szlta opened a new pull request, #3481: URL: https://github.com/apache/hive/pull/3481
BPWrapper is used in LRFU cache eviction policy to decrease the time spent waiting for lock on the heap. This is done by adding a buffer as threadlocal and accumulating CacheableBuffer instances there before trying to acquire a lock. This works well when we have threads from pools such as IO-Elevator threads or OrcEncode threads. For ephemeral threads there's no advantage of doing this as the buffers in threadlocals may never reach the heap or list structures of LRFU, thereby also making evictions less efficient. This can happen e.g. LLAPCacheAwareFS is used with Parquet, where we're using the Tez threads for both execution and IO. We should disable BPWrappers for such cases. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
