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rocksdb/utilities/simulator_cache/cache_simulator_test.cc
haoyuhuang 6e78fe3c8d Pysim more algorithms (#5644) 
Summary:
This PR adds four more eviction policies.
- OPT [1]
- Hyperbolic caching [2]
- ARC [3]
- GreedyDualSize [4]

[1] L. A. Belady. 1966. A Study of Replacement Algorithms for a Virtual-storage Computer. IBM Syst. J. 5, 2 (June 1966), 78-101. DOI=http://dx.doi.org/10.1147/sj.52.0078
[2] Aaron Blankstein, Siddhartha Sen, and Michael J. Freedman. 2017. Hyperbolic caching: flexible caching for web applications. In Proceedings of the 2017 USENIX Conference on Usenix Annual Technical Conference (USENIX ATC '17). USENIX Association, Berkeley, CA, USA, 499-511.
[3] Nimrod Megiddo and Dharmendra S. Modha. 2003. ARC: A Self-Tuning, Low Overhead Replacement Cache. In Proceedings of the 2nd USENIX Conference on File and Storage Technologies (FAST '03). USENIX Association, Berkeley, CA, USA, 115-130.
[4] N. Young. The k-server dual and loose competitiveness for paging. Algorithmica, June 1994, vol. 11,(no.6):525-41. Rewritten version of ''On-line caching as cache size varies'', in The 2nd Annual ACM-SIAM Symposium on Discrete Algorithms, 241-250, 1991.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5644

Differential Revision: D16548817

Pulled By: HaoyuHuang

fbshipit-source-id: 838f76db9179f07911abaab46c97e1c929cfcd63
2019-08-06 18:50:59 -07:00

492 lines
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// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "utilities/simulator_cache/cache_simulator.h"
#include <cstdlib>
#include "rocksdb/env.h"
#include "test_util/testharness.h"
#include "test_util/testutil.h"
namespace rocksdb {
namespace {
const std::string kBlockKeyPrefix = "test-block-";
const std::string kRefKeyPrefix = "test-get-";
const std::string kRefKeySequenceNumber = std::string(8, 'c');
const uint64_t kGetId = 1;
const uint64_t kGetBlockId = 100;
const uint64_t kCompactionBlockId = 1000;
const uint64_t kCacheSize = 1024 * 1024 * 1024;
const uint64_t kGhostCacheSize = 1024 * 1024;
} // namespace
class CacheSimulatorTest : public testing::Test {
public:
const size_t kNumBlocks = 5;
const size_t kValueSize = 1000;
CacheSimulatorTest() { env_ = rocksdb::Env::Default(); }
BlockCacheTraceRecord GenerateGetRecord(uint64_t getid) {
BlockCacheTraceRecord record;
record.block_type = TraceType::kBlockTraceDataBlock;
record.block_size = 4096;
record.block_key = kBlockKeyPrefix + std::to_string(kGetBlockId);
record.access_timestamp = env_->NowMicros();
record.cf_id = 0;
record.cf_name = "test";
record.caller = TableReaderCaller::kUserGet;
record.level = 6;
record.sst_fd_number = 0;
record.get_id = getid;
record.is_cache_hit = Boolean::kFalse;
record.no_insert = Boolean::kFalse;
record.referenced_key =
kRefKeyPrefix + std::to_string(kGetId) + kRefKeySequenceNumber;
record.referenced_key_exist_in_block = Boolean::kTrue;
record.referenced_data_size = 100;
record.num_keys_in_block = 300;
return record;
}
BlockCacheTraceRecord GenerateCompactionRecord() {
BlockCacheTraceRecord record;
record.block_type = TraceType::kBlockTraceDataBlock;
record.block_size = 4096;
record.block_key = kBlockKeyPrefix + std::to_string(kCompactionBlockId);
record.access_timestamp = env_->NowMicros();
record.cf_id = 0;
record.cf_name = "test";
record.caller = TableReaderCaller::kCompaction;
record.level = 6;
record.sst_fd_number = kCompactionBlockId;
record.is_cache_hit = Boolean::kFalse;
record.no_insert = Boolean::kTrue;
