3 Commits (ddd088c8b91f8f63a110cb3262cc4e4d22fab7ca)

Author	SHA1	Message	Date
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	6 years ago
haoyuhuang	2d1dd5bce7	Support computing miss ratio curves using sim_cache. (#5449) ... Summary: This PR adds a BlockCacheTraceSimulator that reports the miss ratios given different cache configurations. A cache configuration contains "cache_name,num_shard_bits,cache_capacities". For example, "lru, 1, 1K, 2K, 4M, 4G". When we replay the trace, we also perform lookups and inserts on the simulated caches. In the end, it reports the miss ratio for each tuple <cache_name, num_shard_bits, cache_capacity> in a output file. This PR also adds a main source block_cache_trace_analyzer so that we can run the analyzer in command line. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5449 Test Plan: Added tests for block_cache_trace_analyzer. COMPILE_WITH_ASAN=1 make check -j32. Differential Revision: D15797073 Pulled By: HaoyuHuang fbshipit-source-id: aef0c5c2e7938f3e8b6a10d4a6a50e6928ecf408	6 years ago
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	6 years ago