rocksdb/utilities/util_merge_operators_test.cc
Islam AbdelRahman 68a8e6b8fa Introduce FullMergeV2 (eliminate memcpy from merge operators)
Summary:
This diff update the code to pin the merge operator operands while the merge operation is done, so that we can eliminate the memcpy cost, to do that we need a new public API for FullMerge that replace the std::deque<std::string> with std::vector<Slice>

This diff is stacked on top of D56493 and D56511

In this diff we
- Update FullMergeV2 arguments to be encapsulated in MergeOperationInput and MergeOperationOutput which will make it easier to add new arguments in the future
- Replace std::deque<std::string> with std::vector<Slice> to pass operands
- Replace MergeContext std::deque with std::vector (based on a simple benchmark I ran https://gist.github.com/IslamAbdelRahman/78fc86c9ab9f52b1df791e58943fb187)
- Allow FullMergeV2 output to be an existing operand

```
[Everything in Memtable | 10K operands | 10 KB each | 1 operand per key]

DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="mergerandom,readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --merge_keys=10000 --num=10000 --disable_auto_compactions --value_size=10240 --write_buffer_size=1000000000

[FullMergeV2]
readseq      :       0.607 micros/op 1648235 ops/sec; 16121.2 MB/s
readseq      :       0.478 micros/op 2091546 ops/sec; 20457.2 MB/s
readseq      :       0.252 micros/op 3972081 ops/sec; 38850.5 MB/s
readseq      :       0.237 micros/op 4218328 ops/sec; 41259.0 MB/s
readseq      :       0.247 micros/op 4043927 ops/sec; 39553.2 MB/s

[master]
readseq      :       3.935 micros/op 254140 ops/sec; 2485.7 MB/s
readseq      :       3.722 micros/op 268657 ops/sec; 2627.7 MB/s
readseq      :       3.149 micros/op 317605 ops/sec; 3106.5 MB/s
readseq      :       3.125 micros/op 320024 ops/sec; 3130.1 MB/s
readseq      :       4.075 micros/op 245374 ops/sec; 2400.0 MB/s
```

```
[Everything in Memtable | 10K operands | 10 KB each | 10 operand per key]

DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="mergerandom,readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --merge_keys=1000 --num=10000 --disable_auto_compactions --value_size=10240 --write_buffer_size=1000000000

[FullMergeV2]
readseq      :       3.472 micros/op 288018 ops/sec; 2817.1 MB/s
readseq      :       2.304 micros/op 434027 ops/sec; 4245.2 MB/s
readseq      :       1.163 micros/op 859845 ops/sec; 8410.0 MB/s
readseq      :       1.192 micros/op 838926 ops/sec; 8205.4 MB/s
readseq      :       1.250 micros/op 800000 ops/sec; 7824.7 MB/s

[master]
readseq      :      24.025 micros/op 41623 ops/sec;  407.1 MB/s
readseq      :      18.489 micros/op 54086 ops/sec;  529.0 MB/s
readseq      :      18.693 micros/op 53495 ops/sec;  523.2 MB/s
readseq      :      23.621 micros/op 42335 ops/sec;  414.1 MB/s
readseq      :      18.775 micros/op 53262 ops/sec;  521.0 MB/s

```

```
[Everything in Block cache | 10K operands | 10 KB each | 1 operand per key]

[FullMergeV2]
$ DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --num=100000 --db="/dev/shm/merge-random-10K-10KB" --cache_size=1000000000 --use_existing_db --disable_auto_compactions
readseq      :      14.741 micros/op 67837 ops/sec;  663.5 MB/s
readseq      :       1.029 micros/op 971446 ops/sec; 9501.6 MB/s
readseq      :       0.974 micros/op 1026229 ops/sec; 10037.4 MB/s
readseq      :       0.965 micros/op 1036080 ops/sec; 10133.8 MB/s
readseq      :       0.943 micros/op 1060657 ops/sec; 10374.2 MB/s

[master]
readseq      :      16.735 micros/op 59755 ops/sec;  584.5 MB/s
readseq      :       3.029 micros/op 330151 ops/sec; 3229.2 MB/s
readseq      :       3.136 micros/op 318883 ops/sec; 3119.0 MB/s
readseq      :       3.065 micros/op 326245 ops/sec; 3191.0 MB/s
readseq      :       3.014 micros/op 331813 ops/sec; 3245.4 MB/s
```

```
[Everything in Block cache | 10K operands | 10 KB each | 10 operand per key]

DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --num=100000 --db="/dev/shm/merge-random-10-operands-10K-10KB" --cache_size=1000000000 --use_existing_db --disable_auto_compactions

[FullMergeV2]
readseq      :      24.325 micros/op 41109 ops/sec;  402.1 MB/s
readseq      :       1.470 micros/op 680272 ops/sec; 6653.7 MB/s
readseq      :       1.231 micros/op 812347 ops/sec; 7945.5 MB/s
readseq      :       1.091 micros/op 916590 ops/sec; 8965.1 MB/s
readseq      :       1.109 micros/op 901713 ops/sec; 8819.6 MB/s

[master]
readseq      :      27.257 micros/op 36687 ops/sec;  358.8 MB/s
readseq      :       4.443 micros/op 225073 ops/sec; 2201.4 MB/s
readseq      :       5.830 micros/op 171526 ops/sec; 1677.7 MB/s
readseq      :       4.173 micros/op 239635 ops/sec; 2343.8 MB/s
readseq      :       4.150 micros/op 240963 ops/sec; 2356.8 MB/s
```

