rocksdb/db/db_block_cache_test.cc
Akanksha Mahajan 8b2f60b668 Cache warming blocks during flush (#8561)
Summary:
Insert warm blocks  (data, uncompressed dict, index and filter blocks) during flush in Block cache which is enabled under option BlockBasedTableOptions.prepopulate_block_cache.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8561

Test Plan: Added unit test

Reviewed By: anand1976

Differential Revision: D29773411

Pulled By: akankshamahajan15

fbshipit-source-id: 6631123c10134340ef0bd7e90baafaa6deba0e66
2021-08-03 12:44:15 -07:00

1418 lines
54 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#include <cstdlib>
#include <memory>
#include "cache/cache_entry_roles.h"
#include "cache/lru_cache.h"
#include "db/column_family.h"
#include "db/db_test_util.h"
#include "port/stack_trace.h"
#include "rocksdb/table.h"
#include "util/compression.h"
#include "util/random.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);
}
#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));
}
}
// This test cache all types of blocks during flush.
TEST_F(DBBlockCacheTest, 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);
table_options.cache_index_and_filter_blocks = true;
table_options.prepopulate_block_cache =
BlockBasedTableOptions::PrepopulateBlockCache::kFlushOnly;
table_options.filter_policy.reset(NewBloomFilterPolicy(10, false));
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
DestroyAndReopen(options);
std::string value(kValueSize, 'a');
for (size_t i = 1; i < 2; i++) {
ASSERT_OK(Put(ToString(i), value));
ASSERT_OK(Flush());
ASSERT_EQ(i, options.statistics->getTickerCount(BLOCK_CACHE_DATA_ADD));
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));
ASSERT_EQ(0, options.statistics->getTickerCount(BLOCK_CACHE_FILTER_MISS));
ASSERT_EQ(i * 2,
options.statistics->getTickerCount(BLOCK_CACHE_FILTER_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)}) {
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)}) {
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));
EXPECT_EQ(
ToString(expected[static_cast<size_t>(CacheEntryRole::kIndexBlock)]),
values["count.index-block"]);
EXPECT_EQ(
ToString(expected[static_cast<size_t>(CacheEntryRole::kDataBlock)]),
values["count.data-block"]);
EXPECT_EQ(
ToString(expected[static_cast<size_t>(CacheEntryRole::kFilterBlock)]),
values["count.filter-block"]);
EXPECT_EQ(
ToString(
prev_expected[static_cast<size_t>(CacheEntryRole::kWriteBuffer)]),
values["count.write-buffer"]);
EXPECT_EQ(ToString(expected[static_cast<size_t>(CacheEntryRole::kMisc)]),
values["count.misc"]);
// 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["count.write-buffer"]);
// 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["count.write-buffer"]);
}
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 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();
}