Return-Path: X-Original-To: apmail-hbase-issues-archive@www.apache.org Delivered-To: apmail-hbase-issues-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id A34E511706 for ; Fri, 8 Aug 2014 06:30:16 +0000 (UTC) Received: (qmail 57221 invoked by uid 500); 8 Aug 2014 06:30:16 -0000 Delivered-To: apmail-hbase-issues-archive@hbase.apache.org Received: (qmail 57175 invoked by uid 500); 8 Aug 2014 06:30:16 -0000 Mailing-List: contact issues-help@hbase.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Delivered-To: mailing list issues@hbase.apache.org Received: (qmail 57159 invoked by uid 99); 8 Aug 2014 06:30:16 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 08 Aug 2014 06:30:16 +0000 Date: Fri, 8 Aug 2014 06:30:16 +0000 (UTC) From: "Lars Hofhansl (JIRA)" To: issues@hbase.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Resolved] (HBASE-11695) PeriodicFlusher and WakeFrequency issues MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/HBASE-11695?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Lars Hofhansl resolved HBASE-11695. ----------------------------------- Resolution: Invalid Not worth fixing. > PeriodicFlusher and WakeFrequency issues > ---------------------------------------- > > Key: HBASE-11695 > URL: https://issues.apache.org/jira/browse/HBASE-11695 > Project: HBase > Issue Type: Bug > Affects Versions: 0.94.21 > Reporter: Lars Hofhansl > Assignee: Lars Hofhansl > Priority: Minor > Attachments: 11695-trunk.txt > > > We just ran into a flush storm caused by the PeriodicFlusher. > Many memstore became eligible for flushing at exactly the same time, the effect we've seen is that the exact same region was flushed multiple times, because the flusher wakes up too often (every 10s). The jitter of 20s is larger than that and it takes some time to actually flush the memstore. > Here's one example. We've seen 100's of these, monopolizing the flush queue and preventing "important" flushes from happening. > {code} > 06-Aug-2014 20:11:56 [regionserver60020.periodicFlusher] INFO org.apache.hadoop.hbase.regionserver.HRegionServer[1397]-- regionserver60020.periodicFlusher requesting flush for region tsdb,\x00\x00\x0AO\xCF* \x00\x00\x01\x00\x01\x1F\x00\x00\x03\x00\x00\x0C,1340147003629.ef4a680b962592de910d0fdeb376dfc2. after a delay of 13449 > 06-Aug-2014 20:12:06 [regionserver60020.periodicFlusher] INFO org.apache.hadoop.hbase.regionserver.HRegionServer[1397]-- regionserver60020.periodicFlusher requesting flush for region tsdb,\x00\x00\x0AO\xCF* \x00\x00\x01\x00\x01\x1F\x00\x00\x03\x00\x00\x0C,1340147003629.ef4a680b962592de910d0fdeb376dfc2. after a delay of 14060 > {code} > So we need to increase the period of the PeriodicFlusher to at least the random jitter, also increase the default random jitter (20s does not help with many regions). -- This message was sent by Atlassian JIRA (v6.2#6252)