[Gluster-users] Slow file open

[Pavan]

On Tuesday 03 May 2011 09:52 PM, Mohit Anchlia wrote:
> Yes I can reproduce everytime I run my tests.
> This happens always. Not sure if you call 50 threads writing files to
> 4 X 2 servers high load.

What version of GlusterFS are you using?

What application is seeing the slow open? How are you measuring the open 
latency?

> Application see slower response time and low throughput. For eg: you
> would expect at least 80MB/s on 1GigE with 4 X 2 when each cluster
> with "dd" can do 130 MB/s. But because of this I see only 20-30MB/s.

I am not very sure I would dive right away to that conclusion. Lets 
first measure what is taking long to complete.

Pavan

>
> On Mon, May 2, 2011 at 9:36 PM, Pavan<tcp at gluster.com>  wrote:
>> On Sunday 01 May 2011 03:59 AM, Mohit Anchlia wrote:
>>>
>>> Can someone from dev help with this? Is it overhead in fuse or
>>> something else? I am seeing file open operation taking anywhere
>>> between 30ms - 2 secs and this is killing the performance.
>>
>> * Can you recreate this problem on your setup at will?
>> * Does the delay happen when you are opening any file or is it under certain
>> scenarios - like excessive load? What is application that is facing this
>> hang?
>>
>> To start with, check if the open on the backend (on a single brick) is
>> taking long, with the same application.
>>
>> Pavan
>>
>>>
>>> On Fri, Apr 29, 2011 at 4:27 PM, Mohit Anchlia<mohitanchlia at gmail.com>
>>>   wrote:
>>>>
>>>> I am not seeing optimal performance out of my 4 X 2 cluster node. When
>>>> I look at thread state that's writing files I see most of them are
>>>> waiting on file open.
>>>>
>>>> Does anyone know how to further troubleshoot this issue?
>>>>
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>>
>>