Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 80620 invoked from network); 14 Mar 2011 21:20:21 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 14 Mar 2011 21:20:21 -0000 Received: (qmail 9198 invoked by uid 500); 14 Mar 2011 21:20:19 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 9163 invoked by uid 500); 14 Mar 2011 21:20:19 -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 9155 invoked by uid 99); 14 Mar 2011 21:20:19 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 14 Mar 2011 21:20:19 +0000 X-ASF-Spam-Status: No, hits=-0.0 required=5.0 tests=RCVD_IN_DNSWL_LOW,SPF_NEUTRAL X-Spam-Check-By: apache.org Received-SPF: neutral (nike.apache.org: local policy) Received: from [74.125.83.44] (HELO mail-gw0-f44.google.com) (74.125.83.44) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 14 Mar 2011 21:20:10 +0000 Received: by gwb20 with SMTP id 20so2585553gwb.31 for ; Mon, 14 Mar 2011 14:19:49 -0700 (PDT) MIME-Version: 1.0 Received: by 10.150.48.15 with SMTP id v15mr6552289ybv.271.1300137588843; Mon, 14 Mar 2011 14:19:48 -0700 (PDT) Sender: scode@scode.org Received: by 10.151.79.11 with HTTP; Mon, 14 Mar 2011 14:19:48 -0700 (PDT) X-Originating-IP: [213.114.155.142] In-Reply-To: References: Date: Mon, 14 Mar 2011 22:19:48 +0100 X-Google-Sender-Auth: LjRa5VDlH-KbRNAasPmEQr9a-go Message-ID: Subject: Re: Calculate memory used for keycache From: Peter Schuller To: user@cassandra.apache.org Cc: ruslan usifov Content-Type: text/plain; charset=UTF-8 X-Virus-Checked: Checked by ClamAV on apache.org > How is it possible calculate this value? I think that key size, if we use > RandomPartitioner will 16 bytes so keycache will took 16*(num of keycache > elements) bytes ?? The easiest way right now is probably empirical testing. The issue is that the "memory use" must include overhead associated with the data structures involved, as well as longer-term effects like fragmentation in old-space in the GC (similarly to malloc/free). -- / Peter Schuller