return record;
}
void AssertCache(std::shared_ptr<Cache> sim_cache,
const MissRatioStats& miss_ratio_stats,
uint64_t expected_usage, uint64_t expected_num_accesses,
uint64_t expected_num_misses,
std::vector<std::string> blocks,
std::vector<std::string> keys) {
EXPECT_EQ(expected_usage, sim_cache->GetUsage());
EXPECT_EQ(expected_num_accesses, miss_ratio_stats.total_accesses());
EXPECT_EQ(expected_num_misses, miss_ratio_stats.total_misses());
for (auto const& block : blocks) {
auto handle = sim_cache->Lookup(block);
EXPECT_NE(nullptr, handle);
sim_cache->Release(handle);
}
for (auto const& key : keys) {
std::string row_key = kRefKeyPrefix + key + kRefKeySequenceNumber;
auto handle =
sim_cache->Lookup("0_" + ExtractUserKey(row_key).ToString());
EXPECT_NE(nullptr, handle);
sim_cache->Release(handle);
}
}
Env* env_;
};
TEST_F(CacheSimulatorTest, GhostCache) {
const std::string key1 = "test1";
const std::string key2 = "test2";
std::unique_ptr<GhostCache> ghost_cache(new GhostCache(
NewLRUCache(/*capacity=*/kGhostCacheSize, /*num_shard_bits=*/1,
/*strict_capacity_limit=*/false,
/*high_pri_pool_ratio=*/0)));
EXPECT_FALSE(ghost_cache->Admit(key1));
EXPECT_TRUE(ghost_cache->Admit(key1));
EXPECT_TRUE(ghost_cache->Admit(key1));
EXPECT_FALSE(ghost_cache->Admit(key2));
EXPECT_TRUE(ghost_cache->Admit(key2));
}
TEST_F(CacheSimulatorTest, CacheSimulator) {
const BlockCacheTraceRecord& access = GenerateGetRecord(kGetId);
const BlockCacheTraceRecord& compaction_access = GenerateCompactionRecord();
std::shared_ptr<Cache> sim_cache =
NewLRUCache(/*capacity=*/kCacheSize, /*num_shard_bits=*/1,
/*strict_capacity_limit=*/false,
/*high_pri_pool_ratio=*/0);
std::unique_ptr<CacheSimulator> cache_simulator(
new CacheSimulator(nullptr, sim_cache));
cache_simulator->Access(access);
cache_simulator->Access(access);
ASSERT_EQ(2, cache_simulator->miss_ratio_stats().total_accesses());
ASSERT_EQ(50, cache_simulator->miss_ratio_stats().miss_ratio());
ASSERT_EQ(2, cache_simulator->miss_ratio_stats().user_accesses());
ASSERT_EQ(50, cache_simulator->miss_ratio_stats().user_miss_ratio());
cache_simulator->Access(compaction_access);
cache_simulator->Access(compaction_access);
ASSERT_EQ(4, cache_simulator->miss_ratio_stats().total_accesses());
ASSERT_EQ(75, cache_simulator->miss_ratio_stats().miss_ratio());
ASSERT_EQ(2, cache_simulator->miss_ratio_stats().user_accesses());
ASSERT_EQ(50, cache_simulator->miss_ratio_stats().user_miss_ratio());
cache_simulator->reset_counter();
ASSERT_EQ(0, cache_simulator->miss_ratio_stats().total_accesses());
ASSERT_EQ(-1, cache_simulator->miss_ratio_stats().miss_ratio());
auto handle = sim_cache->Lookup(access.block_key);
ASSERT_NE(nullptr, handle);
sim_cache->Release(handle);
handle = sim_cache->Lookup(compaction_access.block_key);
ASSERT_EQ(nullptr, handle);
}
TEST_F(CacheSimulatorTest, GhostCacheSimulator) {
const BlockCacheTraceRecord& access = GenerateGetRecord(kGetId);
std::unique_ptr<GhostCache> ghost_cache(new GhostCache(
NewLRUCache(/*capacity=*/kGhostCacheSize, /*num_shard_bits=*/1,
/*strict_capacity_limit=*/false,
/*high_pri_pool_ratio=*/0)));
std::unique_ptr<CacheSimulator> cache_simulator(new CacheSimulator(
std::move(ghost_cache),
NewLRUCache(/*capacity=*/kCacheSize, /*num_shard_bits=*/1,
/*strict_capacity_limit=*/false,
/*high_pri_pool_ratio=*/0)));
cache_simulator->Access(access);
cache_simulator->Access(access);
ASSERT_EQ(2, cache_simulator->miss_ratio_stats().total_accesses());
// Both of them will be miss since we have a ghost cache.
