Return-Path: 
 <dev-return-22558-apmail-hbase-dev-archive=hbase.apache.org@hbase.apache.org>
X-Original-To: apmail-hbase-dev-archive@www.apache.org
Delivered-To: apmail-hbase-dev-archive@www.apache.org
Received: from mail.apache.org (hermes.apache.org [140.211.11.3])
	by minotaur.apache.org (Postfix) with SMTP id 7E74E24E1
	for <apmail-hbase-dev-archive@www.apache.org>;
 Fri, 29 Apr 2011 02:51:59 +0000 (UTC)
Received: (qmail 99286 invoked by uid 500); 29 Apr 2011 02:51:59 -0000
Delivered-To: apmail-hbase-dev-archive@hbase.apache.org
Received: (qmail 99218 invoked by uid 500); 29 Apr 2011 02:51:59 -0000
Mailing-List: contact dev-help@hbase.apache.org; run by ezmlm
Precedence: bulk
List-Help: <mailto:dev-help@hbase.apache.org>
List-Unsubscribe: <mailto:dev-unsubscribe@hbase.apache.org>
List-Post: <mailto:dev@hbase.apache.org>
List-Id: <dev.hbase.apache.org>
Reply-To: dev@hbase.apache.org
Delivered-To: mailing list dev@hbase.apache.org
Received: (qmail 99210 invoked by uid 99); 29 Apr 2011 02:51:58 -0000
Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230)
    by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 29 Apr 2011 02:51:58 +0000
X-ASF-Spam-Status: No, hits=1.5 required=5.0
	tests=FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_LOW,RFC_ABUSE_POST,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL
X-Spam-Check-By: apache.org
Received-SPF: pass (nike.apache.org: domain of lohit.vijayarenu@gmail.com
 designates 209.85.216.176 as permitted sender)
Received: from [209.85.216.176] (HELO mail-qy0-f176.google.com)
 (209.85.216.176)
    by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 29 Apr 2011 02:51:51 +0000
Received: by qyk30 with SMTP id 30so2272090qyk.14
        for <dev@hbase.apache.org>; Thu, 28 Apr 2011 19:51:30 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=gamma;
        h=domainkey-signature:mime-version:in-reply-to:references:date
         :message-id:subject:from:to:content-type;
        bh=BXW91vZToNoD8d8bqRfCs1k/EJJX29dnIBaKt3ChWwk=;
        b=NRzpOOOVm2O+y9I2fr8l5kA8u37XxIxaszsBhesn46s3eIo4RIN38K4BpaV641/Iwh
         KFIdhMivt4YUtQb3u6glAtMXtAivJhA9NSIJNEcPOQg/FQU1s8gICL2hRM8PUeSn0BBS
         nfWSW4+mZqzYJgYLFB3T4QpmYDM93+EOEAphk=
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=mime-version:in-reply-to:references:date:message-id:subject:from:to
         :content-type;
        b=rOdZBbY6PStctWRXLbbhpMJ8Hmuf2Q3R1HPhSy4QupoocciKYeMcozDV1AELdJlvX6
         ROiJjwLCWY14cBtJgoNRNKNhDb1dKgAwVQmsMf5iXtfuLE0IQzcj3OoJqFIruJdY/e/R
         3fc35wmL6RW6JjJQE60FfokYINU7q7NUzyCNw=
MIME-Version: 1.0
Received: by 10.224.213.8 with SMTP id gu8mr3504485qab.320.1304045490619; Thu,
 28 Apr 2011 19:51:30 -0700 (PDT)
Received: by 10.229.221.75 with HTTP; Thu, 28 Apr 2011 19:51:30 -0700 (PDT)
In-Reply-To: <BANLkTingJ5p1bRh7TKnpLabaWEuTPDc1sw@mail.gmail.com>
References: <BANLkTinY-jc8nwXZJSgmFVhEm+Ro9sp0ug@mail.gmail.com>
	<BANLkTingJ5p1bRh7TKnpLabaWEuTPDc1sw@mail.gmail.com>
Date: Thu, 28 Apr 2011 19:51:30 -0700
Message-ID: <BANLkTimAV9WXcNCvszLh_P=J+bfA-7tPsQ@mail.gmail.com>
Subject: Re: HConnectionManager max cached instances
From: lohit <lohit.vijayarenu@gmail.com>
To: dev@hbase.apache.org
Content-Type: multipart/alternative; boundary=20cf300fb3293d464b04a205c0f0
X-Virus-Checked: Checked by ClamAV on apache.org

--20cf300fb3293d464b04a205c0f0
Content-Type: text/plain; charset=UTF-8

Thanks for the pointer. Even if we increase
hbase.zookeeper.property.maxClientCnxns
wouldn't the cache size still be 31?
I was wondering if there was way to avoid cache miss so that it would not
create new ZK connection.

2011/4/28 Ted Yu <yuzhihong@gmail.com>

> Increase value for the following parameter:
>  <property>
>    <name>hbase.zookeeper.property.maxClientCnxns</name>
>    <value>30</value>
>
> Please read my blog for long-term fix which should be commited soon:
>
> http://zhihongyu.blogspot.com/2011/04/managing-connections-in-hbase-090-and.html
>
> On Thu, Apr 28, 2011 at 7:26 PM, lohit <lohit.vijayarenu@gmail.com> wrote:
>
> > Hi,
> >
> > By looking at HConnectionManager it looks like from a single node a max
> of
> > 31 connections can be cached.
> >
> > >  static final int MAX_CACHED_HBASE_INSTANCES = 31;
> >
> > I read the comment that this is based on the assumption that max client
> > connections to zookeeper is 30 from a single node.
> > ZooKeeper has an option to change that value, but we seem to be doing lot
> > of
> > cache misses if we made more than 30 connections from a client.
> > This cache miss end up making new ZK connection and if number of HTable
> > operations are more, we see spike in ZooKeeper connections from single
> > node.
> >
> > This is seen in hbase.0.90.2. Is there any work around for this apart
> from
> > change the code?
> >
> > --
> > Thanks
> > Lohit
> >
>



-- 
Have a Nice Day!
Lohit

--20cf300fb3293d464b04a205c0f0--