Direct procedure call cached?

Question

Hi,
running Listener 2.0.2.133.14.47 under WLS.
I have asked a similar question before but was not given a good answer, https://forums.oracle.com/thread/2292910
I have a packaged procedure that prints a web page using htp.p().
Sometimes (I cannot reproduce at will) the procedure's result is not updated when I refresh the page in the browser.
That is, pressing F5 (or Ctrl+F5) gives an old result.
I wrote and granted to apex_public_user this package:
CREATE OR REPLACE PACKAGE BODY callpack AS
PROCEDURE calltest (param varchar2 default null) IS
BEGIN
  htp.p('<div>You gave me "'||nvl(param,'&lt;null&gt;')||'". The time is '||to_char(sysdate,'HH24:MI:SS')||'</div>');
  for i in 1..1000 loop
    htp.p('<div>1000 rows of meaningless content</div>');
  end loop;
END calltest;
END callpack;
I called this from my browser like this: http://server/apex/my_schema.callpack.calltest
Initially I got a new time with every update (F5). After leaving it for a few minutes and trying again it got "stuck". Every refresh now gives me the same response.
The response header for this apparently cached page looks like this
Accept-Ranges    bytes
Age    1250
Connection    Keep-Alive
Content-Encoding    gzip
Content-Length    423
Content-Type    text/html; charset=UTF-8
Date    Thu, 07 Nov 2013 10:20:22 GMT
Vary    Accept-Encoding
X-ORACLE-DMS-ECID    632c140cd74ad62b:281ea775:1410befd01e:-8000-0000000000d03396
X-Powered-By    Servlet/2.5 JSP/2.1
I have also compiled and granted the above packaged procedure as standalone. This has (yet) not been cached. The response headers there:
Connection    Keep-Alive
Content-Length    49
Content-Type    text/html; charset=UTF-8
Date    Thu, 07 Nov 2013 10:20:08 GMT
X-ORACLE-DMS-ECID    632c140cd74ad62b:281ea775:1410befd01e:-8000-0000000000d04f52
X-Powered-By    Servlet/2.5 JSP/2.1
Besides from restarting the server, the only way I know of to make the listener actually call the procedure when caching is to change case in the url.
So if http://server/apex/my_schema.callpack.calltest is cached, I can get a new page using http://server/apex/My_schema.callpack.calltest
Or I can add a parameter (?param=X) that I change when I want new content.
Has anyone noticed this?
Is there some caching mechanism in the listener (when doing direct pl/sql-calls)? Or is it WebLogic doing something... sometimes...
Kind regards
Tomas Albinsson

Answer 1

TomasAlbinsson wrote:
Hi,
running Listener 2.0.2.133.14.47 under WLS.
The response header for this apparently cached page looks like this
Accept-Ranges    bytes 
Age    1250 
Connection    Keep-Alive 
Content-Encoding    gzip 
Content-Length    423 
Content-Type    text/html; charset=UTF-8 
Date    Thu, 07 Nov 2013 10:20:22 GMT 
Vary    Accept-Encoding 
X-ORACLE-DMS-ECID    632c140cd74ad62b:281ea775:1410befd01e:-8000-0000000000d03396 
X-Powered-By    Servlet/2.5 JSP/2.1 
I have also compiled and granted the above packaged procedure as standalone. This has (yet) not been cached. The response headers there:
Connection    Keep-Alive 
Content-Length    49 
Content-Type    text/html; charset=UTF-8 
Date    Thu, 07 Nov 2013 10:20:08 GMT 
X-ORACLE-DMS-ECID    632c140cd74ad62b:281ea775:1410befd01e:-8000-0000000000d04f52 
X-Powered-By    Servlet/2.5 JSP/2.1 
The first set of headers seem to indicate that part of your network flow recognizes that the content that it is returning to you was originally generated 1250 seconds ago - so something is caching.
Doing the same test on my Glassfish/Listener combination produces the following response heading:
X-Powered-By: Servlet/3.0 JSP/2.2 (Oracle GlassFish Server 3.1.2.2 Java/Oracle Corporation/1.7)
Server: Oracle GlassFish Server 3.1.2.2
Content-Type: text/html;charset=UTF-8
Content-Length: 63
Date: Wed, 20 Nov 2013 12:33:45 GMT
200 OK
This might indicate that the caching is occurring within your Weblogic setup or some other cache in the network?