[Linux-cluster] WebFarm using RedHat cluster suite ?

[Marc Grimme]

On Thursday 19 January 2006 17:43, FM wrote:
> First, Thank you all for the great input !
> Here is more output about our sites :
> Some static HTML web site. Sites are generated in Lan and then rsync to
> DMZ. And other with mod_perl + Postgresql Database (local)
Don't use postgres clustered(parallel with multiple writer nodes, HA should 
not be a problem) on gfs. That is not supposed to work. As far as I know. You 
would need a dbms that supports parallel clustering itself. Like i.e. Oracle 
9iRAC.
> One of our most visited site (static html) is using nealy 200 GB of
> bandwidth / month
> and have 545368 hists a day.
> For decembre 2005 stats  :
> http://stats.lexum.umontreal.ca/awstats.pl?month=12&year=2005&output=main&c
>onfig=www.canlii.org&lang=en&framename=index
>
> Now we are using dual Xeon (2 Ghz), with 2,5 GB of RAM. with RAID 5 SCSI
> 10KRPM
> Network is GB
> Budget is 200K CA$
Ok. You are having 500000 hit/day. One question would be how many I/Os does a 
hit issue. The other question is, is that the upper bound or do you expect it 
to grow, so that the infrastructure will have to grow in parallel. You should 
really be picky about the storage-infrastructure (includes storage system and 
locking network). Separate storage and locking network. Under normal 
circumstances 500000hits/day should not be a problem. But if you are right 
now using SCSI Disks stay with SCSI or FC-Disks they are way much faster and 
relyable then SATA. The more and faster Disks you use the more I/Os you will 
get. Besides for 200k CA$ you should also get a FC-Infrastructure and 
Storage. 
Also think about consolidating all data (even the os, share the root fs of the 
servers) on to the storage system. It saves you loads of management (scales 
within small amount of time) and disks in the servers. And you can easily 
replace a faulty server by pulling it out and powering a new one back on. We 
have made quite good experiences at webfarms with that concept. 
Check back a http://www.open-sharedroot.org/. We will have a howto for 
building up such a sharedroot within the next week.

Hope that helps
Regards Marc.
>
> Thanks again
>
> Eric Anderson wrote:
> > Marc Grimme wrote:
> >> Hello,
> >> I think the best way to tell what storage or infrastructure would be
> >> the best is to know more about your current setup and what issues
> >> with that you want to get ahead of.
> >> For example: if you really think about using iscsi, I don't think
> >> that SCSI or SATA drives make a big difference - depending on how
> >> many drives you use. But if all webservers currently have locally
> >> attached disk drives you want scale too linar with exchanging and
> >> IDE/parallel-SCSI Bus with an network topology using Ethernet. But my
> >> opinion is: if you have a lot of I/Os make yourself mostly
> >> independent from the latency of an ethernet and rethink about using
> >> Fibre-Channel with GFS.
> >
> > Honestly, ethernet latencies (especially on gigabit ethernet) are
> > lower than fiber channel latencies, so this statement doesn't really
> > hold up.
> > If you want very fast speeds, get an iSCSI array, populate it with 15k
> > RPM scsi disks with big caches, max the cache out on the array, and
> > set it up for a RAID0+1 (or RAID10 depending on the implementor).  If
> > you want fast speed, but not a big price, you can notch down to 10K
> > scsi disks, or use 15k scsi disks and a raid 5, etc, and keep notching
> > down until it fits your budget and needs.
> > I agree here though that we really need to know a few things:
> >
> > - what kind of traffic is this?
> > - size of the files most commonly used
> > - total data size (how much space you need)
> > - budget
> > - demands (availability/performance/etc)
> >
> > Eric
> >
> >> But the best advices could be made if you make your current setup and
> >> the things you want to achieve more clearly.
> >>
> >> Regards Marc.
> >>
> >> On Wednesday 18 January 2006 22:01, FM wrote:
> >>> Thanks for the reply,
> >>> I read about SATA storage but we sync from lan to dmz, so there is lots
> >>> of r/w.
> >>>
> >>> Michael Will wrote:
> >>>> I am surprised you use SCSI drives on the storage if
> >>>> you are price sensitive, usually SATA is the better
> >>>> bang for the buck unless you are doing databases with
> >>>> lots of small read and writes.
> >>>>
> >>>> Michael
> >>>>
> >>>> -----Original Message-----
> >>>> From: linux-cluster-bounces at redhat.com
> >>>> [mailto:linux-cluster-bounces at redhat.com] On Behalf Of FM
> >>>> Sent: Wednesday, January 18, 2006 12:34 PM
> >>>> To: Redhat Cluster
> >>>> Subject: [Linux-cluster] WebFarm using RedHat cluster suite ?
> >>>>
> >>>> Hello everybody,
> >>>>
> >>>> Is redhat cluster suite (RHEL 4 ) a good candidate for a webfarm ?
> >>>> My setup would be : several servers (1U AMd dual core) connected to
> >>>> iscsi storage array.
> >>>>
> >>>> Is Iscsi a good choice (SAN prices are too high for us) for hardware ?
> >>>> Our network is GB.
> >>>> We will have SCSI 10KRPM + read and write cache on the SCSI card +
> >>>> RAID5
> >>>> thanks !
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>> --
> >>>> Linux-cluster mailing list
> >>>> Linux-cluster at redhat.com
> >>>> https://www.redhat.com/mailman/listinfo/linux-cluster
> >>>>
> >>>> --
> >>>> Linux-cluster mailing list
> >>>> Linux-cluster at redhat.com
> >>>> https://www.redhat.com/mailman/listinfo/linux-cluster
> >>>
> >>> --
> >>> Linux-cluster mailing list
> >>> Linux-cluster at redhat.com
> >>> https://www.redhat.com/mailman/listinfo/linux-cluster
>
> --
> Linux-cluster mailing list
> Linux-cluster at redhat.com
> https://www.redhat.com/mailman/listinfo/linux-cluster

-- 
Gruss / Regards,

Marc Grimme
Phone: +49-89 121 409-54
http://www.atix.de/

**
ATIX - Ges. fuer Informationstechnologie und Consulting mbH
Einsteinstr. 10 - 85716 Unterschleissheim - Germany