d755c62f92
Summary: This provides provides an implementation of PersistentCacheTier that is specialized for RAM. This tier does not persist data though. Why do we need this tier ? This is ideal as tier 0. This tier can host data that is too hot. Why can't we use Cache variants ? Yes you can use them instead. This tier can potentially outperform BlockCache in RAW mode by virtue of compression and compressed cache in block cache doesn't seem very popular. Potentially this tier can be modified to under stand the disadvantage of the tier below and retain data that the tier below is bad at handling (for example index and bloom data that is huge in size) Test Plan: Run unit tests added Subscribers: andrewkr, dhruba, leveldb Differential Revision: https://reviews.facebook.net/D57069
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/