<div dir="ltr">Hi Pranith,<div><br></div><div>Thank you very much for the quick reply and the information. I am in the process now of recreating the cluster using XFS. This all brings up a few questions:</div><div><br></div><div>- I assume the change from EXT4 to XFS will correct the problem with readdir (in other words, the issue is not present in XFS)?</div><div>- Do you have any idea when the patch for this might be out? My reason for asking is that I have another cluster that has been updated to 3.6 and is running on EXT4 but does not yet have an issue. This concerns me so I am hoping the patch will be out soon?</div><div>- What exactly does cluster.entry-self-heal do? I can't seem to find a description of it?</div><div>- I assume from your posts that the reason the cluster is fine until traffic hits it is because the self-heal is not happening until traffic causes the files to be read. Is that how it works?</div><div><br></div><div>Thank you again for the fast response and the great product!</div><div><br></div><div>----</div><div>Kyle</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Nov 22, 2014 at 11:36 AM, Pranith Kumar Karampuri <span dir="ltr"><<a href="mailto:pkarampu@redhat.com" target="_blank">pkarampu@redhat.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div>On 11/22/2014 11:04 PM, Pranith Kumar
Karampuri wrote:<br>
</div>
<blockquote type="cite">
<br>
<div>On 11/22/2014 10:40 PM, Pranith Kumar
Karampuri wrote:<br>
</div>
<blockquote type="cite">
<br>
<div>On 11/22/2014 10:29 PM, Kyle Harris
wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div>Hello,</div>
<div><br>
</div>
<div>I have an issue with a 3 node replicated cluster. My
issue started after reboot a while back. The top command
would show the glusterfs and glusterfsd processes eating
up almost all the resources on an all three nodes of the
cluster. So much so that it would not run the web sites
that are hosted on it. The httpd processes would begin to
hang. I finally decided to tear down the cluster and
rebuild it from the ground up. I did so and then copied
all the data back which took all night due to the amount
of data. All was well during that entire copy process
back to the cluster with no resource spikes.<br>
</div>
</div>
</blockquote>
</blockquote>
Assuming you go back to 3.5.2<br>
Execute the following commands:<br>
# gluster volume set <volname> cluster.entry-self-heal off<br>
<br>
This should prevent httpd hangs.<br>
<br>
If you still find that the CPU usage is very high, execute the
following command:<br>
# gluster volume set <volname> cluster.self-heal-daemon off<br>
<br>
This disables self-healing. But you should probably periodically
heal so that the data is healed by enabling self-heal-daemon using
following command:<br>
# gluster volume set <volname> cluster.self-heal-daemon on<br>
<br>
Once "gluster volume heal <volname> info" shows zero
entries, then healing is complete.<br>
<br>
We took some steps to improve this in 3.6. But readdir in EXT4 is
not working correctly so that is probably giving problems here.
Lets wait for Vijay to merge the patch I mentioned, then things
should be fine.<br>
</blockquote></span>
Sorry for the inconvenience caused. We found the issue after the
release is made :-(.<span class="HOEnZb"><font color="#888888"><br>
<br>
Pranith</font></span><div><div class="h5"><br>
<blockquote type="cite"> <br>
Pranith<br>
<blockquote type="cite">
<blockquote type="cite">
<div dir="ltr">
<div><br>
</div>
<div>I should note that this cluster is home to many
Apache/PHP based web sites. The problem starts again,
however the minute I point traffic back to the sites on
the cluster. Before pointing traffic to it, all is fine
but as soon as the traffic begins to hit it, the
utilization again begins to spike. Note that all the
sites run just fine when hosted from a standard EXT4
partition. I noticed another thread labeled "glusterfsd
process thrashing CPU" where Pranith asks if the user has
directories with lots of files and I do.</div>
<div><br>
</div>
<div>Here are some other details of my cluster:</div>
<div>- OS: CentOS 6.6 with all updates on all 3 nodes as of
11-22-2014</div>
<div>- All 3 nodes have 8 cores with 16 GB of RAM</div>
<div>- Nodes are all formatted with EXT4</div>
<div>- All three nodes also have the files systems mounted
on them for use with Apache. I have experimented with
both NFS and Fuse mounts and it doesn't seem to make a
difference which I use for this particular problem. I am
currently using Fuse.</div>
<div>- Approximately 135 GB of data. Some deep directories
with many small files.</div>
<div>- No optimization or changes have been made to the
cluster . . . it is running with default options</div>
<div>- Gluster version 3.6.1-1 installed from RPMs</div>
<div>- Note the issue originally occurred on version 3.5.2
but I updated before rebuilding it in hopes that would fix
it (it didn't)</div>
<div><br>
</div>
<div>Can anyone give me guidance on how to tackle this
problem? I am hoping perhaps Pranith can give some
details as to why the question about many files and how to
proceed given my situation. I know others have commented
about having many small files with regard to performance
but when the processors are not spiked, performance has
been acceptable. Any help would be greatly appreciated.</div>
<div><br>
</div>
</div>
</blockquote>
Kyle,<br>
3.6.1 and EXT4 has a problem because of 64 bits offset.
Afr-v2 implementation introduced this problem. We thought the
following patch is merged but it didn't :-( <a href="http://review.gluster.com/8201" target="_blank">http://review.gluster.com/8201</a>.
Please don't use 3.6.1 with EXT4<br>
<br>
Vijay,<br>
Please merge <a href="http://review.gluster.com/8201" target="_blank">http://review.gluster.com/8201</a><br>
<br>
Pranith<br>
<blockquote type="cite">
<div dir="ltr">-- <br>
<div>
<div dir="ltr">Kyle
<div>
<div><br>
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</div>
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</div></div></div>
</blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr">Kyle A. Harris<div>Kyle@TheHarrisHome.com<br><div>615-364-6752<br></div><div><br></div></div></div></div>
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