ed0a4c93ef
Summary: With this PR, we can measure read-amp for queries where perf_context is enabled as follows: ``` SetPerfLevel(kEnableCount); Get(1, "foo"); double read_amp = static_cast<double>(get_perf_context()->block_read_byte / get_perf_context()->get_read_bytes); SetPerfLevel(kDisable); ``` Our internal infra enables perf_context for a sampling of queries. So we'll be able to compute the read-amp for the sample set, which can give us a good estimate of read-amp. Closes https://github.com/facebook/rocksdb/pull/2749 Differential Revision: D5647240 Pulled By: ajkr fbshipit-source-id: ad73550b06990cf040cc4528fa885360f308ec12
RocksDB: A Persistent Key-Value Store for Flash and RAM Storage
RocksDB is developed and maintained by Facebook Database Engineering Team. It is built on earlier work on LevelDB by Sanjay Ghemawat (sanjay@google.com) and Jeff Dean (jeff@google.com)
This code is a library that forms the core building block for a fast key value server, especially suited for storing data on flash drives. It has a Log-Structured-Merge-Database (LSM) design with flexible tradeoffs between Write-Amplification-Factor (WAF), Read-Amplification-Factor (RAF) and Space-Amplification-Factor (SAF). It has multi-threaded compactions, making it specially suitable for storing multiple terabytes of data in a single database.
Start with example usage here: https://github.com/facebook/rocksdb/tree/master/examples
See the github wiki for more explanation.
The public interface is in include/. Callers should not include or
rely on the details of any other header files in this package. Those
internal APIs may be changed without warning.
Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/