[ https://issues.apache.org/jira/browse/HDDS-2301?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Rajesh Balamohan updated HDDS-2301: ----------------------------------- Labels: performance (was: ) > Write path: Reduce read contention in rocksDB > --------------------------------------------- > > Key: HDDS-2301 > URL: https://issues.apache.org/jira/browse/HDDS-2301 > Project: Hadoop Distributed Data Store > Issue Type: Bug > Affects Versions: 0.5.0 > Reporter: Rajesh Balamohan > Assignee: Nanda kumar > Priority: Major > Labels: performance > Attachments: om_write_profile.png > > > Benchmark: > ------------ > Simple benchmark which creates 100 and 1000s of keys (empty directory) in > OM. This is done in a tight loop and multiple threads from client side to add > enough load on CPU. Note that intention is to understand the bottlenecks in > OM (intentionally avoiding interactions with SCM & DN). > Observation: > ------------- > During write path, Ozone checks {{OMFileRequest.verifyFilesInPath}}. This > internally calls {{omMetadataManager.getKeyTable().get(dbKeyName)}} for every > write operation. This turns out to be expensive and chokes the write path. > [https://github.com/apache/hadoop/blob/trunk/hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/request/file/OMDirectoryCreateRequest.java#L155] > [https://github.com/apache/hadoop/blob/trunk/hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/request/file/OMFileRequest.java#L63] > In most of the cases, directory creation would be fresh entry. In such cases, > it would be good to try with {{RocksDB::keyMayExist.}} > > -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org