Commit Graph

16 Commits

Author SHA1 Message Date
haoyuhuang
8a008d4170 Block access tracing: Trace referenced key for Get on non-data blocks. (#5548)
Summary:
This PR traces the referenced key for Get for all types of blocks. This is useful when evaluating hybrid row-block caches.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5548

Test Plan: make clean && USE_CLANG=1 make check -j32

Differential Revision: D16157979

Pulled By: HaoyuHuang

fbshipit-source-id: f6327411c9deb74e35e22a35f66cdbae09ab9d87
2019-07-17 13:05:58 -07:00
haoyuhuang
3e9c5a3523 Block cache analyzer: Add more stats (#5516)
Summary:
This PR provides more command line options for block cache analyzer to better understand block cache access pattern.
-analyze_bottom_k_access_count_blocks
-analyze_top_k_access_count_blocks
-reuse_lifetime_labels
-reuse_lifetime_buckets
-analyze_callers
-access_count_buckets
-analyze_blocks_reuse_k_reuse_window
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5516

Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32

Differential Revision: D16037440

Pulled By: HaoyuHuang

fbshipit-source-id: b9a4ac0d4712053fab910732077a4d4b91400bc8
2019-07-12 16:55:34 -07:00
haoyuhuang
1a59b6e2a9 Cache simulator: Add a ghost cache for admission control and a hybrid row-block cache. (#5534)
Summary:
This PR adds a ghost cache for admission control. Specifically, it admits an entry on its second access.
It also adds a hybrid row-block cache that caches the referenced key-value pairs of a Get/MultiGet request instead of its blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5534

Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32

Differential Revision: D16101124

Pulled By: HaoyuHuang

fbshipit-source-id: b99edda6418a888e94eb40f71ece45d375e234b1
2019-07-11 12:43:29 -07:00
haoyuhuang
6edc5d0719 Block cache tracing: Associate a unique id with Get and MultiGet (#5514)
Summary:
This PR associates a unique id with Get and MultiGet. This enables us to track how many blocks a Get/MultiGet request accesses. We can also measure the impact of row cache vs block cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5514

Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32

Differential Revision: D16032681

Pulled By: HaoyuHuang

fbshipit-source-id: 775b05f4440badd58de6667e3ec9f4fc87a0af4c
2019-07-03 19:35:41 -07:00
haoyuhuang
66464d1fde Remove multiple declarations o kMicrosInSecond.
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5526

Test Plan:
OPT=-g V=1 make J=1 unity_test -j32
make clean && make -j32

Differential Revision: D16079315

Pulled By: HaoyuHuang

fbshipit-source-id: 294ab439cf0db8dd5da44e30eabf0cbb2bb8c4f6
2019-07-01 15:15:12 -07:00
haoyuhuang
68b46a2e36 Block cache tracer: StartTrace return busy if trace is already started. (#5519)
Summary:
This PR is needed for integration into MyRocks. A second call on StartTrace returns Busy so that MyRocks may return an error to the user.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5519

Test Plan: make clean && USE_CLANG=1 make check -j32

Differential Revision: D16055476

Pulled By: HaoyuHuang

fbshipit-source-id: a51772fb0965c873922757eb470a332b1e02a91d
2019-06-30 20:03:01 -07:00
haoyuhuang
a8975b6245 Block cache tracer: Do not populate block cache trace record when tracing is disabled. (#5510)
Summary:
This PR makes sure that trace record is not populated when tracing is disabled.

Before this PR:
DB path: [/data/mysql/rocks_regression_tests/OPTIONS-myrocks-40-33-10000000/2019-06-26-13-04-41/db]
readwhilewriting :       9.803 micros/op 1550408 ops/sec;  107.9 MB/s (5000000 of 5000000 found)
Microseconds per read:
Count: 80000000 Average: 9.8045  StdDev: 12.64
Min: 1  Median: 7.5246  Max: 25343
Percentiles: P50: 7.52 P75: 12.10 P99: 37.44 P99.9: 75.07 P99.99: 133.60

After this PR:
DB path: [/data/mysql/rocks_regression_tests/OPTIONS-myrocks-40-33-10000000/2019-06-26-14-08-21/db]
readwhilewriting :       8.723 micros/op 1662882 ops/sec;  115.8 MB/s (5000000 of 5000000 found)
Microseconds per read:
Count: 80000000 Average: 8.7236  StdDev: 12.19
Min: 1  Median: 6.7262  Max: 25229
Percentiles: P50: 6.73 P75: 10.50 P99: 31.54 P99.9: 74.81 P99.99: 132.82
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5510

