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 7697D11B0E for ; Sun, 8 Jun 2014 15:28:22 +0000 (UTC) Received: (qmail 72649 invoked by uid 500); 8 Jun 2014 15:28:19 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 72605 invoked by uid 500); 8 Jun 2014 15:28:19 -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 72596 invoked by uid 99); 8 Jun 2014 15:28:19 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 08 Jun 2014 15:28:19 +0000 X-ASF-Spam-Status: No, hits=4.4 required=5.0 tests=FREEMAIL_ENVFROM_END_DIGIT,HTML_MESSAGE,RCVD_IN_BL_SPAMCOP_NET,RCVD_IN_DNSWL_NONE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of asf11@outlook.com designates 65.54.190.140 as permitted sender) Received: from [65.54.190.140] (HELO BAY004-OMC3S2.hotmail.com) (65.54.190.140) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 08 Jun 2014 15:28:15 +0000 Received: from BAY169-W121 ([65.54.190.187]) by BAY004-OMC3S2.hotmail.com with Microsoft SMTPSVC(7.5.7601.22701); Sun, 8 Jun 2014 08:27:50 -0700 X-TMN: [dLvV8FngN0WL4zicIJzhRIzS7CD8llBL] X-Originating-Email: [asf11@outlook.com] Message-ID: Content-Type: multipart/alternative; boundary="_6f437ec6-8b33-43dc-b4aa-98345dc998b5_" From: S C To: "user@cassandra.apache.org" Subject: high pending compactions Date: Sun, 8 Jun 2014 10:27:50 -0500 Importance: Normal MIME-Version: 1.0 X-OriginalArrivalTime: 08 Jun 2014 15:27:50.0613 (UTC) FILETIME=[357CA850:01CF832E] X-Virus-Checked: Checked by ClamAV on apache.org --_6f437ec6-8b33-43dc-b4aa-98345dc998b5_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I am using Cassandra 1.1 (sorry bit old) and I am seeing high pending compa= ction count. "pending tasks: 67" while active compaction tasks are not more= than 5. I have a 24CPU machine. Shouldn't I be seeing more compactions? Is= this a pattern of high writes and compactions backing up? How can I improv= e this? Here are my thoughts. Increase memtable_total_space_in_mbIncrease compaction_throughput_mb_per_se= cIncrease concurrent_compactions Sorry if this was discussed already. Any pointers is much appreciated.=20 Thanks=2CKumar = --_6f437ec6-8b33-43dc-b4aa-98345dc998b5_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

I am using Cassandra 1.1 (sorry = bit old) and I am seeing high pending compaction count. =3B"pending tasks: 67" while active compaction tasks a= re not more than 5. I have a 24CPU machine. Shouldn't I be seeing more comp= actions? Is this a pattern of high writes and compactions backing up? How c= an I improve this? Here are my thoughts.

Increase memtable_total_space_in_mb=

Increase compaction_thro= ughput_mb_per_sec

Increas= e concurrent_compactions

Sorry if this was discussed already. Any p= ointers is much appreciated. =3B

Thanks= =2C

Kumar

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