rocksdb/memtable/write_buffer_manager_test.cc
matthewvon 4126bdc0e1 Feature: add SetBufferSize() so that managed size can be dynamic (#7961)
Summary:
This PR adds SetBufferSize() to the WriteBufferManager object.  This enables user code to adjust the global budget for write_buffers based upon other memory conditions such as growth in table reader memory as the dataset grows.

The buffer_size_ member variable is now atomic to match design of other changeable size_t members within WriteBufferManager.

This change is useful as is.  However, this change is also essential if someone decides they wanted to enable db_write_buffer_size modifications through the DB::SetOptions() API, i.e. no waste taking this as is.

Any format / spacing changes are due to clang-format as required by check-in automation.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7961

Reviewed By: ajkr

Differential Revision: D26639075

Pulled By: akankshamahajan15

fbshipit-source-id: 0604348caf092d35f44e85715331dc920e5c1033
2021-03-03 14:22:11 -08:00

231 lines
8.4 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 "rocksdb/write_buffer_manager.h"
#include "test_util/testharness.h"
namespace ROCKSDB_NAMESPACE {
class WriteBufferManagerTest : public testing::Test {};
#ifndef ROCKSDB_LITE
const size_t kSizeDummyEntry = 256 * 1024;
TEST_F(WriteBufferManagerTest, ShouldFlush) {
// A write buffer manager of size 10MB
std::unique_ptr<WriteBufferManager> wbf(
new WriteBufferManager(10 * 1024 * 1024));
wbf->ReserveMem(8 * 1024 * 1024);
ASSERT_FALSE(wbf->ShouldFlush());
// 90% of the hard limit will hit the condition
wbf->ReserveMem(1 * 1024 * 1024);
ASSERT_TRUE(wbf->ShouldFlush());
// Scheduling for freeing will release the condition
wbf->ScheduleFreeMem(1 * 1024 * 1024);
ASSERT_FALSE(wbf->ShouldFlush());
wbf->ReserveMem(2 * 1024 * 1024);
ASSERT_TRUE(wbf->ShouldFlush());
wbf->ScheduleFreeMem(4 * 1024 * 1024);
// 11MB total, 6MB mutable. hard limit still hit
ASSERT_TRUE(wbf->ShouldFlush());
wbf->ScheduleFreeMem(2 * 1024 * 1024);
// 11MB total, 4MB mutable. hard limit stills but won't flush because more
// than half data is already being flushed.
ASSERT_FALSE(wbf->ShouldFlush());
wbf->ReserveMem(4 * 1024 * 1024);
// 15 MB total, 8MB mutable.
ASSERT_TRUE(wbf->ShouldFlush());
wbf->FreeMem(7 * 1024 * 1024);
// 8MB total, 8MB mutable.
ASSERT_FALSE(wbf->ShouldFlush());
// change size: 8M limit, 7M mutable limit
wbf->SetBufferSize(8 * 1024 * 1024);
// 8MB total, 8MB mutable.
ASSERT_TRUE(wbf->ShouldFlush());
wbf->ScheduleFreeMem(2 * 1024 * 1024);
// 8MB total, 6MB mutable.
ASSERT_TRUE(wbf->ShouldFlush());
wbf->FreeMem(2 * 1024 * 1024);
// 6MB total, 6MB mutable.
ASSERT_FALSE(wbf->ShouldFlush());
wbf->ReserveMem(1 * 1024 * 1024);
// 7MB total, 7MB mutable.
ASSERT_FALSE(wbf->ShouldFlush());
wbf->ReserveMem(1 * 1024 * 1024);
// 8MB total, 8MB mutable.
ASSERT_TRUE(wbf->ShouldFlush());
wbf->ScheduleFreeMem(1 * 1024 * 1024);
wbf->FreeMem(1 * 1024 * 1024);
// 7MB total, 7MB mutable.
ASSERT_FALSE(wbf->ShouldFlush());
}
TEST_F(WriteBufferManagerTest, CacheCost) {
LRUCacheOptions co;
// 1GB cache
co.capacity = 1024 * 1024 * 1024;
co.num_shard_bits = 4;
co.metadata_charge_policy = kDontChargeCacheMetadata;
std::shared_ptr<Cache> cache = NewLRUCache(co);
// A write buffer manager of size 50MB
std::unique_ptr<WriteBufferManager> wbf(
new WriteBufferManager(50 * 1024 * 1024, cache));
// Allocate 333KB will allocate 512KB
wbf->ReserveMem(333 * 1024);
ASSERT_GE(cache->GetPinnedUsage(), 2 * 256 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 2 * 256 * 1024 + 10000);
// 2 dummy entries are added for size 333 kb.
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 2 * kSizeDummyEntry);
// Allocate another 512KB
wbf->ReserveMem(512 * 1024);
ASSERT_GE(cache->GetPinnedUsage(), 4 * 256 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 4 * 256 * 1024 + 10000);
// 2 more dummy entries are added for size 512.
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 4 * kSizeDummyEntry);
// Allocate another 10MB
wbf->ReserveMem(10 * 1024 * 1024);
ASSERT_GE(cache->GetPinnedUsage(), 11 * 1024 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 11 * 1024 * 1024 + 10000);
// 40 more entries are added for size 10 * 1024 * 1024.
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 44 * kSizeDummyEntry);
// Free 1MB will not cause any change in cache cost
wbf->FreeMem(1024 * 1024);
ASSERT_GE(cache->GetPinnedUsage(), 11 * 1024 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 11 * 1024 * 1024 + 10000);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 44 * kSizeDummyEntry);
