Miklos Szurap created HIVE-25074: ------------------------------------ Summary: Remove Metastore flushCache usage Key: HIVE-25074 URL: https://issues.apache.org/jira/browse/HIVE-25074 Project: Hive Issue Type: Improvement Components: Metastore, Standalone Metastore Affects Versions: 4.0.0 Reporter: Miklos Szurap
The "flushCache" in HiveMetaStore with the ObjectStore implementation is currently a NOOP: {code:java} public void flushCache() { // NOP as there's no caching } {code} The HBaseStore (HBaseReadWrite) had some logic in it, however it has been removed in HIVE-17234. As I see the calls are going like this: HiveMetaStoreClient.flushCache() -> CachedStore.flushCache() -> ObjectStore.flushCache() There are significant amount of calls (about 10% of all calls) made from the client to the server - to do nothing. We could spare the call to the server completely, including getting a DB connection which can take 1+ seconds under high load scenarios slowing down Hive queries unnecessarily. Can we: # Deprecate the RawStore.flushCache (if there are other implementations) # Deprecate the HiveMetaStoreClient.flushCache() # Do the NOOP on the client side in HiveMetaStoreClient.flushCache() (while it is not removed in a next version) -- This message was sent by Atlassian Jira (v8.3.4#803005)