WebSphere Portal Server V4.1.3a and V4.1.4 ship custom version of WebSphere Application Server plug-in
 Technote (FAQ)
 
Problem
WebSphere® Portal Server shipped a custom version of the WebSphere Application Server plug-in that includes a cache. However, the cache frequently malfunctions.
 
Cause
All versions prior to WebSphere Portal Server V4.1.3a shipped a custom WebSphere Application Server plug-in that supports caching.

However, this plug-in was also prone to a "Red X" problem:
  • Images being served by WebSphere Portal Server, such as gif files, are supposed to be served more quickly through the cache.
  • However, the cache is failing to return valid images. As a result, browsers are displaying a red "X" in place of the image.
  • At the same time, the IBM® HTTP Server process will exhibit very high CPU utilization
  • The access_log should also report 304 (serving by cache) for the requested images.
 
Solution
When performing problem determination:
  • IBM HTTP Server trace and plug-in trace are inconclusive
  • Using dbx to attach to the IBM HTTP Server process with high CPU utilization shows this, or a similar stack:
    >$t1 run running 149599 k no pro esiCacheStoreObj
    esiCacheStoreObj(0x2027f158, 0x0) at 0x2008f34c
    storeResponseToCache(0x2039b5b8, 0x20429248) at 0x20088060
    esiResponseGet(0x2039b5b8, 0x1) at 0x2008a594
    esiHandleRequest(0x2ff224f0) at 0x20084334
    websphereHandleRequest(0x2ff225b0) at 0x2006da9c
    as_handler(0x203a24c0) at 0x2006430c
    ap_invoke_handler() at 0x100212bc
    process_request_internal() at 0x100455a4
    ap_process_request() at 0x10046728
    child_main() at 0x10002ae4
    make_child() at 0x1000249c
    perform_idle_server_maintenance() at 0x10002190
    standalone_main() at 0x10001b3c
    main() at 0x1000138c
    Solution:
    Uninstall the WebSphere Application Server plug-in, then use the WebSphere Application Server fix pack listed in Recommended Updates to reinstall the supported version of the WebSphere Application Server plug-in.

    Notes from WebSphere Portal Server Development:
    For those versions, if WebSphere Application Server was installed as part of the WebSphere Portal Server install through our installer, then the caching plug-in was installed as well, with the original library renamed with a .bak extension. So both the original and caching plug-in libraries are in the bin directory, but only one of them has the proper extension.

    If WebSphere Portal Server is installed on a machine that already had WebSphere Application Server installed on it, the caching plug-in WebSphere Application Server not installed, but could be installed manually if so desired, as the libraries are available from a documented place on the CD.

    For WebSphere Portal Server 4.1.3a and 4.1.4 it was decided NOT to install the plug-in by default but to make it available on the Web site as a technote.
 
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Plug-in
Operating system(s): HP-UX
Software version: 4.0
Software edition:
Reference #: 1080111
IBM Group: Software Group
Modified date: Jan 3, 2005