SetUp() override {
partition_index_and_filters_ = std::get<0>(GetParam());
top_level_index_pinning_ = std::get<1>(GetParam());
partition_pinning_ = std::get<2>(GetParam());
unpartitioned_pinning_ = std::get<3>(GetParam());
}
bool partition_index_and_filters_;
PinningTier top_level_index_pinning_;
PinningTier partition_pinning_;
PinningTier unpartitioned_pinning_;
};
TEST_P(DBBlockCachePinningTest, TwoLevelDB) {
// Creates one file in L0 and one file in L1. Both files have enough data that
// their index and filter blocks are partitioned. The L1 file will also have
// a compression dictionary (those are trained only during compaction), which
// must be unpartitioned.
const int kKeySize = 32;
const int kBlockSize = 128;
const int kNumBlocksPerFile = 128;
const int kNumKeysPerFile = kBlockSize * kNumBlocksPerFile / kKeySize;
Options options = CurrentOptions();
// `kNoCompression` makes the unit test more portable. But it relies on the
// current behavior of persisting/accessing dictionary even when there's no
// (de)compression happening, which seems fairly likely to change over time.
options.compression = kNoCompression;
options.compression_opts.max_dict_bytes = 4 << 10;
options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
BlockBasedTableOptions table_options;
table_options.block_cache = NewLRUCache(1 << 20 /* capacity */);
table_options.block_size = kBlockSize;
table_options.metadata_block_size = kBlockSize;
table_options.cache_index_and_filter_blocks = true;
table_options.metadata_cache_options.top_level_index_pinning =
top_level_index_pinning_;
table_options.metadata_cache_options.partition_pinning = partition_pinning_;
table_options.metadata_cache_options.unpartitioned_pinning =
unpartitioned_pinning_;
table_options.filter_policy.reset(
NewBloomFilterPolicy(10 /* bits_per_key */));
if (partition_index_and_filters_) {
table_options.index_type =
BlockBasedTableOptions::IndexType::kTwoLevelIndexSearch;
table_options.partition_filters = true;
}
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
Reopen(options);
Random rnd(301);
for (int i = 0; i < 2; ++i) {
for (int j = 0; j < kNumKeysPerFile; ++j) {
ASSERT_OK(Put(Key(i * kNumKeysPerFile + j), rnd.RandomString(kKeySize)));
}
ASSERT_OK(Flush());
if (i == 0) {
// Prevent trivial move so file will be rewritten with dictionary and
// reopened with L1's pinning settings.
CompactRangeOptions cro;
cro.bottommost_level_compaction = BottommostLevelCompaction::kForce;
ASSERT_OK(db_->CompactRange(cro, nullptr, nullptr));
}
}
// Clear all unpinned blocks so unpinned blocks will show up as cache misses
// when reading a key from a file.
table_options.block_cache->EraseUnRefEntries();
// Get base cache values
uint64_t filter_misses = TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS);
uint64_t index_misses = TestGetTickerCount(options, BLOCK_CACHE_INDEX_MISS);
uint64_t compression_dict_misses =
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSION_DICT_MISS);
// Read a key from the L0 file
Get(Key(kNumKeysPerFile));
uint64_t expected_filter_misses = filter_misses;
uint64_t expected_index_misses = index_misses;
uint64_t expected_compression_dict_misses = compression_dict_misses;
if (partition_index_and_filters_) {
if (top_level_index_pinning_ == PinningTier::kNone) {
++expected_filter_misses;
++expected_index_misses;
}
if (partition_pinning_ == PinningTier::kNone) {
++expected_filter_misses;
++expected_index_misses;
}
} else {
if (unpartitioned_pinning_ == PinningTier::kNone) {
++expected_filter_misses;
++expected_index_misses;
}
}
if (unpartitioned_pinning_ == PinningTier::kNone) {
++expected_compression_dict_misses;
}
ASSERT_EQ(expected_filter_misses,
TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS));
ASSERT_EQ(expected_index_misses,
TestGetTickerCount(options, BLOCK_CACHE_INDEX_MISS));
ASSERT_EQ(expected_compression_dict_misses,
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSION_DICT_MISS));
// Clear all unpinned blocks so unpinned blocks will show up as cache misses
// when reading a key from a file.
table_options.block_cache->EraseUnRefEntries();
// Read a key from the L1 file
Get(Key(0));
if (partition_index_and_filters_) {
if (top_level_index_pinning_ == PinningTier::kNone ||
top_level_index_pinning_ == PinningTier::kFlushedAndSimilar) {
++expected_filter_misses;
++expected_index_misses;
}
if (partition_pinning_ == PinningTier::kNone ||
partition_pinning_ == PinningTier::kFlushedAndSimilar) {
++expected_filter_misses;
++expected_index_misses;
}
} else {
if (unpartitioned_pinning_ == PinningTier::kNone ||
unpartitioned_pinning_ == PinningTier::kFlushedAndSimilar) {
++expected_filter_misses;
++expected_index_misses;
}
}
if (unpartitioned_pinning_ == PinningTier::kNone ||
unpartitioned_pinning_ == PinningTier::kFlushedAndSimilar) {
++expected_compression_dict_misses;
}
ASSERT_EQ(expected_filter_misses,
TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS));
ASSERT_EQ(expected_index_misses,
TestGetTickerCount(options, BLOCK_CACHE_INDEX_MISS));
ASSERT_EQ(expected_compression_dict_misses,
TestGetTickerCount(options, BLOCK_CACHE_COMPRESSION_DICT_MISS));
}
INSTANTIATE_TEST_CASE_P(
DBBlockCachePinningTest, DBBlockCachePinningTest,
::testing::Combine(
::testing::Bool(),
::testing::Values(PinningTier::kNone, PinningTier::kFlushedAndSimilar,
PinningTier::kAll),
::testing::Values(PinningTier::kNone, PinningTier::kFlushedAndSimilar,
PinningTier::kAll),
::testing::Values(PinningTier::kNone, PinningTier::kFlushedAndSimilar,
PinningTier::kAll)));
} // namespace ROCKSDB_NAMESPACE
int main(int argc, char** argv) {
ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
Reference in New Issue View Git Blame Copy Permalink