Differential Revision: D16016428

Pulled By: HaoyuHuang

fbshipit-source-id: 3b3d11e6accf207d18ec2545b802aa01ee65901f
2019-06-27 08:34:08 -07:00
haoyuhuang
705b8eecb4 Add more callers for table reader. (#5454)
Summary:
This PR adds more callers for table readers. These information are only used for block cache analysis so that we can know which caller accesses a block.
1. It renames the BlockCacheLookupCaller to TableReaderCaller as passing the caller from upstream requires changes to table_reader.h and TableReaderCaller is a more appropriate name.
2. It adds more table reader callers in table/table_reader_caller.h, e.g., kCompactionRefill, kExternalSSTIngestion, and kBuildTable.

This PR is long as it requires modification of interfaces in table_reader.h, e.g., NewIterator.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5454

Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32.

Differential Revision: D15819451

Pulled By: HaoyuHuang

fbshipit-source-id: b6caa704c8fb96ddd15b9a934b7e7ea87f88092d
2019-06-20 14:31:48 -07:00
haoyuhuang
bcfc53b436 Block cache tracing: Fix minor bugs with downsampling and some benchmark results. (#5473)
Summary:
As the code changes for block cache tracing are almost complete, I did a benchmark to compare the performance when block cache tracing is enabled/disabled.

 With 1% downsampling ratio, the performance overhead of block cache tracing is negligible. When we trace all block accesses, the throughput drops by 6 folds with 16 threads issuing random reads and all reads are served in block cache.

Setup:
RocksDB:    version 6.2
Date:       Mon Jun 17 17:11:13 2019
CPU:        24 * Intel Core Processor (Skylake)
CPUCache:   16384 KB
Keys:       20 bytes each
Values:     100 bytes each (100 bytes after compression)
Entries:    10000000
Prefix:    20 bytes
Keys per prefix:    0
RawSize:    1144.4 MB (estimated)
FileSize:   1144.4 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: NoCompression
Compression sampling rate: 0
Memtablerep: skip_list
Perf Level: 1

I ran the readrandom workload for 1 minute. Detailed throughput results:  (ops/second)
Sample rate 0: no block cache tracing.
Sample rate 1: trace all block accesses.
Sample rate 100: trace accesses 1% blocks.
1 thread |   |   |  -- | -- | -- | --
Sample rate | 0 | 1 | 100
1 MB block cache size | 13,094 | 13,166 | 13,341
10 GB block cache size | 202,243 | 188,677 | 229,182

16 threads |   |   |  -- | -- | -- | --
Sample rate | 0 | 1 | 100
1 MB block cache size | 208,761 | 178,700 | 201,872
10 GB block cache size | 2,645,996 | 426,295 | 2,587,605
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5473

Differential Revision: D15869479

Pulled By: HaoyuHuang

fbshipit-source-id: 7ae802abe84811281a6af8649f489887cd7c4618
2019-06-17 17:59:02 -07:00
haoyuhuang
7a8d7358bb Integrate block cache tracer in block based table reader. (#5441)
Summary:
This PR integrates the block cache tracer into block based table reader. The tracer will write the block cache accesses using the trace_writer. The tracer is null in this PR so that nothing will be logged.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5441

Differential Revision: D15772029

Pulled By: HaoyuHuang

fbshipit-source-id: a64adb92642cd23222e0ba8b10d86bf522b42f9b
2019-06-14 17:40:31 -07:00
haoyuhuang
89695bfbaa Remove unused variable (#5457)
Summary:
This PR removes the unused variable that causes CLANG build to fail.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5457

Differential Revision: D15825027

Pulled By: HaoyuHuang

fbshipit-source-id: 72c847c39ca310560efcbc5938cffa6f31164068
2019-06-14 09:17:09 -07:00
haoyuhuang
bb4178066d Integrate block cache tracer into db_impl (#5433)
Summary:
This PR integrates the block cache tracer class into db_impl.cc.
db_impl.cc contains a member variable of AtomicBlockCacheTraceWriter class and passes its reference to the block_based_table_reader.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5433

Differential Revision: D15728016

Pulled By: HaoyuHuang

fbshipit-source-id: 23d5659e8c82d556833dcc1a5558aac8c1f7db71
2019-06-13 15:43:10 -07:00
haoyuhuang
9bbccda01e First commit for block cache trace analyzer (#5425)
Summary:
This PR contains the first commit for block cache trace analyzer. It reads a block cache trace file and prints statistics of the traces.

