Hello, We have started to evaluate MyRocks 3 months ago, our DBs were initially empty and now they have reached 500 GB on-disk. We experience severe performance issues, and we have the feelings it could be better.
https://github.com/facebook/rocksdb/wiki/RocksDB-Tuning-Guide is interesting, especially the "Universal Compaction" section: « Universal compaction has a size limitation. Please be careful when your DB (or column family) size is over 100GB. » I don't think that write amplification is a bottleneck for our application, so my obvious first question is: What compaction style is used in MariaDB and how to make sure that Level Style Compaction is used ? Also, we haven't set any 'rocksdb_*' option. The default configuration may not be appropriate in our case. For example, rocksdb_block_cache_size (default: 512MB) seems to be one of the most important options, similarly to innodb_buffer_pool_size and tokudb_cache_size, although I have never understood why (see my unanswered question at https://lists.launchpad.net/maria-discuss/msg02683.html ). Although the DB is much bigger than RAM (128 GB), RAM should be big enough to contain the active working set. Julien _______________________________________________ Mailing list: https://launchpad.net/~maria-discuss Post to : maria-discuss@lists.launchpad.net Unsubscribe : https://launchpad.net/~maria-discuss More help : https://help.launchpad.net/ListHelp
