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 1F08597CC for ; Sat, 7 Jan 2012 08:43:06 +0000 (UTC) Received: (qmail 20061 invoked by uid 500); 7 Jan 2012 08:43:03 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 19183 invoked by uid 500); 7 Jan 2012 08:42:56 -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 19153 invoked by uid 99); 7 Jan 2012 08:42:52 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Sat, 07 Jan 2012 08:42:52 +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 (athena.apache.org: local policy) Received: from [208.113.200.5] (HELO homiemail-a47.g.dreamhost.com) (208.113.200.5) by apache.org (qpsmtpd/0.29) with ESMTP; Sat, 07 Jan 2012 08:42:46 +0000 Received: from homiemail-a47.g.dreamhost.com (localhost [127.0.0.1]) by homiemail-a47.g.dreamhost.com (Postfix) with ESMTP id C4A2F28405B for ; Sat, 7 Jan 2012 00:42:24 -0800 (PST) DomainKey-Signature: a=rsa-sha1; c=nofws; d=thelastpickle.com; h=from :mime-version:content-type:subject:date:in-reply-to:to :references:message-id; q=dns; s=thelastpickle.com; b=TQl5lw55hJ B89256z/4FSNQng/N1SKSwMnLhUn9UDbdLQBQ+3piX2LU4NfDTH8sg8xJAOnjahZ tnSfdijIFnheoCNBYt8Cz96KdpA780vQ/3Iq/no65rHTFxoAl2yY3d4bCuSd16Hy ASHptIokqowWicWmiLapdvbbhvqFWXWIQ= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=thelastpickle.com; h=from :mime-version:content-type:subject:date:in-reply-to:to :references:message-id; s=thelastpickle.com; bh=sq80FIlK/RZOBvzC W/P7WFUwRAw=; b=0GThUwP3IqViQH3E2J76AnHmg5sLdo1DI8NqXusgEDoB/fqv HrJJYpHpsCW4mMR8lWYa/6s8na0Aqtai4Ul0xfeps0l5YWwHyL8imrJu1Ej5H7su YRynMr1urUcUsCCzfWvWcaDktSXftSSjctRhc6A8gbIAaB35ia3ZEFhbFK0= Received: from [172.16.1.4] (125-236-193-159.adsl.xtra.co.nz [125.236.193.159]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: aaron@thelastpickle.com) by homiemail-a47.g.dreamhost.com (Postfix) with ESMTPSA id BE231284058 for ; Sat, 7 Jan 2012 00:42:23 -0800 (PST) From: aaron morton Mime-Version: 1.0 (Apple Message framework v1251.1) Content-Type: multipart/alternative; boundary="Apple-Mail=_AE3720C4-2F1E-454B-B339-C631A60DF15E" Subject: Re: Pending on ReadStage Date: Sat, 7 Jan 2012 21:42:20 +1300 In-Reply-To: To: user@cassandra.apache.org References: Message-Id: <82832270-BC74-498B-BE26-29F592682794@thelastpickle.com> X-Mailer: Apple Mail (2.1251.1) --Apple-Mail=_AE3720C4-2F1E-454B-B339-C631A60DF15E Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=iso-8859-1 It may be IO, it's a good place to look=20 http://spyced.blogspot.com/2010/01/linux-performance-basics.html Look at the logs, when messages are dropped you will see logs from = StatusLogger that include TP stats and some other things.=20 Cheers ----------------- Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 7/01/2012, at 8:35 AM, Daning Wang wrote: > Thanks for your reply. >=20 > Nodes are equally balanced. and it is RandomPartitioner. I think that = machine is slower, Are you saying it is IO issue? >=20 > Daning >=20 > On Fri, Jan 6, 2012 at 10:25 AM, Mohit Anchlia = wrote: > Are all your nodes equally balanced in terms of read requests? Are you > using RandomPartitioner? Are you reading using indexes? >=20 > First thing you can do is compare iostat -x output between the 2 nodes > to rule out any io issues assuming your read requests are equally > balanced. >=20 > On Fri, Jan 6, 2012 at 10:11 AM, Daning Wang = wrote: > > Hi all, > > > > We have 5 nodes cluster(0.8.6), but the performance from one node is = way > > behind others, I checked tpstats, It always show non-zero pending = ReadStage, > > I don't see this problem on other nodes. > > > > What caused the problem? I/O? Memory? Cpu usage is still low. How to = fix > > this problem? > > > > ~/bin/nodetool -h localhost tpstats > > Pool Name Active Pending Completed = Blocked All > > time blocked > > ReadStage 11 15 56960 > > 0 0 > > RequestResponseStage 0 0 606695 > > 0 0 > > MutationStage 0 0 538634 > > 0 0 > > ReadRepairStage 0 0 199997 > > 0 0 > > ReplicateOnWriteStage 0 0 0 > > 0 0 > > GossipStage 0 0 5734 > > 0 0 > > AntiEntropyStage 0 0 0 > > 0 0 > > MigrationStage 0 0 0 > > 0 0 > > MemtablePostFlusher 0 0 7 > > 0 0 > > StreamStage 0 0 0 > > 0 0 > > FlushWriter 0 0 8 > > 0 0 > > MiscStage 0 0 0 > > 0 0 > > FlushSorter 0 0 0 > > 0 0 > > InternalResponseStage 0 0 0 > > 0 0 > > HintedHandoff 1 4 0 > > 0 0 > > > > Message type Dropped > > RANGE_SLICE 0 > > READ_REPAIR 0 > > BINARY 0 > > READ 9082 > > MUTATION 0 > > REQUEST_RESPONSE 0 > > > > Thanks you in advance. > > > > Daning > > >=20 --Apple-Mail=_AE3720C4-2F1E-454B-B339-C631A60DF15E Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=iso-8859-1 It = may be IO, it's a good place to look =