We will extend this class to provide more functionalities.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5425

Differential Revision: D15709580

Pulled By: HaoyuHuang

fbshipit-source-id: 2f43bd2311f460ab569880819d95eeae217c20bb
2019-06-11 12:22:44 -07:00
haoyuhuang
5efa0d6b0d Create a BlockCacheLookupContext to enable fine-grained block cache tracing. (#5421)
Summary:
BlockCacheLookupContext only contains the caller for now.
We will trace block accesses at five places:
1. BlockBasedTable::GetFilter.
2. BlockBasedTable::GetUncompressedDict.
3. BlockBasedTable::MaybeReadAndLoadToCache. (To trace access on data, index, and range deletion block.)
4. BlockBasedTable::Get. (To trace the referenced key and whether the referenced key exists in a fetched data block.)
5. BlockBasedTable::MultiGet. (To trace the referenced key and whether the referenced key exists in a fetched data block.)

We create the context at:
1. BlockBasedTable::Get. (kUserGet)
2. BlockBasedTable::MultiGet. (kUserMGet)
3. BlockBasedTable::NewIterator. (either kUserIterator, kCompaction, or external SST ingestion calls this function.)
4. BlockBasedTable::Open. (kPrefetch)
5. Index/Filter::CacheDependencies. (kPrefetch)
6. BlockBasedTable::ApproximateOffsetOf. (kCompaction or kUserApproximateSize).

I loaded 1 million key-value pairs into the database and ran the readrandom benchmark with a single thread. I gave the block cache 10 GB to make sure all reads hit the block cache after warmup. The throughput is comparable.
Throughput of this PR: 231334 ops/s.
Throughput of the master branch: 238428 ops/s.

Experiment setup:
RocksDB:    version 6.2
Date:       Mon Jun 10 10:42:51 2019
CPU:        24 * Intel Core Processor (Skylake)
CPUCache:   16384 KB
Keys:       20 bytes each
Values:     100 bytes each (100 bytes after compression)
Entries:    1000000
Prefix:    20 bytes
Keys per prefix:    0
RawSize:    114.4 MB (estimated)
FileSize:   114.4 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: NoCompression
Compression sampling rate: 0
Memtablerep: skip_list
Perf Level: 1

Load command: ./db_bench --benchmarks="fillseq" --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --statistics --cache_index_and_filter_blocks --cache_size=10737418240 --disable_auto_compactions=1 --disable_wal=1 --compression_type=none --min_level_to_compress=-1 --compression_ratio=1 --num=1000000

Run command: ./db_bench --benchmarks="readrandom,stats" --use_existing_db --threads=1 --duration=120 --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --statistics --cache_index_and_filter_blocks --cache_size=10737418240 --disable_auto_compactions=1 --disable_wal=1 --compression_type=none --min_level_to_compress=-1 --compression_ratio=1 --num=1000000 --duration=120

TODOs:
1. Create a caller for external SST file ingestion and differentiate the callers for iterator.
2. Integrate tracer to trace block cache accesses.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5421

Differential Revision: D15704258

Pulled By: HaoyuHuang

fbshipit-source-id: 4aa8a55f8cb1576ffb367bfa3186a91d8f06d93a
2019-06-10 15:33:27 -07:00
haoyuhuang
aa71718ac3 Add block cache tracer. (#5410)
Summary:
This PR adds a help class block cache tracer to read/write block cache accesses. It uses the trace reader/writer to perform this task.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5410

Differential Revision: D15612843

Pulled By: HaoyuHuang

fbshipit-source-id: f30fd1e1524355ca87db5d533a5c086728b141ea
2019-06-06 11:24:39 -07:00
Siying Dong
5851cb7fdb Move util/trace_replay.* to trace_replay/ (#5376)
Summary:
util/ means for lower level libraries. trace_replay is highly integrated to DB and sometimes call DB. Move it out to a separate directory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5376

Differential Revision: D15550938

Pulled By: siying

fbshipit-source-id: f46dce5ceffdc05a73f26379c7bb1b79ebe6c207
2019-06-03 13:25:26 -07:00