Test Plan: COMPILE_WITH_ASAN=1 make check -j64

Reviewers: yhchiang, andrewkr, sdong

Reviewed By: sdong

Subscribers: lovro, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57075
2016-07-20 09:49:03 -07:00

100 lines
3.3 KiB
C++

// Copyright (c) 2011-present, 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 "util/testharness.h"
#include "util/testutil.h"
#include "utilities/merge_operators.h"
namespace rocksdb {
class UtilMergeOperatorTest : public testing::Test {
public:
UtilMergeOperatorTest() {}
std::string FullMergeV2(std::string existing_value,
std::vector<std::string> operands,
std::string key = "") {
std::string result;
Slice result_operand(nullptr, 0);
Slice existing_value_slice(existing_value);
std::vector<Slice> operands_slice(operands.begin(), operands.end());
const MergeOperator::MergeOperationInput merge_in(
key, &existing_value_slice, operands_slice, nullptr);
MergeOperator::MergeOperationOutput merge_out(result, result_operand);
merge_operator_->FullMergeV2(merge_in, &merge_out);
if (result_operand.data()) {
result.assign(result_operand.data(), result_operand.size());
}
return result;
}
std::string FullMergeV2(std::vector<std::string> operands,
std::string key = "") {
std::string result;
Slice result_operand(nullptr, 0);
std::vector<Slice> operands_slice(operands.begin(), operands.end());
const MergeOperator::MergeOperationInput merge_in(key, nullptr,
operands_slice, nullptr);
MergeOperator::MergeOperationOutput merge_out(result, result_operand);
merge_operator_->FullMergeV2(merge_in, &merge_out);
if (result_operand.data()) {
result.assign(result_operand.data(), result_operand.size());
}
return result;
}
std::string PartialMerge(std::string left, std::string right,
std::string key = "") {
std::string result;
merge_operator_->PartialMerge(key, left, right, &result, nullptr);
return result;
}
std::string PartialMergeMulti(std::deque<std::string> operands,
std::string key = "") {
std::string result;
std::deque<Slice> operands_slice(operands.begin(), operands.end());
merge_operator_->PartialMergeMulti(key, operands_slice, &result, nullptr);
return result;
}
protected:
std::shared_ptr<MergeOperator> merge_operator_;
};
TEST_F(UtilMergeOperatorTest, MaxMergeOperator) {
merge_operator_ = MergeOperators::CreateMaxOperator();
EXPECT_EQ("B", FullMergeV2("B", {"A"}));
EXPECT_EQ("B", FullMergeV2("A", {"B"}));
EXPECT_EQ("", FullMergeV2({"", "", ""}));
EXPECT_EQ("A", FullMergeV2({"A"}));
EXPECT_EQ("ABC", FullMergeV2({"ABC"}));
EXPECT_EQ("Z", FullMergeV2({"ABC", "Z", "C", "AXX"}));
EXPECT_EQ("ZZZ", FullMergeV2({"ABC", "CC", "Z", "ZZZ"}));
EXPECT_EQ("a", FullMergeV2("a", {"ABC", "CC", "Z", "ZZZ"}));
EXPECT_EQ("z", PartialMergeMulti({"a", "z", "efqfqwgwew", "aaz", "hhhhh"}));
EXPECT_EQ("b", PartialMerge("a", "b"));
EXPECT_EQ("z", PartialMerge("z", "azzz"));
EXPECT_EQ("a", PartialMerge("a", ""));
}
} // namespace rocksdb
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}