From user-return-27404-apmail-cassandra-user-archive=cassandra.apache.org@cassandra.apache.org Wed Jul 4 10:29:35 2012 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 D643EDAB9 for ; Wed, 4 Jul 2012 10:29:35 +0000 (UTC) Received: (qmail 59359 invoked by uid 500); 4 Jul 2012 10:29:33 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 59175 invoked by uid 500); 4 Jul 2012 10:29:33 -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 59166 invoked by uid 99); 4 Jul 2012 10:29:33 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 04 Jul 2012 10:29:33 +0000 X-ASF-Spam-Status: No, hits=2.2 required=5.0 tests=FSL_RCVD_USER,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-a94.g.dreamhost.com) (208.113.200.5) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 04 Jul 2012 10:29:27 +0000 Received: from homiemail-a94.g.dreamhost.com (localhost [127.0.0.1]) by homiemail-a94.g.dreamhost.com (Postfix) with ESMTP id 779FF38A059 for ; Wed, 4 Jul 2012 03:29:06 -0700 (PDT) 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=HmvYR5bB5D +Y2JJ4LebPpQkjsjHwDE2GRjdnwKHTvbMB+881h2uwIZLc6+YUdgZcAv+3apejj9 yPp9lmlYeazpH/00O6irvDT0TYEWKNyb3qFVtPHJ7kSgXQbFFdT86xWb6UtApzUX RTDTsC/fEvMZi28Jp9DXoLrZgfEbVB5EU= 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=0uUssUrKkrJ+7Mv/ Ol/NMF7MMOE=; b=cg7vpgZdjYRAAbxniNvJ39+y+K8o+OjYzOwlvWbtjS4cFKul OEyu/ln6oCHHSW/KdrwTVr6k8q7OExYWjzxtwLiA5DXuLdm2REvuHmpJdC0tMQnG JyoNVpZ6tTgcr3WnXv6fG0EEhAnA3iuwaxd7m6HuKXwh8RUzUJC4xCTG3jA= Received: from [172.16.1.4] (unknown [203.86.207.101]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: aaron@thelastpickle.com) by homiemail-a94.g.dreamhost.com (Postfix) with ESMTPSA id E39BE38A00C for ; Wed, 4 Jul 2012 03:29:05 -0700 (PDT) From: aaron morton Mime-Version: 1.0 (Apple Message framework v1278) Content-Type: multipart/alternative; boundary="Apple-Mail=_EE1EAEA1-5F8E-411E-A029-F607430CD61E" Subject: Re: frequent node up/downs Date: Wed, 4 Jul 2012 22:28:59 +1200 In-Reply-To: To: user@cassandra.apache.org References: <20120702121753.2A63.C3984673@terra.com.br> Message-Id: <09277B7E-4ADE-4FDE-99E7-ED386CCFADC4@thelastpickle.com> X-Mailer: Apple Mail (2.1278) X-Virus-Checked: Checked by ClamAV on apache.org --Apple-Mail=_EE1EAEA1-5F8E-411E-A029-F607430CD61E Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=iso-8859-1 > What accounts for the much larger virtual number? some kind of = off-heap memory?=20 http://wiki.apache.org/cassandra/FAQ#mmap > I'm a little puzzled as to why I would get such long pauses without = swapping.=20 The two are not related. On startup the JVM memory is locked so it will = not swap, from then on memory management is pretty much up the JVM.=20 Getting a lot of ParNew activity does not mean the JVM is low on memory, = it means there is a lot of activity in the new heap.=20 If you have a lot of insert activity (typically in a load test) you can = generate a lot of GC activity. Try reducing the load to a point where it = does not ht GC and then increase to find the cause. Also if you can = connect JConole to the JVM you may get a better view of the heap usage. Hope that helps.=20 ----------------- Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 3/07/2012, at 3:41 PM, feedly team wrote: > Couple more details. I confirmed that swap space is not being used = (free -m shows 0 swap) and cassandra.log has a message like "JNA = mlockall successful". top shows the process having 9g in resident memory = but 21.6g in virtual...What accounts for the much larger virtual number? = some kind of off-heap memory?=20 >=20 > I'm a little puzzled as to why I would get such long pauses without = swapping. I uncommented all the gc logging options in cassandra-env.sh = to try to see what is going on when the node freezes. >=20 > Thanks > Kireet >=20 > On Mon, Jul 2, 2012 at 9:51 PM, feedly team = wrote: > Yeah I noticed the leap second problem and ran the suggested fix, but = I have been facing these problems before Saturday and still see the = occasional failures after running the fix.=20 >=20 > Thanks. >=20 >=20 > On Mon, Jul 2, 2012 at 11:17 AM, Marcus Both = wrote: > Yeah! Look that. > = http://arstechnica.com/business/2012/07/one-day-later-the-leap-second-v-th= e-internet-scorecard/ > I had the same problem. The solution was rebooting. >=20 > On Mon, 2 Jul 2012 11:08:57 -0400 > feedly team wrote: >=20 > > Hello, > > I recently set up a 2 node cassandra cluster on dedicated = hardware. In > > the logs there have been a lot of "InetAddress xxx is now dead' or = UP > > messages. Comparing the log messages between the 2 nodes, they seem = to > > coincide with extremely long ParNew collections. I have seem some of = up to > > 50 seconds. The installation is pretty vanilla, I didn't change any > > settings and the machines don't seem particularly busy - cassandra = is the > > only thing running on the machine with an 8GB heap. The machine has = 64GB of > > RAM and CPU/IO usage looks pretty light. I do see a lot of 'Heap is = xxx > > full. You may need to reduce memtable and/or cache sizes' messages. = Would > > this help with the long ParNew collections? That message seems to be > > triggered on a full collection. >=20 > -- > Marcus Both >=20 >=20 >=20 --Apple-Mail=_EE1EAEA1-5F8E-411E-A029-F607430CD61E Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=iso-8859-1 What accounts for the much larger virtual = number? some kind of off-heap memory? http://wiki.apache.org/= cassandra/FAQ#mmap

