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Re: New LVS installation - wierd problems

To: <lvs-users@xxxxxxxxxxxxxxxxxxxxxx>
Subject: Re: New LVS installation - wierd problems
From: Nate Stone <nate@xxxxxxxxxxxx>
Date: Tue, 21 Aug 2001 16:54:23 -0400 (EDT)
Thanks for the reply.
>
>       It seems you have problems with your real server OS. May be
> you can tell us the exact versions of the real server (if Linux) and
> of the Apache. But that seems as incorrect process state management
> in the kernel. What shows vmstat on the real server? Full CPU usage?
> Any additional patches applied on the real servers?

The real servers are Redhat 7.1 running kernel 2.4.5 with the ipvs and
netfilter patches (and any others that came with the IPVS distro).   This
could, of course, be the problem - I am aware that IPVS is still in
development for kernel 2.4.5.  Maybe I need to downgrade?

The real server is completely unloaded when this problem is going on
(processor wise).  vmstat shows 94% idle for processor and a bunch of
uninterruptible sleep processes (800).  Our disk swap is rather high
(200-400 MB) and we're not sure if shared memory is working properly
(which could be a dramatic effect since Apache relies heavily on shared -
apparently they turned off the shared memory calculation in kernels 2.4.x
which really is killing our ability to optimize our memory configuration).
We plan to add more ram this week (we have 512mb per server on Athlon
933mhz processors).  The problem really looks like simple NFS I/O wait
which is a problem because we will have to upgrade our drive system if
that's it - I'm optimizing NFS right now, but I'm not getting much
improvement.

>       Your real server should be ready for everything: attacks,
> incorrect packets, etc. IMO, you can achieve the same D states even
> without using LVS. The problem can't be in the director.

I agree that the problem can occur any number of ways and was really just
curious if anyone had seen similar problems in other LVS implementations.
 I think it is probably just disk/nfs i/o which may just be a lack of
hardware.

Thanks for your help.  Please let me know if you have any other
suggestions.

Later,
Nate

>


> > Thanks a bunch.
> >
> > -Nate
> > Nate Stone
> > CTO
> > keenspot.com
>
> Regards
>
> --
> Julian Anastasov <ja@xxxxxx>
>
>
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