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From "pradeep kumar" <>
Subject Re: High CPU utilization on using Apache as a reverse proxy
Date Fri, 18 Aug 2006 16:04:10 GMT
Hi Jon,

Sorry if i mislead you into assuming that I am using Solaris. I am using
HP-UX 11iv2. Is HP-UX also affected? In this case also SSL is being used.


On 8/17/06, Jon Snow <> wrote:
> Pradeep,
> I can't remember if I posted the results of the SSL issue and high CPU
> usage.
> We tracked it to a bug in the solaris driver for the Sun daughter card,
> some
> mutex issue if my memory serves me correctly. Sun confirmed and issued a
> patch a while ago. As discussed in the quoted post I did not believe it
> was
> an apache issue for the SSL but I showed dumps for a corresponding write
> issue with a forward proxy in an early anticipation it may be related.
> This forward proxy problem I had sounds similar to your issue where apache
> appears not to test a return value for a write but it did not utilise
> large
> CPU. Currently I run 2.2.2 and have observed the same write problem as I
> did
> with 2.0.53. One main issue I have with this is the download continues
> while
> the write fails so effectively the active connection is not in sound
> communication with the passive.
> I put the huge memory usage down to the byte range bug as these processes
> were
> nearly always streaming or FTPing large files. I have not seen this memory
> usage with the version I am running even when I see the write problem.
> To clarify your issue are you running SSL and if so are you using hardware
> crypto? I assume you are using solaris, is it patched for crypto re: above
> and what version of solaris are you using?
> Regards,
> Jon
> On Tuesday 15 August 2006 00:47, pradeep kumar wrote:
> > Hi,
> >
> > I notice there is a 100% CPU utilization which spikes for sometime and
> then
> > goes back to normalcy when Apache is used a reverse proxy. I noticed a
> mail
> > thread which seems to be a similar problem
> >
> >
> >
> >
> > One thread of one of the child processes hangs, calling poll() and
> writev()
> > system calls so frequently that it causes 100% CPU util. The thread is
> > trying to writev() to a socked which is in CLOSE_WAIT The child process
> > ends after time defined by ndd parameter tcp_keepalive_interval and the
> > same service time can be seen in access_log. The problem disappears
> then.
> >
> > Regards,
> >
> > Pradeep

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