charlesconnell opened a new pull request, #6857: URL: https://github.com/apache/hbase/pull/6857
Use of the `org.apache.hadoop.conf.Configuration` class to look up values is not super fast. It's fine most of the time, but in a very hot code path, it takes up noticeable CPU time. `ByteBuffDecompressor`'s are pooled and reused to avoid garbage collection churn. This means that sometimes their settings are not right for the block they're being asked to decompress. To handle this, before every decompression action, we call `ByteBuffDecompressor#reinit(Configuration)`, so it can pull settings from the Configuration in preparation for the decompression it's about to do. The `Configuration#get()` inside `reinit()` happens once per block, even though the settings it deals with are consistent across an entire table. Because the settings used by a `ByteBuffDecompressor` don't actually change within a table, we can pull the settings it needs from a `Configuration` when opening the HFile, and then not check again. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
