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2 Replies Latest reply: Mar 7, 2011 8:06 PM by 438396 RSS

WebCache not caching files

369773 Newbie
Currently Being Moderated
Hi all,

i have application server 10g (9.0.4) with serveral applications deployed in multiple OC4J instances.

There is a rule that instruct webcache to cache all image files (gif,jpg,png,etc) this rule is working good except for one application.

In webcache admin -> popular requests (not cached) i can see the reason these files are not cached.

Webcache matches the rule for caching images but , it "chooses" not to cache with the following reason: BY_SURROGATE_CONTROL_HEADER

Reading from the webcache admin manual i get litte info:

Cache Reason: The reason that the object is cached or not cached. Possible values are:

o BY_SURROGATE_CONTROL_HEADER: Cached or not cached because of information in the Surrogate-Control response header.

I just don't understand these Surrogate-Control response header.

I have reported this issue to application developer that claim they have no code enabling/disabling the caching of pages.

Can you give me some clarification in this issue ? what is surrogate-control header ? if this surrogate control is generated by application , how can i detect it ? how can i handle it ?

My Environment

Oracle application server 10g (9.0.4) on windows 2003 server
Application built with BC4J framework

Best Regards

Rui Madaleno
  • 1. Re: WebCache not caching files
    369773 Newbie
    Currently Being Moderated
    Found the problem !

    The application deployed is protected with SSO, and SSO ads a control header to the pages that is protecting so it don't get cached.

    the "workaround" is modify the mod_osso.conf file, edit the <location> tag to include the
    OssoSendCacheHeaders directive.


    <LocationMatch "/wfat/img">
    OssoSendCacheHeaders off

    Best Regards

    Rui Madaleno
  • 2. Re: WebCache not caching files
    438396 Newbie
    Currently Being Moderated
    Our remote users have complained for months about slow application response. By making this one, simple change to mod_osso.conf, the application performance has increased dramatically...

    Good Job!

    So... what other unfortunate defaults are there that I don't know about? (already found out that leaving "shared_servers" at "1" is a really bad idea.)