rocksdb/db/write_controller_test.cc
sdong b9f77ba12b When slowdown is triggered, reduce the write rate
Summary: It's usually hard for users to set a value of options.delayed_write_rate. With this diff, after slowdown condition triggers, we greedily reduce write rate if estimated pending compaction bytes increase. If estimated compaction pending bytes drop, we increase the write rate.

Test Plan:
Add a unit test
Test with db_bench setting:
TEST_TMPDIR=/dev/shm/ ./db_bench --benchmarks=fillrandom -num=10000000 --soft_pending_compaction_bytes_limit=1000000000 --hard_pending_compaction_bytes_limit=3000000000 --delayed_write_rate=100000000

and make sure without the commit, write stop will happen, but with the commit, it will not happen.

Reviewers: igor, anthony, rven, yhchiang, kradhakrishnan, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D52131
2015-12-23 11:33:15 -08:00

132 lines
4.5 KiB
C++

// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
//
#include "db/write_controller.h"
#include "rocksdb/env.h"
#include "util/testharness.h"
namespace rocksdb {
class WriteControllerTest : public testing::Test {};
class TimeSetEnv : public EnvWrapper {
public:
explicit TimeSetEnv() : EnvWrapper(nullptr) {}
uint64_t now_micros_ = 6666;
virtual uint64_t NowMicros() override { return now_micros_; }
};
TEST_F(WriteControllerTest, ChangeDelayRateTest) {
TimeSetEnv env;
WriteController controller(10000000u);
auto delay_token_0 =
controller.GetDelayToken(controller.delayed_write_rate());
ASSERT_EQ(static_cast<uint64_t>(2000000),
controller.GetDelay(&env, 20000000u));
auto delay_token_1 = controller.GetDelayToken(2000000u);
ASSERT_EQ(static_cast<uint64_t>(10000000),
controller.GetDelay(&env, 20000000u));
auto delay_token_2 = controller.GetDelayToken(1000000u);
ASSERT_EQ(static_cast<uint64_t>(20000000),
controller.GetDelay(&env, 20000000u));
auto delay_token_3 = controller.GetDelayToken(20000000u);
ASSERT_EQ(static_cast<uint64_t>(1000000),
controller.GetDelay(&env, 20000000u));
auto delay_token_4 =
controller.GetDelayToken(controller.delayed_write_rate() * 2);
ASSERT_EQ(static_cast<uint64_t>(500000),
controller.GetDelay(&env, 20000000u));
}
TEST_F(WriteControllerTest, SanityTest) {
WriteController controller(10000000u);
auto stop_token_1 = controller.GetStopToken();
auto stop_token_2 = controller.GetStopToken();
ASSERT_TRUE(controller.IsStopped());
stop_token_1.reset();
ASSERT_TRUE(controller.IsStopped());
stop_token_2.reset();
ASSERT_FALSE(controller.IsStopped());
TimeSetEnv env;
auto delay_token_1 = controller.GetDelayToken(10000000u);
ASSERT_EQ(static_cast<uint64_t>(2000000),
controller.GetDelay(&env, 20000000u));
env.now_micros_ += 1999900u; // sleep debt 1000
auto delay_token_2 = controller.GetDelayToken(10000000u);
// Rate reset after changing the token.
ASSERT_EQ(static_cast<uint64_t>(2000000),
controller.GetDelay(&env, 20000000u));
env.now_micros_ += 1999900u; // sleep debt 1000
// One refill: 10240 bytes allowed, 1000 used, 9240 left
ASSERT_EQ(static_cast<uint64_t>(1124), controller.GetDelay(&env, 1000u));
env.now_micros_ += 1124u; // sleep debt 0
delay_token_2.reset();
// 1000 used, 8240 left
ASSERT_EQ(static_cast<uint64_t>(0), controller.GetDelay(&env, 1000u));
env.now_micros_ += 100u; // sleep credit 100
// 1000 used, 7240 left
ASSERT_EQ(static_cast<uint64_t>(0), controller.GetDelay(&env, 1000u));
env.now_micros_ += 100u; // sleep credit 200
// One refill: 10240 fileed, sleep credit generates 2000. 8000 used
// 7240 + 10240 + 2000 - 8000 = 11480 left
ASSERT_EQ(static_cast<uint64_t>(1024u), controller.GetDelay(&env, 8000u));
env.now_micros_ += 200u; // sleep debt 824
// 1000 used, 10480 left.
ASSERT_EQ(static_cast<uint64_t>(0), controller.GetDelay(&env, 1000u));
env.now_micros_ += 200u; // sleep debt 624
// Out of bound sleep, still 10480 left
ASSERT_EQ(static_cast<uint64_t>(3000624u),
controller.GetDelay(&env, 30000000u));
env.now_micros_ += 3000724u; // sleep credit 100
// 6000 used, 4480 left.
ASSERT_EQ(static_cast<uint64_t>(0), controller.GetDelay(&env, 6000u));
env.now_micros_ += 200u; // sleep credit 300
// One refill, credit 4480 balance + 3000 credit + 10240 refill
// Use 8000, 9720 left
ASSERT_EQ(static_cast<uint64_t>(1024u), controller.GetDelay(&env, 8000u));
env.now_micros_ += 3024u; // sleep credit 2000
// 1720 left
ASSERT_EQ(static_cast<uint64_t>(0u), controller.GetDelay(&env, 8000u));
// 1720 balance + 20000 credit = 20170 left
// Use 8000, 12170 left
ASSERT_EQ(static_cast<uint64_t>(0u), controller.GetDelay(&env, 8000u));
// 4170 left
ASSERT_EQ(static_cast<uint64_t>(0u), controller.GetDelay(&env, 8000u));
// Need a refill
ASSERT_EQ(static_cast<uint64_t>(1024u), controller.GetDelay(&env, 9000u));
delay_token_1.reset();
ASSERT_EQ(static_cast<uint64_t>(0), controller.GetDelay(&env, 30000000u));
delay_token_1.reset();
ASSERT_FALSE(controller.IsStopped());
}
} // namespace rocksdb
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}