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Kihwal Lee commented on HDFS-6599: ---------------------------------- There have been many performance improvements since 2.3. Examples: HDFS-7097 and HDFS-7615 fix writers being unfairly penalized. HDFS-7217 reduces the write locking of namesystem by 30-40%. This is a big deal for busy clusters. If you use the audit logging, try async audit logging (HDFS-5241). This should be already in 2.3. > 2.4 addBlock is 10 to 20 times slower compared to 0.23 > ------------------------------------------------------ > > Key: HDFS-6599 > URL: https://issues.apache.org/jira/browse/HDFS-6599 > Project: Hadoop HDFS > Issue Type: Bug > Affects Versions: 2.3.0, 2.4.0 > Reporter: Kihwal Lee > Assignee: Daryn Sharp > Priority: Blocker > Fix For: 2.5.0 > > Attachments: HDFS-6599.patch > > > From one of our busiest 0.23 clusters: > {panel} > "AddBlockAvgTime" : 0.9514711501719515 > "CreateAvgTime" : 1.7564162389174 > "CompleteAvgTime" : 1.3310406035056548 > "BlockReceivedAndDeletedAvgTime" : 0.661210005151392 > {panel} > From a not-so-busy 2.4 cluster: > {panel} > "AddBlockAvgTime" : 10.083333333333334 > "CreateAvgTime" : 1.0 > "CompleteAvgTime" : 1.1111111111111112 > "BlockReceivedAndDeletedAvgTime" : 0.07692307692307694 > {panel} > When the 2.4 cluster gets a moderate amount of write requests, the latency is > terrible. E.g. addBlock goes upward of 60ms. -- This message was sent by Atlassian JIRA (v6.3.4#6332)