[Gluster-users] Separating reads and writes for performance benefit

[Haris Zukanovic]

Francisics,
Your english is perfect :)
As is your solution. Thank you.

The mount with bind works flawlessly.
I just need to put the brick somewhere and forget about it.. because it 
will still be writable ofcourse..
The mount is good because it is a separated path which can be given to 
an application for reading with good performance while the gluster mount 
can be given to it for writes.



kind regards
Haris

On 23/03/12 10.33, Francsics Balázs wrote:
> Hy,
>
> I've further investigated your problem, and found a solution, with a test setup.
>
> i've created a volume:
> # gluster volume create test replica 2 transport tcp node1:/brick node1:/brick2
> # gluster volume start test
>
> then mounted with gluster:
> # mount.glusterfs node1:/test /mnt
>
> mounted the brick directly to a read-only directory, with --bind:
> # mount --bind /brick ~/test_read_only
> # mount --bind -o remount,ro /brick ~/test_read_only
>
> # touch ~/test_read_only/file
> touch: cannot touch `teszt/asd': Read-only file system
>
> Becouse it's a bind mount to the native brick, on ext4 filesystem, it has better performance for read, than through cluster mount, and the read-only mount prevents any file writes. This works only if you need to access the files on the same machine, which the gluster runs.
>
> Ps: sorry for my terrible english :)
>
> --
> Üdvözlettel,
> Francsics Balázs
> Netrix Internet
>
>
> On Friday, March 23, 2012 at 9:12 AM, Haris Zukanovic wrote:
>
>> Hi Francis,
>>
>> Thanx for the suggestion..
>>
>> I tried this. I set 644 owner root on the brick directory.
>> Apache is not able to read the PHP files from under the brick folder.
>> 2012/03/23 09:04:32 [crit] 15752#0: *137813 stat() "/var/www/gluster-application-read-only/www/staging/failover-test/web/server-health.php" failed (13: Permission denied), client: *.*.107.216, server: *.failover.myserver.com (http://failover.myserver.com), request: "GET /server-health.php HTTP/1.1", host: "test.failover.myserver.com (http://test.failover.myserver.com)"
>>
>> Apache seems to be unable to change into brick dir since it has no x permission.
>> If I set the x for other users (apache) on the brick then since apache user is owner of all the files it will be able to overwrite it also using the path directly through the brick.
>> I maybe missing something?
>>
>>
>>
>> On 23/03/12 08.20, Francsics Balázs wrote:
>>> Gluster runs on the gluster user, right? If you set the brick permission to 644, and you read the files with a different user, you cannot write to the dir.
>>>
>>> --
>>> Francsics Balázs
>>> Sent with Sparrow (http://www.sparrowmailapp.com/?sig)
>>>
>>>
>>> On 2012. March 22., Thursday at 22:18, Haris Zukanovic wrote:
>>>
>>>> Great to hear that...
>>>> All my tests so far have also confirmed that there are no problems when you only read from the brick dir.
>>>> However, I would like somehow to prevent accidentals writes if possible. Do you have any suggestions on how to accomplish that?
>>>> In fact, I am unable to allow writes to a file through the Gluster mount and allow to read but not write on the brick directory directly.
>>>>
>>>>
>>>>
>>>> On 22/03/12 20.47, winyaa at gmail.com (mailto:winyaa at gmail.com) wrote:
>>>>> If you are on the same machine, which the gluster runs from, and you are using replicated setup, you can read from the brick directly, but avoid to write into the brick dir, becouse it leads to data inconsistency.
>>>>> 2012.03.22. 20:06, "Haris Zukanovic"<haris.zukanovic74 at gmail.com (mailto:haris.zukanovic74 at gmail.com)>  ezt írta:
>>>>>> Thanx for your input...
>>>>>> Do you mean that I should mount the brick through NFS to make the brick read-only? I would like to avioid that. I am on the same physical machine where the brick is.
>>>>>>
>>>>>>
>>>>>> On 22/03/12 19.56, Berend de Boer wrote:
>>>>>>>>>>>> "Haris" == Haris Zukanovic<haris.zukanovic74 at gmail.com (mailto:haris.zukanovic74 at gmail.com)>  writes:
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>> Haris>  Anyhow, everything seems to work fine for now but the read
>>>>>>> Haris>  performance is a problem.
>>>>>>>
>>>>>>> Try mounting the volume with nfs and see if that improves things.
>>>>>>
>>>>>> --
>>>>>> --
>>>>>> Haris Zukanovic
>>>>>>
>>>>>> _______________________________________________
>>>>>> Gluster-users mailing list
>>>>>> Gluster-users at gluster.org (mailto:Gluster-users at gluster.org)
>>>>>> http://gluster.org/cgi-bin/mailman/listinfo/gluster-users
>>>>>
>>>>
>>>>
>>>> -- -- Haris Zukanovic
>>
>> -- -- Haris Zukanovic
>

-- 
--
Haris Zukanovic