Run heavy loaded web farm using NFS storage

[Georgios Magklaras]

On 12/09/2010 01:49 PM, Dusan Djordjevic wrote:
> Hi all,
>
> Since we would need to change some config on web farm layer, I
> consider moving it to Red Hat 6. Architecture that I do have in mind
> is:
>
> Load Balancer
> 4 x web server (Red Hat 6, Apache out of box)
> NetApp storage mounted via NFS
>
> Site serves mainly static content and connects to Tomcat app servers.
> Sometimes it can have thousands of simultaneous connections.
>
> I do not have any recent experience with NFS storage, especially with
> Red Hat 6.
>
> Any advices for or against this solution ?
> Performance wise, is it going to work properly ?
> Any other things I should think about before I do this ?
>
> Thanks in advance.
>
> Dusan
>
The most notable difference in terms of NFS in RHEL 6 is that of NFS 
version 4. NFSv4 is used now by default amongst RHEL boxes that support 
it and in doing so it offers some advantages over the previous default (v3).

Apart from the lack of rpcbind, which could slow things down, the most 
important benefit is FS-Cache (Solaris folk use the cachefs equivalent).

http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/fscachenfs.html

FS-Cache benefits vary and are scenario dependent (there are cases where 
I have seen it to slow down things). But on a typical read-only scenario 
over dedicated Gigabit Ethernet links (Jumbo frames on)between the 
Apache server and the NFS box (RHEL 6) gave us a 20%-30% boost. So, for 
our platform, we find that RHEL6 (web)<->RHEL 6(NFS) is faster than RHEL 
5(web)<->Netapp (NFS).

Your case might be different.

GM

-- 
-- 
George Magklaras
Senior Systems Engineer/IT Manager
Biotek Center, University of Oslo
EMBnet TMPC Chair

http://folk.uio.no/georgios

Tel: +47 22840535