Re: [Moosefs-users] mfs mount generates high trafic from chunks

[Michał B. <mic...@ge...>]

Hi Eduard!

So... From the number of 'getattr', 'open' i 'read' operations we conclude
that there are about 4500 files read in one minute. Given three chunkservers
it takes 1500 reads per minute per one server, which is 25 reads per second
on one server. The system shows there are 24MB read per second which would
mean an average file size of about 950kB and transfer about 190Mb/s.

On the other hand there are about 1 160 000 files which with an average file
size of 950kB would occupy about 1 TB. From the Info tab we see the system
has 14 TB of space with 13 TB free - everything sums up properly.

So the question would rather be - why the server requests so many reads
though it does not send that amount of data? Please check your webserver and
its configuration. What webserver do you use? Thereotically none webserver
should make unnecessary reads. You can try connecting to the webserver by a
tool like "strace" and see what operations are made.


Kind regards
Michał Borychowski 
MooseFS Support Manager
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Gemius S.A.
ul. Wołoska 7, 02-672 Warszawa
Budynek MARS, klatka D
Tel.: +4822 874-41-00
Fax : +4822 874-41-01


-----Original Message-----
From: Eduard Iacoboaia [mailto:edu...@di...] 
Sent: Friday, January 22, 2010 3:26 PM
To: moo...@li...
Subject: Re: [Moosefs-users] mfs mount generates high trafic from chunks

There are 2 chunks, goal 2 on all files, one active mount (the
webserver): 3 virtual machines, each hosted on separate servers, nothing
else on those servers. The master, metaloger and mfscgi are 3 virtual
machines hosted on a 4th server. I attached some screenshots. I noticed the
getattr chart resembles a lot those from traffic in chunk servers.

--
Eduard

Michał Borychowski wrote:
> Don't you have any additional replications between chunkservers? Does 
> the webserver and one of chunkservers use the same machine?
>
>
> Kind regards
> Michał Borychowski
> MooseFS Support Manager
>
>
>
> -----Original Message-----
> From: Eduard Iacoboaia [mailto:edu...@di...]
> Sent: Friday, January 22, 2010 12:31 PM
> To: moo...@li...
> Subject: Re: [Moosefs-users] mfs mount generates high trafic from 
> chunks
>
> Hi.
>
> This is the traffic incoming on port 9422 in the mount server:
>  --------------------------------------------------------
>  |  Rate  |              Average for                    |
>  --------------------------------------------------------
>  |########|    3 sec     |    15 sec     |    30 sec    |
>  --------------------------------------------------------
>  |  bits  |    154.2M    |     142.4M    |     145.7M   |
>  |  pkts  |     13.1K    |      12.1K    |      12.3K   |
>  --------------------------------------------------------
>
>
> This is the outgoing port 80 from the same server:
>  --------------------------------------------------------
>  |  Rate  |              Average for                    |
>  --------------------------------------------------------
>  |########|    3 sec     |    15 sec     |    30 sec    |
>  --------------------------------------------------------
>  |  bits  |      1.6M    |       1.2M    |       1.2M   |
>  |  pkts  |      171     |       129     |       127    |
>  --------------------------------------------------------
>
>
> I also attached a screenshot. If it's not what you needed, please let 
> me know.
>
> Thanks,
> --
> Eduard
>
> Michał Borychowski wrote:
>   
>> And what do you have on graphs from chunkservers? Could you send us 
>> the screenshots from the cgi monitor?
>>
>> Is there really 35-70Mb transfer between mfsmount and chunkservers?
>>
>>
>> Kind regards
>> Michal
>>
>> -----Original Message-----
>> From: Eduard Iacoboaia [mailto:edu...@di...]
>> Sent: Thursday, January 21, 2010 11:29 AM
>> To: moo...@li...
>> Subject: [Moosefs-users] mfs mount generates high trafic from chunks
>>
>> Hi.
>>
>> I have a webserver that has the files (~1.1mil files and 280gb) 
>> mounted over mfs 1.6.11. Although the server generates about 2-3mbit 
>> of http trafic, it retrieves from chunk servers between 35 and 70mbit 
>> (5sec average). The mount has:
>>
>> mfscachefiles,mfsattrcacheto=10,mfsentrycacheto=10,mfsdirentrycacheto
>> =
>> 20
>>
>> Is there anything I can do to lower the amount of traffic from chunks?
>>
>> Thanks,
>> --
>> Eduard
>>
>>
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>
>