Summary: Before this PR, `get_iostats_context()` will silently return a nullptr if no thread_local support is detected. This can be the result of build_detect_platform's failure to compile the simple code snippet on certain platforms, as reported in https://github.com/facebook/mysql-5.6/issues/904. To be safe, we should fail the compilation if user does not opt out IOStatsContext and ROCKSDB_SUPPORT_THREAD_LOCAL is not defined. If RocksDB relies on c++11, can we just always use thread_local? It turns out there might be performance concerns (https://github.com/facebook/rocksdb/issues/5774), which is beyond the scope of this PR. We can revisit this later. Here, we stick to the original impl. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8117 Reviewed By: ajkr Differential Revision: D27356847 Pulled By: riversand963 fbshipit-source-id: f7d5776842277598d8341b955febb601946801ae
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.