Return-Path: X-Original-To: apmail-cassandra-user-archive@www.apache.org Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 405A49E0E for ; Thu, 29 Sep 2011 18:15:06 +0000 (UTC) Received: (qmail 86211 invoked by uid 500); 29 Sep 2011 18:15:04 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 86183 invoked by uid 500); 29 Sep 2011 18:15:04 -0000 Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@cassandra.apache.org Delivered-To: mailing list user@cassandra.apache.org Received: (qmail 86175 invoked by uid 99); 29 Sep 2011 18:15:04 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 29 Sep 2011 18:15:04 +0000 X-ASF-Spam-Status: No, hits=0.0 required=5.0 tests=FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FROM,HK_RANDOM_ENVFROM,RCVD_IN_DNSWL_LOW,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of teddyyyy123@gmail.com designates 209.85.218.44 as permitted sender) Received: from [209.85.218.44] (HELO mail-yi0-f44.google.com) (209.85.218.44) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 29 Sep 2011 18:14:57 +0000 Received: by yic13 with SMTP id 13so987248yic.31 for ; Thu, 29 Sep 2011 11:14:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; bh=kijZTstrEVofGn72w9nQqtAYg3aiJKu7DSWV4Z8Mk3M=; b=E3bBDqzqj6ZNZdcSJp2byiHZvpX/iYGzoAQiPh+BFvWarOfZTfj51IOZtZtirkJwSb JD6gVeqwbBAQi7wkmRW7hqDxXgEeCX3hOM/cGQcv4HU30nTrk8+nEPpZaIvJfx5A2ZGX JvpV76FEizr7CGdCBvLVPDrQxcyosw613O5DA= MIME-Version: 1.0 Received: by 10.150.113.17 with SMTP id l17mr7744176ybc.167.1317320077127; Thu, 29 Sep 2011 11:14:37 -0700 (PDT) Received: by 10.151.14.20 with HTTP; Thu, 29 Sep 2011 11:14:37 -0700 (PDT) Date: Thu, 29 Sep 2011 11:14:37 -0700 Message-ID: Subject: StorageService.requestGC() ? From: Yang To: user@cassandra.apache.org Content-Type: text/plain; charset=ISO-8859-1 Table.getDataFileLocation() calls StorageService.requestGC(), which calls System.gc() I think I saw one GC in my log due to this code, and it caused a JVM freeze for 14 seconds. why do we need to call explicit GC ? thanks Yang [Times: user=2.81 sys=0.00, real=0.46 secs] 3472.943: [GC 3472.943: [ParNew: 21339139K->326984K(23592960K), 0.4742050 secs] 30764101K->10032251K(49807360K), 0.4743710 secs] [Times: user=2.91 sys=0.01, real=0.47 secs] 3519.043: [GC 3519.043: [ParNew: 21298504K->386099K(23592960K), 0.5201430 secs] 31003771K->10363088K(49807360K), 0.5203120 secs] [Times: user=3.15 sys=0.03, real=0.52 secs] 3560.277: [GC 3560.278: [ParNew: 21357619K->434850K(23592960K), 0.4693880 secs] 31334608K->10676370K(49807360K), 0.4695450 secs] [Times: user=2.92 sys=0.00, real=0.47 secs] 3601.343: [Full GC (System) 3601.343: [CMS: 10241519K->3496676K(26214400K), 14.6823750 secs] 28763882K->3496676K(49807360K), [CMS Perm : 27683K->27623K(27776K)], 14.6900120 secs] [Times: user=14.73 sys=0.00, real=14.69 secs] 3665.223: [GC 3665.224: [ParNew: 20971520K->361802K(23592960K), 0.2379040 secs] 24468196K->3858479K(49807360K), 0.2380660 secs] [Times: user=1.57 sys=0.01, real=0.23 secs] 3704.967: [GC 3704.968: [ParNew: 21333322K->359503K(23592960K), 0.4433910 secs] 24829999K->4173314K(49807360K), 0.4435500 secs] [Times: user=2.72 sys=0.02, real=0.44 secs] 3801.962: [GC 3801.962: [ParNew: 21331023K->388609K(23592960K), 0.5236180 secs] 25144834K->4479343K(49807360K), 0.5238240 secs] [Times: user=3.42 sys=0.00, real=0.53 secs]