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  1. #1
    Join Date
    Dec 2011
    Posts
    7

    Unanswered: Informix 11.7 - Memory Leak - PHP PDO

    Good afternoon,

    my company implements PDO (PHP Data Objects) and IBM Informix Dynamic Server 11.7. For several weeks, the database server is regularly accessed from a CMS, loading between 5,000 and 10,000 images from BLOB fields every day. Since the application's launch, the databases crashes (does not respond to SQL queries, is not able to shut down via onmode -ucky etc.) about twice a week due to completely used up memory.

    The web server runs on a different machine than the database server. These are the specs:
    DB Server
    OS: OpenSuse 11.4 32-Bit
    DB: IBM Informix Dynamic Server 11.7
    RAM: 4 GB
    CPU: 2,2 GHz Dual Core

    WEB Server
    OS: Windows Server 2003
    Web server: Apache 2.2 (PHP 5.3.8)

    The persistent connection between the two servers is created via PDO, a part of PHP's standard to access databases. The PHP-extension "php_pdo.dll" and "php_ifx.dll" are laoded and work fine except for the memory leak.

    The problem occured also, when the DB server was another Windows Server 2003.

    The statement is pretty simple:
    Code:
    SELECT filename, requiredfile, zeitstempel
    FROM jobrequiredfiles
    WHERE jd_id = " . $_REQUEST['jd_id'] . ";";
    $_REQUEST['jd_id'] is an integer referring to the indexed integer jd_id, filename is a VARCHAR(255), zeitstempel is a DATETIME and requiredfile is a BYTE field.

    I appreciate any help. As far as I was told, this forum has a lot of capable users

  2. #2
    Join Date
    Sep 2011
    Location
    Pont l'Abbé, Brittany, France
    Posts
    381
    Provided Answers: 1
    Hi,


    did you take a look at the msgpath log file? are you sure the culprit is the Informix engine ? what about the application?

    We need more details.
    Can you please provide:
    the log file,
    onstat -a
    onconfig file
    some system monitoring showing process CPU and memory resource on the server.

    And we can start looking at something :-)

    Thanks
    Eric

  3. #3
    Join Date
    Dec 2011
    Posts
    7
    Hi Eric,

    here is a Link to a file which includes all the requested information.
    (The onconfig data are included in the onstat.txt)

    Information.zip

    Thanks for your help

  4. #4
    Join Date
    Sep 2011
    Location
    Pont l'Abbé, Brittany, France
    Posts
    381
    Provided Answers: 1
    hi,

    thansk for the info. can you please add the output of a
    vmstat 3 200

    at a time you feel the perf outage ?

    Give me some hours to check all this

    Thanks
    Eric

  5. #5
    Join Date
    Sep 2011
    Location
    Pont l'Abbé, Brittany, France
    Posts
    381
    Provided Answers: 1
    Hi again,

    I cannot see whether you have a memory leak, but it seems that you are very low in buffer pool, and a number of parameters should be increased.
    Also the SHM virtual size is disproportionated with what it should be. This can point to one or more
    bad query plans leading to total use of shm virtualsize.

    Also reset MAXPDQPRIORITY to 0, and check its eventual setting in env variables or application.
    you cannot use PDQPRIORITY with Innovator C

    First question: is this box exclusively an IDS Server?
    2nd: is there more than one instance of IDS on the machine
    3rd: is HDR active?

    After I have got the vmstat output, I can first provide some enhancement suggestions, then start real troubleshooting
    with guilty queries
    Last edited by begooden-it; 02-21-12 at 14:38.

  6. #6
    Join Date
    Sep 2011
    Location
    Pont l'Abbé, Brittany, France
    Posts
    381
    Provided Answers: 1
    Hi again,
    I have been hearing around that there is effectively a memory leak issue with the PHP driver. I'm gonna try to know more about it and figure out who can take part into the issue resolution.

    Keep in touch
    eric

  7. #7
    Join Date
    Feb 2014
    Posts
    3
    Hi

    did you ever figure out what it was?

    Thanks for your help

  8. #8
    Join Date
    Sep 2011
    Location
    Pont l'Abbé, Brittany, France
    Posts
    381
    Provided Answers: 1
    John,

    no information returned => no troubleshooting nor solution returned ...

    Something I certainly know is that the person I had identified to help will give a series of four free webcasts starting on March 18th. The subject is "Introduction to using PHP with Informix".
    learn more about the webcast here

    Those people are extremely knowleable on Informix and also on PHP, so this would be a good opportunity to talk with them.

    Do you have this problem too ? Is there any PMR created about it ?

    Cheers
    Eric
    Last edited by begooden-it; 02-27-14 at 10:08.

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