[Gluster-devel] Fw: Re: Corvid gluster testing
Pranith Kumar Karampuri
pkarampu at redhat.com
Thu Aug 7 01:05:49 UTC 2014
hi Avati,
We checked this performance with plain distribute as well and on nfs
it gave 25 minutes where as on nfs it gave around 90 minutes after
disabling throttling in both situations. I was wondering if any of you
guys know what could contribute to this difference.
Pranith
On 08/07/2014 01:33 AM, Anand Avati wrote:
> Seems like heavy FINODELK contention. As a diagnostic step, can you
> try disabling eager-locking and check the write performance again
> (gluster volume set $name cluster.eager-lock off)?
>
>
> On Tue, Aug 5, 2014 at 11:44 AM, David F. Robinson
> <david.robinson at corvidtec.com <mailto:david.robinson at corvidtec.com>>
> wrote:
>
> Forgot to attach profile info in previous email. Attached...
> David
> ------ Original Message ------
> From: "David F. Robinson" <david.robinson at corvidtec.com
> <mailto:david.robinson at corvidtec.com>>
> To: gluster-devel at gluster.org <mailto:gluster-devel at gluster.org>
> Sent: 8/5/2014 2:41:34 PM
> Subject: Fw: Re: Corvid gluster testing
>> I have been testing some of the fixes that Pranith incorporated
>> into the 3.5.2-beta to see how they performed for moderate levels
>> of i/o. All of the stability issues that I had seen in previous
>> versions seem to have been fixed in 3.5.2; however, there still
>> seem to be some significant performance issues. Pranith
>> suggested that I send this to the gluster-devel email list, so
>> here goes:
>> I am running an MPI job that saves a restart file to the gluster
>> file system. When I use the following in my fstab to mount the
>> gluster volume, the i/o time for the 2.5GB file is roughly
>> 45-seconds.
>> / gfsib01a.corvidtec.com:/homegfs /homegfs glusterfs
>> transport=tcp,_netdev 0 0
>> /
>> When I switch this to use the NFS protocol (see below), the i/o
>> time is 2.5-seconds.
>> / gfsib01a.corvidtec.com:/homegfs /homegfs nfs
>> vers=3,intr,bg,rsize=32768,wsize=32768 0 0/
>> The read-times for gluster are 10-20% faster than NFS, but the
>> write times are almost 20x slower.
>> I am running SL 6.4 and glusterfs-3.5.2-0.1.beta1.el6.x86_64...
>> /[root at gfs01a glusterfs]# gluster volume info homegfs
>> Volume Name: homegfs
>> Type: Distributed-Replicate
>> Volume ID: 1e32672a-f1b7-4b58-ba94-58c085e59071
>> Status: Started
>> Number of Bricks: 2 x 2 = 4
>> Transport-type: tcp
>> Bricks:
>> Brick1: gfsib01a.corvidtec.com:/data/brick01a/homegfs
>> Brick2: gfsib01b.corvidtec.com:/data/brick01b/homegfs
>> Brick3: gfsib01a.corvidtec.com:/data/brick02a/homegfs
>> Brick4: gfsib01b.corvidtec.com:/data/brick02b/homegfs/
>> David
>> ------ Forwarded Message ------
>> From: "Pranith Kumar Karampuri" <pkarampu at redhat.com
>> <mailto:pkarampu at redhat.com>>
>> To: "David Robinson" <david.robinson at corvidtec.com
>> <mailto:david.robinson at corvidtec.com>>
>> Cc: "Young Thomas" <tom.young at corvidtec.com
>> <mailto:tom.young at corvidtec.com>>
>> Sent: 8/5/2014 2:25:38 AM
>> Subject: Re: Corvid gluster testing
>> gluster-devel at gluster.org <mailto:gluster-devel at gluster.org> is
>> the email-id for the mailing list. We should probably start with
>> the initial run numbers and the comparison for glusterfs mount
>> and nfs mounts. May be something like
>> glusterfs mount: 90 minutes
>> nfs mount: 25 minutes
>> And profile outputs, volume config, number of mounts, hardware
>> configuration should be a good start.
>> Pranith
>> On 08/05/2014 09:28 AM, David Robinson wrote:
>>> Thanks pranith
>>> ===============================
>>> David F. Robinson, Ph.D.