ASSERT_EQ(100, cache_simulator->miss_ratio_stats().miss_ratio());
}
TEST_F(CacheSimulatorTest, PrioritizedCacheSimulator) {
const BlockCacheTraceRecord& access = GenerateGetRecord(kGetId);
std::shared_ptr<Cache> sim_cache =
NewLRUCache(/*capacity=*/kCacheSize, /*num_shard_bits=*/1,
/*strict_capacity_limit=*/false,
/*high_pri_pool_ratio=*/0);
std::unique_ptr<PrioritizedCacheSimulator> cache_simulator(
new PrioritizedCacheSimulator(nullptr, sim_cache));
cache_simulator->Access(access);
cache_simulator->Access(access);
ASSERT_EQ(2, cache_simulator->miss_ratio_stats().total_accesses());
ASSERT_EQ(50, cache_simulator->miss_ratio_stats().miss_ratio());
auto handle = sim_cache->Lookup(access.block_key);
ASSERT_NE(nullptr, handle);
sim_cache->Release(handle);
}
TEST_F(CacheSimulatorTest, GhostPrioritizedCacheSimulator) {
const BlockCacheTraceRecord& access = GenerateGetRecord(kGetId);
std::unique_ptr<GhostCache> ghost_cache(new GhostCache(
NewLRUCache(/*capacity=*/kGhostCacheSize, /*num_shard_bits=*/1,
/*strict_capacity_limit=*/false,
/*high_pri_pool_ratio=*/0)));
std::unique_ptr<PrioritizedCacheSimulator> cache_simulator(
new PrioritizedCacheSimulator(
std::move(ghost_cache),
NewLRUCache(/*capacity=*/kCacheSize, /*num_shard_bits=*/1,
/*strict_capacity_limit=*/false,
/*high_pri_pool_ratio=*/0)));
cache_simulator->Access(access);
cache_simulator->Access(access);
ASSERT_EQ(2, cache_simulator->miss_ratio_stats().total_accesses());
// Both of them will be miss since we have a ghost cache.
ASSERT_EQ(100, cache_simulator->miss_ratio_stats().miss_ratio());
}
TEST_F(CacheSimulatorTest, HybridRowBlockCacheSimulator) {
uint64_t block_id = 100;
BlockCacheTraceRecord first_get = GenerateGetRecord(kGetId);
first_get.get_from_user_specified_snapshot = Boolean::kTrue;
BlockCacheTraceRecord second_get = GenerateGetRecord(kGetId + 1);
second_get.referenced_data_size = 0;
second_get.referenced_key_exist_in_block = Boolean::kFalse;
second_get.get_from_user_specified_snapshot = Boolean::kTrue;
BlockCacheTraceRecord third_get = GenerateGetRecord(kGetId + 2);
third_get.referenced_data_size = 0;
third_get.referenced_key_exist_in_block = Boolean::kFalse;
third_get.referenced_key = kRefKeyPrefix + "third_get";
// We didn't find the referenced key in the third get.
third_get.referenced_key_exist_in_block = Boolean::kFalse;
third_get.referenced_data_size = 0;
std::shared_ptr<Cache> sim_cache =
NewLRUCache(/*capacity=*/kCacheSize, /*num_shard_bits=*/1,
/*strict_capacity_limit=*/false,
/*high_pri_pool_ratio=*/0);
std::unique_ptr<HybridRowBlockCacheSimulator> cache_simulator(
new HybridRowBlockCacheSimulator(
nullptr, sim_cache, /*insert_blocks_row_kvpair_misses=*/true));
// The first get request accesses 10 blocks. We should only report 10 accesses
// and 100% miss.
