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 E36F5105AE for ; Mon, 26 Aug 2013 14:37:11 +0000 (UTC) Received: (qmail 22293 invoked by uid 500); 26 Aug 2013 14:37:09 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 22114 invoked by uid 500); 26 Aug 2013 14:37:08 -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 22106 invoked by uid 99); 26 Aug 2013 14:37:08 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 26 Aug 2013 14:37:08 +0000 X-ASF-Spam-Status: No, hits=2.2 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of girishkumarbk@gmail.com designates 209.85.192.181 as permitted sender) Received: from [209.85.192.181] (HELO mail-pd0-f181.google.com) (209.85.192.181) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 26 Aug 2013 14:37:02 +0000 Received: by mail-pd0-f181.google.com with SMTP id g10so3505889pdj.26 for ; Mon, 26 Aug 2013 07:36:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; bh=MxdGBwZW7lN59ApGco+yn1rOkVATDt2XY6Zf887kSqc=; b=EYzsaPdKhbVkiDhUbHvPZ7xBTuW9iHzOPMjBcfuMQGwaMnUCXn58damzv2EK3OwfoQ SLrKZ6PtU0RQbRCRyPx11LIyZzqIPyyVa7Of+i8YRtfm8q6G+RIe1OEP/ApRhWtF7FjK rvOKsL+Vyjv6OxWID26fpVD+b5OvXbSVwiMKyPkDihT2fWOY+1GYkbKA+Evjyy3sHFqp 9qOza1k+WSfdcN7vTPJi0S1JB2rmj2Qp8OMqkDgB1y9NYqv/ShuaD5GhtMzuWB+ltz4X AXxO9sWQ+AGJ3WjUKODCqPT6M0yCdPqlELrVAs9fMi94WfAQWcon+FG6OmNlgWPEa87w LMfw== X-Received: by 10.66.150.41 with SMTP id uf9mr14990448pab.108.1377527800997; Mon, 26 Aug 2013 07:36:40 -0700 (PDT) MIME-Version: 1.0 Received: by 10.66.25.235 with HTTP; Mon, 26 Aug 2013 07:36:20 -0700 (PDT) In-Reply-To: References: From: Girish Kumar Date: Mon, 26 Aug 2013 20:06:20 +0530 Message-ID: Subject: Re: Large # of Pending Tasks? To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=047d7b6d7f143f383004e4daaf4a X-Virus-Checked: Checked by ClamAV on apache.org --047d7b6d7f143f383004e4daaf4a Content-Type: text/plain; charset=ISO-8859-1 This is the 'Active Count' as observed on jconsole under 'org.apache.cassandra.request' ReadStage->Attributes. Below details... ActiveCount -> 12 .. Core Pool Size -> 192 Core Threads -> 192 CurrentlyBlockedTasks -> 0 MaximumThreads -> 192 PendingTasks -> 691 TotalBlockedTasks -> 0 I expect active count to go upto 192 as those many threads are available to handle requests ? Am I missing reading something here? I observe that Active Count never goes beyond 24 and Pending Tasks Count keeps building up? So question is what's the relation between Active count and max threads available in the pool for execution? Thanks, /BK On Mon, Aug 26, 2013 at 7:28 PM, Nate McCall wrote: > I'm not quite sure what you mean by 'active task count' - what is the > output of 'nodetool tpstats' when you run this test? > > > On Mon, Aug 26, 2013 at 4:39 AM, Girish Kumar wrote: > >> Hi, >> >> I'm using a single node Cassandra on 24 Core/48GB system. I have set my >> writers and readers (in yaml) to be around 192 for both and read and write. >> In this mode, when stressed with 192 threads for inserts and reads, what I >> observed via the jconsole of 'client request' the active read and write >> tasks never go beyond 24. However there are as many as 192 pending tasks. >> I was expecting Cassandra server to utilize the threads that are >> created using yaml and perform as many parallel inserts and reads. >> >> Why cassandra active task count doesn't go beyond 24 when the actual >> writers and readers are around 192 ? >> >> Any thoughts? >> /BK >> > > --047d7b6d7f143f383004e4daaf4a Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
This is the 'Active Count' as observed on jconsole= under 'org.apache.cassandra.request' ReadStage->Attributes. =A0= Below details...


ActiveCount -> 12
..
Core Pool Size -> 192
Core Threads -> 192=
CurrentlyBlockedTasks -> =A00
MaximumThreads -> = 192
PendingTasks -> 691
TotalBlockedTasks -> 0

I expect active count to go upto 192 as those many thre= ads are available to handle requests ? Am I missing reading something here?=

I observe that Active Count never goes beyond 24 = and Pending Tasks Count keeps building up?

So question is what's the relation between Active c= ount and max threads available in the pool for execution?

Thanks,
/BK





O= n Mon, Aug 26, 2013 at 7:28 PM, Nate McCall <nate@thelastpickle.com= > wrote:
I'm not quite sure what= you mean by 'active task count' - what is the output of 'nodet= ool tpstats' when you run this test?


=
On Mon, Aug 26, 2013 at 4:39 AM, Girish Kumar <girishkumarbk@gmail.com> wrote:
Hi,

I'= m using a single node=A0C= assandra=A0on 24 Core/48GB system. =A0I have set my writers and read= ers (in yaml) to be around 192 for both and read and write. =A0In this mode= , when stressed with 192 threads for inserts and reads, what I observed via= the jconsole of 'client request' the active read and write tasks n= ever go beyond 24. =A0However there are as many as 192 pending tasks. =A0I = was expecting=A0Cassandra= =A0server to utilize the threads that are created using yaml and per= form as many parallel inserts and reads.

Why=A0cassandra=A0active task count does= n't go beyond 24 when the actual writers and readers are around 192 ?

Any thoughts?
/BK


--047d7b6d7f143f383004e4daaf4a--