Look at the logs, when messages are dropped you will = see logs from StatusLogger that include TP stats and some other = things. 

Cheers

http://www.thelastpickle.com

On 7/01/2012, at 8:35 AM, Daning Wang wrote:

Thanks for = your reply.

Nodes are equally balanced. and it is = RandomPartitioner. I think that machine is slower, Are you saying it is = IO issue?

Daning

On Fri, Jan 6, = 2012 at 10:25 AM, Mohit Anchlia <mohitanchlia@gmail.com> wrote:
Are all = your nodes equally balanced in terms of read requests? Are you
using RandomPartitioner? Are you reading using indexes?

First thing you can do is compare iostat -x output between the 2 = nodes
to rule out any io issues assuming your read requests are equally
balanced.

On Fri, Jan 6, 2012 at 10:11 AM, Daning Wang <daning@netseer.com> wrote:
> Hi all,
>
> We have 5 nodes cluster(0.8.6), but the performance from one node = is way
> behind others, I checked tpstats, It always show non-zero pending = ReadStage,
> I don't see this problem on other nodes.
>
> What caused the problem? I/O? Memory? Cpu usage is still low. How = to fix
> this problem?
>
> ~/bin/nodetool -h localhost tpstats
> Pool = Name           &nbs= p;        Active   = Pending      Completed   = Blocked  All
> time blocked
> = ReadStage           = ;             = 11        = 15          56960
> = 0            &= nbsp;    0
> = RequestResponseStage         =      = 0         = 0         606695
> = 0            &= nbsp;    0
> = MutationStage          &= nbsp;          = 0         = 0         538634
> = 0            &= nbsp;    0
> = ReadRepairStage          = ;         = 0         = 0         199997
> = 0            &= nbsp;    0
> = ReplicateOnWriteStage         = ;    0         = 0            &= nbsp; 0
> = 0            &= nbsp;    0
> = GossipStage          &nb= sp;            = 0         = 0           5734
> = 0            &= nbsp;    0
> = AntiEntropyStage         &nbs= p;        = 0         = 0            &= nbsp; 0
> = 0            &= nbsp;    0
> = MigrationStage          =           = 0         = 0            &= nbsp; 0
> = 0            &= nbsp;    0
> = MemtablePostFlusher         &= nbsp;     = 0         = 0            &= nbsp; 7
> = 0            &= nbsp;    0
> = StreamStage          &nb= sp;            = 0         = 0            &= nbsp; 0
> = 0            &= nbsp;    0
> = FlushWriter          &nb= sp;            = 0         = 0            &= nbsp; 8
> = 0            &= nbsp;    0
> = MiscStage           = ;            &= nbsp; 0         = 0            &= nbsp; 0
> = 0            &= nbsp;    0
> = FlushSorter          &nb= sp;            = 0         = 0            &= nbsp; 0
> = 0            &= nbsp;    0
> = InternalResponseStage         = ;    0         = 0            &= nbsp; 0
> = 0            &= nbsp;    0
> = HintedHandoff          &= nbsp;          = 1         = 4            &= nbsp; 0
> = 0            &= nbsp;    0
>
> Message = type           = Dropped
> = RANGE_SLICE          &nb= sp;       0
> = READ_REPAIR          &nb= sp;       0
> = BINARY           &n= bsp;           0
> = READ           &nbs= p;          9082
> = MUTATION           =           0
> = REQUEST_RESPONSE         &nbs= p;   0
>
> Thanks you in advance.
>
> Daning
>


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