6b4cdacf41
Summary: Add flags `overwrite_probability` and `overwrite_window_size` flag to `db_bench`. Add the possibility of performing a `filluniquerandom` benchmark with an overwrite probability. For each write operation, there is a probability _p_ that the write is an overwrite (_p_=`overwrite_probability`). When an overwrite is decided, the key is randomly chosen from the last _N_ keys previously inserted into the DB (with _N_=`overwrite_window_size`). When a pure write is decided, the key inserted into the DB is unique and therefore will not be an overwrite. The `overwrite_window_size` is used so that the user can decide if the overwrite are mostly targeting recently inserted keys (when `overwrite_window_size` is small compared to the total number of writes), or can also target keys inserted "a long time ago" (when `overwrite_window_size` is comparable to total number of writes). Note that total number of writes = # of unique insertions + # of overwrites. No unit test specifically added. Local testing show the following **throughputs** for `filluniquerandom` with 1M total writes: - bypass the code inserts (no `overwrite_probability` flag specified): ~14.0MB/s - `overwrite_probability=0.99`, `overwrite_window_size=10`: ~17.0MB/s - `overwrite_probability=0.10`, `overwrite_window_size=10`: ~14.0MB/s - `overwrite_probability=0.99`, `overwrite_window_size=1M`: ~14.5MB/s - `overwrite_probability=0.10`, `overwrite_window_size=1M`: ~14.0MB/s Pull Request resolved: https://github.com/facebook/rocksdb/pull/8569 Reviewed By: pdillinger Differential Revision: D29818631 Pulled By: bjlemaire fbshipit-source-id: d472b4ea4e457a4da7c4ee4f14b40cccd6a4587a
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 especially 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/ and https://rocksdb.slack.com/
License
RocksDB is dual-licensed under both the GPLv2 (found in the COPYING file in the root directory) and Apache 2.0 License (found in the LICENSE.Apache file in the root directory). You may select, at your option, one of the above-listed licenses.