I'm a little puzzled as to why I would get such long = pauses without swapping. 
The two are not = related. On startup the JVM memory is locked so it will not swap, from = then on memory management is pretty much up the = JVM. 

Getting a lot of ParNew activity = does not mean the JVM is low on memory, it means there is a lot of = activity in the new heap. 

If you have a = lot of insert activity (typically in a load test) you can generate a lot = of GC activity. Try reducing the load to a point where it does not ht GC = and then increase to find the cause. Also if you can connect JConole to = the JVM you may get a better view of the heap = usage.

Hope that = helps. 

http://www.thelastpickle.com

On 3/07/2012, at 3:41 PM, feedly team wrote:

Couple = more details. I confirmed that swap space is not being used (free -m = shows 0 swap) and cassandra.log has a message like "JNA mlockall = successful". top shows the process having 9g in resident memory but = 21.6g in virtual...What accounts for the much larger virtual number? = some kind of off-heap memory? 

I'm a little puzzled as to why I would get such long = pauses without swapping. I uncommented all the gc logging options in = cassandra-env.sh to try to see what is going on when the node = freezes.

Thanks
Kireet

On Mon, Jul 2, 2012 at 9:51 PM, feedly team <feedlydev@gmail.com> wrote:
Yeah I noticed the = leap second problem and ran the suggested fix, but I have been facing = these problems before Saturday and still see the occasional failures = after running the fix. 

Thanks.


On Mon, Jul 2, 2012 at 11:17 AM, Marcus Both <mboth@terra.com.br> = wrote:
Yeah! Look that.
http://arstechnica.com/business/2012/07/one-day-later-th= e-leap-second-v-the-internet-scorecard/
I had the same problem. The solution was rebooting.

On Mon, 2 Jul 2012 11:08:57 -0400
feedly team <feedlydev@gmail.com> wrote:

> Hello,
>    I recently set up a 2 node cassandra cluster on = dedicated hardware. In
> the logs there have been a lot of "InetAddress xxx is now dead' or = UP
> messages. Comparing the log messages between the 2 nodes, they seem = to
> coincide with extremely long ParNew collections. I have seem some = of up to
> 50 seconds. The installation is pretty vanilla, I didn't change = any
> settings and the machines don't seem particularly busy - cassandra = is the
> only thing running on the machine with an 8GB heap. The machine has = 64GB of
> RAM and CPU/IO usage looks pretty light. I do see a lot of 'Heap is = xxx
> full. You may need to reduce memtable and/or cache sizes' messages. = Would
> this help with the long ParNew collections? That message seems to = be
> triggered on a full collection.

--
Marcus Both




= --Apple-Mail=_EE1EAEA1-5F8E-411E-A029-F607430CD61E--