Re: Ats.: [squid-users] Re: Squid floods and kills router

On Sunday 22 June 2003 19.40, Andrius Kriučkovas wrote:
> Hi,
>
> > There is an open bug report about issues with delay pools,
> > claiming that delay pools is not working at all in 2.5.STABLE3
> > IIRC. I have
>
> I've looked for it in squid-cache.org Bugzilla database, but unable
> to find anything related to IRC and delay pools.
>
> Closest match I think is, but nothing like my case:
> http://www.squid-cache.org/bugs/show_bug.cgi?id=670

Which is what I remembered. (IIRC: If I Recall Correcly)

> I've tested delay pools on direct connection SquidServer<>Client
> (only fast swicth between, no router) - client is able to get page,
> but trafic is the same - very high number of 1 byte packets.
>
> Client machine - P4 @ 2.4 Ghz, 512 RAM, 100 Mbps 3COM NIC.
> Server - much the same HW.
>
> Result - CPU usage when using delay pools peaks from 30% to average
> 80-90%. rate measured with snifer - ~20000 packets/sec. In such
> case I do not wonder why my small router is out of CPU power to
> survive!

Sounds like this could be the cause of Bug #670.

> I understand that clearly. The problem is that fixing the router
> this time is the harder way to go, because it is a part of
> infrastructure, while Squid as of today - is not.

Fixing the router is not about correting this issue, but correcting
the fact that this issue causes your router to crash and require a
reboot to recover.

> So, now I wonder, if:
>
> 1. My case is usual Squid behaivior.
> A. If so - can it be changed to send larger, but fewer delayed
> packets?

Delay pools are not supposed to give storms of small packets. Instead
they are supposed to give delayed larger packets up to te byte rate
specified in the pool.

> 2. It is mis-configuration in my config?

Not likely.

> 3. Squid NT port is broken / mis-implemented in some way.

It may be a NT port issue, or maybe a generic Squid-2.5.STABLE3 issue.
I do not know which yet. Bug #670 seems to suggest it is a generic
Squid-2.5.STABLE3 issue if the cause is the same, but Bug #670 is
less verbose on the detailed symptoms so I do not know.

A quick test on Linux seems to indicate delay pools works like
expected however. Created a class 1 pool with parameter 1000/1000,
and I have a single 1000 byte packets sent to the client once per
second.

I think your problem is probably different from that of Bug #670.

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