for (uint32_t i = 0; i < 10; i++) {
first_get.block_key = kBlockKeyPrefix + std::to_string(block_id);
cache_simulator->Access(first_get);
block_id++;
}
ASSERT_EQ(10, cache_simulator->miss_ratio_stats().total_accesses());
ASSERT_EQ(100, cache_simulator->miss_ratio_stats().miss_ratio());
ASSERT_EQ(10, cache_simulator->miss_ratio_stats().user_accesses());
ASSERT_EQ(100, cache_simulator->miss_ratio_stats().user_miss_ratio());
auto handle =
sim_cache->Lookup(std::to_string(first_get.sst_fd_number) + "_" +
ExtractUserKey(first_get.referenced_key).ToString());
ASSERT_NE(nullptr, handle);
sim_cache->Release(handle);
for (uint32_t i = 100; i < block_id; i++) {
handle = sim_cache->Lookup(kBlockKeyPrefix + std::to_string(i));
ASSERT_NE(nullptr, handle);
sim_cache->Release(handle);
}
// The second get request accesses the same key. We should report 15
// access and 66% miss, 10 misses with 15 accesses.
// We do not consider these 5 block lookups as misses since the row hits the
// cache.
for (uint32_t i = 0; i < 5; i++) {
second_get.block_key = kBlockKeyPrefix + std::to_string(block_id);
cache_simulator->Access(second_get);
block_id++;
}
ASSERT_EQ(15, cache_simulator->miss_ratio_stats().total_accesses());
ASSERT_EQ(66, static_cast<uint64_t>(
cache_simulator->miss_ratio_stats().miss_ratio()));
ASSERT_EQ(15, cache_simulator->miss_ratio_stats().user_accesses());
ASSERT_EQ(66, static_cast<uint64_t>(
cache_simulator->miss_ratio_stats().user_miss_ratio()));
handle =
sim_cache->Lookup(std::to_string(second_get.sst_fd_number) + "_" +
ExtractUserKey(second_get.referenced_key).ToString());
ASSERT_NE(nullptr, handle);
sim_cache->Release(handle);
for (uint32_t i = 100; i < block_id; i++) {
handle = sim_cache->Lookup(kBlockKeyPrefix + std::to_string(i));
if (i < 110) {
ASSERT_NE(nullptr, handle) << i;
sim_cache->Release(handle);
} else {
ASSERT_EQ(nullptr, handle) << i;
}
}
// The third get on a different key and does not have a size.
// This key should not be inserted into the cache.
for (uint32_t i = 0; i < 5; i++) {
third_get.block_key = kBlockKeyPrefix + std::to_string(block_id);
cache_simulator->Access(third_get);
block_id++;
}
ASSERT_EQ(20, cache_simulator->miss_ratio_stats().total_accesses());
ASSERT_EQ(75, static_cast<uint64_t>(
cache_simulator->miss_ratio_stats().miss_ratio()));
ASSERT_EQ(20, cache_simulator->miss_ratio_stats().user_accesses());
ASSERT_EQ(75, static_cast<uint64_t>(
cache_simulator->miss_ratio_stats().user_miss_ratio()));
// Assert that the third key is not inserted into the cache.
handle = sim_cache->Lookup(std::to_string(third_get.sst_fd_number) + "_" +
third_get.referenced_key);
ASSERT_EQ(nullptr, handle);
for (uint32_t i = 100; i < block_id; i++) {
if (i < 110 || i >= 115) {
handle = sim_cache->Lookup(kBlockKeyPrefix + std::to_string(i));
ASSERT_NE(nullptr, handle) << i;
sim_cache->Release(handle);
} else {
handle = sim_cache->Lookup(kBlockKeyPrefix + std::to_string(i));
ASSERT_EQ(nullptr, handle) << i;
}
}
}
TEST_F(CacheSimulatorTest, HybridRowBlockCacheSimulatorGetTest) {
BlockCacheTraceRecord get = GenerateGetRecord(kGetId);
get.block_size = 1;
get.referenced_data_size = 0;
get.access_timestamp = 0;
get.block_key = "1";
get.get_id = 1;
get.get_from_user_specified_snapshot = Boolean::kFalse;
get.referenced_key =
kRefKeyPrefix + std::to_string(1) + kRefKeySequenceNumber;
get.no_insert = Boolean::kFalse;
get.sst_fd_number = 0;
get.get_from_user_specified_snapshot = Boolean::kFalse;
std::shared_ptr<Cache> sim_cache =
NewLRUCache(/*capacity=*/16, /*num_shard_bits=*/1,
/*strict_capacity_limit=*/false,
/*high_pri_pool_ratio=*/0);
std::unique_ptr<HybridRowBlockCacheSimulator> cache_simulator(
new HybridRowBlockCacheSimulator(
nullptr, sim_cache, /*insert_blocks_row_kvpair_misses=*/true));
// Expect a miss and does not insert the row key-value pair since it does not
// have size.
