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  • Re: Error 500.13 (Server too busy) with many sites on one machine

    Apr 04, 2008 02:33 AM|ganeshanekar|LINK

    There are 4 main reasons in IIS 6 why the Server Too Busy error will be displayed
    in response to an ASP request:

    1) The application pool's ASP queue is full (or in other words, the metabase value
    ASPRequestQueueMax has been reached)

    2) A new App Pool cannot be spawned due to OS process limits (or in other words, we
    have reached the maximum number of concurrently running application pools.

    3) An ASP request has been in the ASP queue longer than the value set for the
    metabase key ASPQueueTimeout

    4) We have run out of desktop heap.

    I would take a Hang dump using DebugDiag tool and see what is happening and why the requests are taking long time to execute. Normally this would turn out to be code issue.

    Important : Are you running these sites in Seperate app pools or 1 single app pool? If they are in single pool, then try seperating them in different app pool.

    Another thing is system resources, are you running many products like SQL/Exchange on the same box as IIS and also are they any third party apps, many processes running on this box? If there are many processes running it might cause desktop heap issue. you could use Dheapmonitor and see if there is enough desktop heap available to spwan a new process.

    AFAIK, I have seen more than 50000 sites running on 1 single IIS6.0 box and running Classic ASP and ASP.NET..you are not there yet.


    ~ Ganesh

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