jd_g has asked for the wisdom of the Perl Monks concerning the following question:

I have a website I'm working on and every once in a while, a completely white page loads. I'm running mod_perl and Apache::DBI. While searching on google, I found some threads that point to memory problems, but a lot of those were PHP sites. Have any fellow perl users had a blank white page load periodically? I'm really not sure if this is a problem with perl, apache, mysql, or possibly the server itself. Any pointers would be appreciated.

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Re: White Screen of Death
by ikegami (Patriarch) on Sep 09, 2008 at 04:03 UTC
    What do the access and error logs say?
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      I see nothing unusual in any of the logs. I've checked the logs immediately after the white screen occurs and didn't see anything there.
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        You're asking for help on the matter, so I find it odd that you gave me your opinion instead of answering the question.

        Assuming the request was logged and you checked the status and it was 200, did you check the number of bytes sent?

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Re: White Screen of Death
by Anonymous Monk on Sep 09, 2008 at 06:22 UTC
    I'm really not sure if this is a problem with perl, apache, mysql, or possibly the server itself.

    Don't forget the network, the firewall, the client, and spyware/virus.

[reply]
      I'm running the site on two seperate servers on two seperate networks (dev and prod servers). The problem occurs on both. This leads me to believe the problem isn't related to any of those issues.
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        Here's an idea, modify your apache conf to emit Etag header (it should do it by default), and then modify your conf to log the Etag sent %...{Etag}o:, so when you get a blank white page, you can look at the http headers (Live HTTP Headers :: Firefox Add-ons), and then look for that Etag/ip combo in your apache logs.
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[d/l]
        This leads me to believe the problem isn't related to any of those issues.
        Why? Your diagnosis of the problem so far has been "completely white page loads". No mention of HTTP header, content ... for all you know both machines have the same (or similarly) faulty firewall, have the same virus, go through the same faulty node (or multiple faulty nodes) on the network... unless you can diagnose it using your web servers diagnostic facilities (log analysis), and your browser, you can't rule out anything :)
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Re: White Screen of Death
by grizzley (Chaplain) on Sep 09, 2008 at 08:26 UTC

    Separate the problem source:

    Try to load pure HTML page first on server with mod_perl and Apache::DBI disabled. Does it work?

    Now enable mod_perl and try to run simple perl script without DB. Does it work?

    Now you can ask more precise question :)

     Update: my apologies, didn't read carefully what is the problem about :/ Downvote it if you like, I want to stay at Monk level as long as possible :)
[reply]
      While jd_g didn't give us much to go on, he* did state that the problem only "periodically" occurs. So I don't see how your suggestions are going to accomplish much.

      ikigami got it right (of course); so many people resort to psychic debugging (or ask others to) when the system is happy to tell them what went wrong.

      * or she.


      sas
[reply]
        Sorry for not giving you much to go on. I was hoping someone out there had experienced this problem before. From my experience, a blank white screen is not very common. I've tried to debug, but the problem never occurs when I want it to. It seems to occur randomly. The last thing I expect is to have other's do the dirty work for me. I debug all the time. Before posting, I searched perlmonks as well as many other sites. I've checked the log files on the server. I've checked the mysql processes when the problem occured. I probably should have mentioned this, but like I previosly said... I was hoping someone out there had experienced the blank white page before and could give some tips.
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