Re: [Moosefs-users] Moosefs for logs

[Anh K. H. <ky...@vi...>]

On Fri, 20 Aug 2010 12:58:40 +0200
Michał Borychowski <mic...@ge...> wrote:

> You can easily use MooseFS to store any kind of content, including
> log files. Performance should not be affected. But it depends on
> the logging mechanism, if for writing every line the file is
> continuously opened, data appended and the file closed, for sure it
> is not perfect way to save logs. 

Here's my simple test results on AWS EC2 environment: A 'dd' command tries to write about 540MB to a MFS disk, the speed is very low (28MB/s). On the same server with native disk (instant disk of any AWS EC2 instance), the same command yields the speed around 140MB/s.

I don't know if I can deploy a database server on any MFS disk ... :(

/--------------------------------------------------------------
$ dd if=/dev/zero of=/tmp/mfs_c0/test bs=1024 count=524288

524288+0 records in
524288+0 records out
536870912 bytes (537 MB) copied, 18.9801 s, 28.3 MB/s

$ dd if=/dev/zero of=/tmp/test bs=1024 count=524288
524288+0 records in
524288+0 records out
536870912 bytes (537 MB) copied, 3.95007 s, 136 MB/s
\--------------------------------------------------------------


> And you have to remember about one thing. Different clients cannot
> write at the same moment to the same file located in MooseFS. So if
> you have several httpd servers, let them save the logs under
> different filenames (eg. access-192.168.0.1.log,
> access-192.168.0.2.log, etc.)


> 
> -----Original Message-----
> From: Anh K. Huynh [mailto:ky...@vi...] 
> Sent: Thursday, August 12, 2010 12:21 PM
> To: moo...@li...
> Subject: [Moosefs-users] Moosefs for logs
> 
> Hi,
> 
> I am a moosefs newbie. I am using EC2 instances and I intended to
> build a moosefs system to share EBS disks between instances.
> 
> My question is that: can I use moosefs for logs? My applications
> (web server, applications) need to write to logs files, but I don't
> know if there's any performance problem when logs are written to
> moosefs' disk.
> 
> Thank you for your helps,
> 
> Regards,
> 


-- 
Anh Ky Huynh