cache_simulator->Access(get);
AssertCache(sim_cache, cache_simulator->miss_ratio_stats(), 1, 1, 1, {"1"},
{});
get.access_timestamp += 1;
get.referenced_data_size = 1;
get.block_key = "2";
cache_simulator->Access(get);
AssertCache(sim_cache, cache_simulator->miss_ratio_stats(), 3, 2, 2,
{"1", "2"}, {"1"});
get.access_timestamp += 1;
get.block_key = "3";
// K1 should not inserted again.
cache_simulator->Access(get);
AssertCache(sim_cache, cache_simulator->miss_ratio_stats(), 4, 3, 3,
{"1", "2", "3"}, {"1"});
// A second get request referencing the same key.
get.access_timestamp += 1;
get.get_id = 2;
get.block_key = "4";
get.referenced_data_size = 0;
cache_simulator->Access(get);
AssertCache(sim_cache, cache_simulator->miss_ratio_stats(), 4, 4, 3,
{"1", "2", "3"}, {"1"});
// A third get request searches three files, three different keys.
// And the second key observes a hit.
get.access_timestamp += 1;
get.referenced_data_size = 1;
get.get_id = 3;
get.block_key = "3";
get.referenced_key = kRefKeyPrefix + "2" + kRefKeySequenceNumber;
// K2 should observe a miss. Block 3 observes a hit.
cache_simulator->Access(get);
AssertCache(sim_cache, cache_simulator->miss_ratio_stats(), 5, 5, 3,
{"1", "2", "3"}, {"1", "2"});
get.access_timestamp += 1;
get.referenced_data_size = 1;
get.get_id = 3;
get.block_key = "4";
get.referenced_data_size = 1;
get.referenced_key = kRefKeyPrefix + "1" + kRefKeySequenceNumber;
// K1 should observe a hit.
cache_simulator->Access(get);
AssertCache(sim_cache, cache_simulator->miss_ratio_stats(), 5, 6, 3,
{"1", "2", "3"}, {"1", "2"});
get.access_timestamp += 1;
get.referenced_data_size = 1;
get.get_id = 3;
get.block_key = "4";
get.referenced_data_size = 1;
get.referenced_key = kRefKeyPrefix + "3" + kRefKeySequenceNumber;
// K3 should observe a miss.
// However, as the get already complete, we should not access k3 any more.
cache_simulator->Access(get);
AssertCache(sim_cache, cache_simulator->miss_ratio_stats(), 5, 7, 3,
{"1", "2", "3"}, {"1", "2"});
// A fourth get request searches one file and two blocks. One row key.
get.access_timestamp += 1;
get.get_id = 4;
get.block_key = "5";
get.referenced_key = kRefKeyPrefix + "4" + kRefKeySequenceNumber;
get.referenced_data_size = 1;
cache_simulator->Access(get);
AssertCache(sim_cache, cache_simulator->miss_ratio_stats(), 7, 8, 4,
{"1", "2", "3", "5"}, {"1", "2", "4"});
for (auto const& key : {"1", "2", "4"}) {
auto handle = sim_cache->Lookup("0_" + kRefKeyPrefix + key);
ASSERT_NE(nullptr, handle);
sim_cache->Release(handle);
}
// A bunch of insertions which evict cached row keys.
for (uint32_t i = 6; i < 100; i++) {
get.access_timestamp += 1;
get.get_id = 0;
get.block_key = std::to_string(i);
cache_simulator->Access(get);
}
get.get_id = 4;
// A different block.