ASSERT_FALSE(wbf->ShouldFlush());
// Allocate another 41MB
wbf->ReserveMem(41 * 1024 * 1024);
ASSERT_GE(cache->GetPinnedUsage(), 51 * 1024 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 51 * 1024 * 1024 + 10000);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 204 * kSizeDummyEntry);
ASSERT_TRUE(wbf->ShouldFlush());
ASSERT_TRUE(wbf->ShouldFlush());
wbf->ScheduleFreeMem(20 * 1024 * 1024);
ASSERT_GE(cache->GetPinnedUsage(), 51 * 1024 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 51 * 1024 * 1024 + 10000);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 204 * kSizeDummyEntry);
// Still need flush as the hard limit hits
ASSERT_TRUE(wbf->ShouldFlush());
// Free 20MB will releae 256KB from cache
wbf->FreeMem(20 * 1024 * 1024);
ASSERT_GE(cache->GetPinnedUsage(), 51 * 1024 * 1024 - 256 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 51 * 1024 * 1024 - 256 * 1024 + 10000);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 203 * kSizeDummyEntry);
ASSERT_FALSE(wbf->ShouldFlush());
// Every free will release 256KB if still not hit 3/4
wbf->FreeMem(16 * 1024);
ASSERT_GE(cache->GetPinnedUsage(), 51 * 1024 * 1024 - 2 * 256 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 51 * 1024 * 1024 - 2 * 256 * 1024 + 10000);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 202 * kSizeDummyEntry);
wbf->FreeMem(16 * 1024);
ASSERT_GE(cache->GetPinnedUsage(), 51 * 1024 * 1024 - 3 * 256 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 51 * 1024 * 1024 - 3 * 256 * 1024 + 10000);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 201 * kSizeDummyEntry);
// Reserve 512KB will not cause any change in cache cost
wbf->ReserveMem(512 * 1024);
ASSERT_GE(cache->GetPinnedUsage(), 51 * 1024 * 1024 - 3 * 256 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 51 * 1024 * 1024 - 3 * 256 * 1024 + 10000);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 201 * kSizeDummyEntry);
wbf->FreeMem(16 * 1024);
ASSERT_GE(cache->GetPinnedUsage(), 51 * 1024 * 1024 - 4 * 256 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 51 * 1024 * 1024 - 4 * 256 * 1024 + 10000);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 200 * kSizeDummyEntry);
// Destory write buffer manger should free everything
wbf.reset();
ASSERT_LT(cache->GetPinnedUsage(), 1024 * 1024);
}
TEST_F(WriteBufferManagerTest, NoCapCacheCost) {
// 1GB cache
std::shared_ptr<Cache> cache = NewLRUCache(1024 * 1024 * 1024, 4);
// A write buffer manager of size 256MB
std::unique_ptr<WriteBufferManager> wbf(new WriteBufferManager(0, cache));
// Allocate 1.5MB will allocate 2MB
wbf->ReserveMem(10 * 1024 * 1024);
ASSERT_GE(cache->GetPinnedUsage(), 10 * 1024 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 10 * 1024 * 1024 + 10000);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 40 * kSizeDummyEntry);
ASSERT_FALSE(wbf->ShouldFlush());
wbf->FreeMem(9 * 1024 * 1024);
for (int i = 0; i < 40; i++) {
wbf->FreeMem(4 * 1024);
}
ASSERT_GE(cache->GetPinnedUsage(), 1024 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 1024 * 1024 + 10000);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 4 * kSizeDummyEntry);
}
TEST_F(WriteBufferManagerTest, CacheFull) {
// 15MB cache size with strict capacity
LRUCacheOptions lo;
lo.capacity = 12 * 1024 * 1024;
lo.num_shard_bits = 0;
lo.strict_capacity_limit = true;
std::shared_ptr<Cache> cache = NewLRUCache(lo);
std::unique_ptr<WriteBufferManager> wbf(new WriteBufferManager(0, cache));
wbf->ReserveMem(10 * 1024 * 1024);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 40 * kSizeDummyEntry);
size_t prev_pinned = cache->GetPinnedUsage();
ASSERT_GE(prev_pinned, 10 * 1024 * 1024);
// Some insert will fail
wbf->ReserveMem(10 * 1024 * 1024);
ASSERT_LE(cache->GetPinnedUsage(), 12 * 1024 * 1024);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 80 * kSizeDummyEntry);
// Increase capacity so next insert will succeed
cache->SetCapacity(30 * 1024 * 1024);
wbf->ReserveMem(10 * 1024 * 1024);
ASSERT_GT(cache->GetPinnedUsage(), 20 * 1024 * 1024);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 120 * kSizeDummyEntry);
// Gradually release 20 MB
for (int i = 0; i < 40; i++) {
wbf->FreeMem(512 * 1024);
}
ASSERT_GE(cache->GetPinnedUsage(), 10 * 1024 * 1024);
ASSERT_LT(cache->GetPinnedUsage(), 20 * 1024 * 1024);
ASSERT_EQ(wbf->dummy_entries_in_cache_usage(), 95 * kSizeDummyEntry);
}
#endif // ROCKSDB_LITE
} // namespace ROCKSDB_NAMESPACE
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}