>>> President - Corvid Technologies
>>> 704.799.6944 x101 <tel:704.799.6944%20x101> [office]
>>> 704.252.1310 <tel:704.252.1310> [cell]
>>> 704.799.7974 <tel:704.799.7974> [fax]
>>> David.Robinson at corvidtec.com <mailto:David.Robinson at corvidtec.com>
>>> http://www.corvidtechnologies.com
>>> <http://www.corvidtechnologies.com/>
>>>> On Aug 4, 2014, at 11:22 PM, Pranith Kumar Karampuri
>>>> <pkarampu at redhat.com <mailto:pkarampu at redhat.com>> wrote:
>>>>> On 08/05/2014 08:33 AM, Pranith Kumar Karampuri wrote:
>>>>> On 08/05/2014 08:29 AM, David F. Robinson wrote:
>>>>>>>> On 08/05/2014 12:51 AM, David F. Robinson wrote:
>>>>>>>> No. I don't want to use nfs. It eliminates most of the
>>>>>>>> benefits of why I want to use gluster. Failover redundancy
>>>>>>>> of the pair, load balancing, etc.
>>>>>>> What is the meaning of 'Failover redundancy of the pair,
>>>>>>> load balancing ' Could you elaborate more? smb/nfs/glusterfs
>>>>>>> are just access protocols that gluster supports
>>>>>>> functionality is almost same
>>>>>> Here is my understanding. Please correct me where I am wrong.
>>>>>> With gluster, if I am doing a write and one of the replicated
>>>>>> pairs goes down, there is no interruption to the I/o. The
>>>>>> failover is handled by gluster and the fuse client. This
>>>>>> isn't done if I use an nfs mount unless the component of the
>>>>>> pair that goes down isn't the one I used for the mount.
>>>>>> With nfs, I will have to mount one of the bricks. So, if I
>>>>>> have gfs01a, gfs01b, gfs02a, gfs02b, gfs03a, gfs03b, etc and
>>>>>> my fstab mounts gfs01a, it is my understanding that all of my
>>>>>> I/o will go through gfs01a which then gets distributed to all
>>>>>> of the other bricks. Gfs01a throughput becomes a bottleneck.
>>>>>> Where if I do a gluster mount using fuse, the load balancing
>>>>>> is handled at the client side , not the server side. If I
>>>>>> have 1000-nodes accessing 20-gluster bricks, I need the load
>>>>>> balancing aspect. I cannot have all traffic going through the
>>>>>> network interface on a single brick.
>>>>>> If I am wrong with the above assumptions, I guess my question
>>>>>> is why would one ever use the gluster mount instead of nfs
>>>>>> and/or samba?
>>>>>> Tom: feel free to chime in if I have missed anything.
>>>>> I see your point now. Yes the gluster server where you did the
>>>>> mount is kind of a bottle neck.
>>>> Now that we established the problem is in the
>>>> clients/protocols, you should send out a detailed mail on
>>>> gluster-devel and see if anyone can help with you on
>>>> performance xlators that can improve it a bit more. My area of
>>>> expertise is more on replication. I am sub-maintainer for
>>>> replication,locks components. I also know connection
>>>> management/io-threads related issues which lead to hangs as I
>>>> worked on them before. Performance xlators are black box to me.
>>>> Performance xlators are enabled only on fuse gluster stack. On
>>>> nfs server mounts we disable all the performance xlators except
>>>> write-behind as nfs client does lots of things for improving
>>>> performance. I suggest you guys follow up more on gluster-devel.
>>>> Appreciate all the help you did for improving the product :-).
>>>> Thanks a ton!
>>>> Pranith
>>>>> Pranith
>>>>>> David (Sent from mobile)
>>>>>> ===============================
>>>>>> David F. Robinson, Ph.D.
>>>>>> President - Corvid Technologies
>>>>>> 704.799.6944 x101 <tel:704.799.6944%20x101> [office]
>>>>>> 704.252.1310 <tel:704.252.1310> [cell]
>>>>>> 704.799.7974 <tel:704.799.7974> [fax]
>>>>>> David.Robinson at corvidtec.com
>>>>>> <mailto:David.Robinson at corvidtec.com>
>>>>>> http://www.corvidtechnologies.com
>>>>>> <http://www.corvidtechnologies.com/>
>
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