get.block_key = "100";
// Same row key and should not be inserted again.
get.referenced_key = kRefKeyPrefix + "4" + kRefKeySequenceNumber;
get.referenced_data_size = 1;
cache_simulator->Access(get);
AssertCache(sim_cache, cache_simulator->miss_ratio_stats(), 16, 103, 99, {},
{});
for (auto const& key : {"1", "2", "4"}) {
auto handle = sim_cache->Lookup("0_" + kRefKeyPrefix + key);
ASSERT_EQ(nullptr, handle);
}
}
TEST_F(CacheSimulatorTest, HybridRowBlockNoInsertCacheSimulator) {
uint64_t block_id = 100;
BlockCacheTraceRecord first_get = GenerateGetRecord(kGetId);
std::shared_ptr<Cache> sim_cache =
NewLRUCache(/*capacity=*/kCacheSize, /*num_shard_bits=*/1,
/*strict_capacity_limit=*/false,
/*high_pri_pool_ratio=*/0);
std::unique_ptr<HybridRowBlockCacheSimulator> cache_simulator(
new HybridRowBlockCacheSimulator(
nullptr, sim_cache, /*insert_blocks_row_kvpair_misses=*/false));
for (uint32_t i = 0; i < 9; i++) {
first_get.block_key = kBlockKeyPrefix + std::to_string(block_id);
cache_simulator->Access(first_get);
block_id++;
}
auto handle =
sim_cache->Lookup(std::to_string(first_get.sst_fd_number) + "_" +
ExtractUserKey(first_get.referenced_key).ToString());
ASSERT_NE(nullptr, handle);
sim_cache->Release(handle);
// All blocks are missing from the cache since insert_blocks_row_kvpair_misses
// is set to false.
for (uint32_t i = 100; i < block_id; i++) {
handle = sim_cache->Lookup(kBlockKeyPrefix + std::to_string(i));
ASSERT_EQ(nullptr, handle);
}
}
TEST_F(CacheSimulatorTest, GhostHybridRowBlockCacheSimulator) {
std::unique_ptr<GhostCache> ghost_cache(new GhostCache(
NewLRUCache(/*capacity=*/kGhostCacheSize, /*num_shard_bits=*/1,
/*strict_capacity_limit=*/false,
/*high_pri_pool_ratio=*/0)));
const BlockCacheTraceRecord& first_get = GenerateGetRecord(kGetId);
const BlockCacheTraceRecord& second_get = GenerateGetRecord(kGetId + 1);
const BlockCacheTraceRecord& third_get = GenerateGetRecord(kGetId + 2);
std::unique_ptr<HybridRowBlockCacheSimulator> cache_simulator(
new HybridRowBlockCacheSimulator(
std::move(ghost_cache),
NewLRUCache(/*capacity=*/kCacheSize, /*num_shard_bits=*/1,
/*strict_capacity_limit=*/false,
/*high_pri_pool_ratio=*/0),
/*insert_blocks_row_kvpair_misses=*/false));
// Two get requests access the same key.
cache_simulator->Access(first_get);
cache_simulator->Access(second_get);
ASSERT_EQ(2, cache_simulator->miss_ratio_stats().total_accesses());
ASSERT_EQ(100, cache_simulator->miss_ratio_stats().miss_ratio());
ASSERT_EQ(2, cache_simulator->miss_ratio_stats().user_accesses());
ASSERT_EQ(100, cache_simulator->miss_ratio_stats().user_miss_ratio());
// We insert the key-value pair upon the second get request. A third get
// request should observe a hit.
for (uint32_t i = 0; i < 10; i++) {
cache_simulator->Access(third_get);
}
ASSERT_EQ(12, cache_simulator->miss_ratio_stats().total_accesses());
ASSERT_EQ(16, static_cast<uint64_t>(
cache_simulator->miss_ratio_stats().miss_ratio()));
ASSERT_EQ(12, cache_simulator->miss_ratio_stats().user_accesses());
ASSERT_EQ(16, static_cast<uint64_t>(
cache_simulator->miss_ratio_stats().user_miss_ratio()));
}
} // namespace rocksdb
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
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