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 53C8B7E9B for ; Fri, 5 Aug 2011 02:39:32 +0000 (UTC) Received: (qmail 35130 invoked by uid 500); 5 Aug 2011 02:39:29 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 34852 invoked by uid 500); 5 Aug 2011 02:39:28 -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 34843 invoked by uid 99); 5 Aug 2011 02:39:26 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 05 Aug 2011 02:39:26 +0000 X-ASF-Spam-Status: No, hits=1.0 required=5.0 tests=FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FROM,HK_RANDOM_ENVFROM,HK_RANDOM_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of teddyyyy123@gmail.com designates 209.85.161.172 as permitted sender) Received: from [209.85.161.172] (HELO mail-gx0-f172.google.com) (209.85.161.172) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 05 Aug 2011 02:39:18 +0000 Received: by gxk19 with SMTP id 19so1659349gxk.31 for ; Thu, 04 Aug 2011 19:38:57 -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=Pz3X4n51Cwb7rYe5teiWSmQs5v7vsNy+pbmVlOqR3vg=; b=nbnT90SpRkIZ+21985feds9jM5ZQK4L42aITXCs3MmsxgVqeMLQOsC9E7pqzzxoIqC s8gqYdPIcjK32rRIz0Hk0TirCk5Ynwv2sANCnNOmlFB/3wVPlPuelD2YUDgNX9GMbctN xJ8aLO4+ADpBM1tpp5uPU9FK+PjZuZrXDtNfY= MIME-Version: 1.0 Received: by 10.236.173.194 with SMTP id v42mr2168617yhl.423.1312511937711; Thu, 04 Aug 2011 19:38:57 -0700 (PDT) Received: by 10.236.60.134 with HTTP; Thu, 4 Aug 2011 19:38:57 -0700 (PDT) Date: Thu, 4 Aug 2011 19:38:57 -0700 Message-ID: Subject: what is taking up my JVM heap space? From: Yang To: user@cassandra.apache.org Content-Type: text/plain; charset=ISO-8859-1 X-Virus-Checked: Checked by ClamAV on apache.org I ran my cassandra cluster on one node, inserted about 500000 rows, each about 400 bytes, then the heap went up to 800MB, and constantly goes into full GC. I guessed that the memtable was probably taking a lot of space, so I did a node tool flush, so that all memtable are changed to 0. after this, the heap came down a bit, to 500MB. but I thought it should be close to 0 right after the flush?? or else what is taking up the space? I'm still trying to look at the hprof file to figure out, but it seems difficult too Thanks Yang