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Sergiu Prodan edited comment on HTTPCORE-433 at 9/19/16 2:29 PM: ----------------------------------------------------------------- Added two screenshots of thread visualisation when making requests from 10 threads. PoolingHttpClientConnectionManager#setValidateAfterInactivity set to 1 and 2000 respectively was (Author: sergiuprodan): Thread visualisation when making requests from 10 different threads. PoolingHttpClientConnectionManager#setValidateAfterInactivity set to 1 > Setting validateAfterInactivity to 1ms increases lock contention in > AbstractConnPool > ------------------------------------------------------------------------------------ > > Key: HTTPCORE-433 > URL: https://issues.apache.org/jira/browse/HTTPCORE-433 > Project: HttpComponents HttpCore > Issue Type: Bug > Components: HttpCore > Affects Versions: 4.4.4 > Reporter: Sergiu Prodan > Attachments: httpclient_thread_dump, > threads_when_inactivity_set_to_1.png, threads_when_inactivity_set_to_2000.png > > > This issue was observed after upgrading to httpclient v4.5.2 and httpcore > v4.4.4. > When configuring the PoolingHttpClientConnectionManager, I have set > validateAfterInactivity to 1ms as this is the only way of maintaining the old > behaviour, i.e. checking every connection if is stale before using it. > I have observed a performance degradation under high load when the httpclient > is shared between multiple threads. > After taking a thread dump, one thing that got my attention was several > threads waiting for same ReentrantLock instance while trying to > AbstractConnPool#getPoolEntryBlocking/AbstractConnPool#release. The > ReentrantLock instance in question was owned by another thread performing > CPool#validate. > It seems to me that performing this stale check inside the region protected > by this lock is unnecessary and also induces a big performance hit when using > the httpclient from multiple threads. > I've atached a thread dump of a test application that reproduces this > behaviour. ReentrantLock in question in this thread dump is > 0x0000000706e8b9a8 and is owned by Thread-4 -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@hc.apache.org For additional commands, e-mail: dev-h...@hc.apache.org