[ https://issues.apache.org/jira/browse/HAWQ-1030?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Goden Yao updated HAWQ-1030: ---------------------------- Fix Version/s: 2.0.1.0-incubating > User hang due to poor spin-lock/LWLock performance under high concurrency > ------------------------------------------------------------------------- > > Key: HAWQ-1030 > URL: https://issues.apache.org/jira/browse/HAWQ-1030 > Project: Apache HAWQ > Issue Type: Bug > Components: Core > Reporter: Ming LI > Assignee: Ming LI > Fix For: 2.0.1.0-incubating > > > Some clients have recently reported apparent hangs with their applications. > In all cases the symptoms were the same: > * All sessions appear to be hung in LWLockAcquire or Release, specifically > s_lock > * there is a high number of concurrent sessions (close to 100) > * System is not actually hung, normally processing resumes after some period > of time when all sessions have completed their locking work > The postgresql developer community has found several issues with performance > under high concurrency (> 32 sessions) in the spin-lock mechanism we've > inherited in HAWQ. This ultimately has been corrected in 9.5 with a > replacement to the spin-lock mechanism and appears to provide a significant > boost to query performance. > The actual fix is in commit: ab5194e6f617a9a9e7aadb3dd1cee948a42d0755 > Only 1 line commit to s_lock.c could help address this and would be easy > enough to cherry-pick: b03d196be055450c7260749f17347c2d066b4254 -- This message was sent by Atlassian JIRA (v6.3.4#6332)