Ojsp cache tags

Hi,
itÂ´d like to know how to use the ojsp-cache-Tags with Oracle Reports. These tags are mentioned in some documentations but there is nowhere an example how to use that tags.
thanks in advance

hello,
they should be documented in the JSP area here on OTN. they are not directly related to Oracle Reports, but an extension that oracle provides to the JSP standard.
thanks,
ph.

Similar Messages

Making sure setting ojsp-init tags-reuse from orion-web.xml is used

I'm facing a problem with the following setting in my application's orion-web.xml:
<ojsp-init tags-reuse="compiletime-with-release"/>
previously, we had this setting in global-web-application.xml, but we would like to specify it per application, to get rid of the OC4J post-installation step to manually add the following lines:
<init-param>
<param-name>tags_reuse_default</param-name>
<param-value>compiletime_with_release</param-value>
</init-param>
However, the latter works, and the former doesn't seem to have any effect whatsoever. But as far as I can see, the orion-web.xml is correctly following the XSD:
<?xml version="1.0"?>
<orion-web-app
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="http://xmlns.oracle.com/oracleas/schema/orion-web-10_0.xsd"      deployment-version="10.1.3.3.0"
     deployment-time="1198148775354"
     jsp-cache-directory="./persistence"
     jsp-cache-tlds="standard"
     jsp-taglib-locations=""
     temporary-directory="./temp"
     servlet-webdir="/servlet/"
     context-root="/messagecontrol"
schema-major-version="10" schema-minor-version="0" >
     
     <ojsp-init tags-reuse="compiletime-with-release"/>
</orion-web-app>
http://www.oracle.com/technology/oracleas/schema/orion-web-10_0.xsd
Am I missing something here? Do we need to do something specific to make sure the ojsp-init values are actually used? The documentation seems to indicate that the two settings are equivalent:
http://download.oracle.com/docs/cd/B32110_01/web.1013/b28961/devconfig.htm#BHCFICDA
Any help would be appreciated.
Jaap

Update:
In the meantime I've logged a SR for this. The settings "none" and "compiletime" do work and behave the same as their global-web-application.xml counterparts. It's just the "compiletime-with-release" that does not work as expected.

Synchronization bug in Cache Tag

We have encountered what we believe to be a serious synchronization bug in
          the Cache Tag implementation of WL 5.1.0 SP6, under Windows NT 4, using
          HotSpot Server VM 2.0. (It also happens when we use the classic VM with the
          "-classic" option.) It seems like some kind of problem with a global lock
          on the underlying cache. The problem manifests when two or more browser
          clients attempt to access a JSP with a cache tag, where the cached value has
          not yet been computed. If the system is busy computing the contents of the
          tag when the second request arrives, no result is ever returned to either
          client and no further cache tag values (even on unrelated pages) are
          returned until the server is restarted.
          Here is a very simple tag class that illustrates the problem. It simply
          pauses five seconds and then prints the end time.
          package com.splwg.web.services;
          import java.io.IOException;
          import javax.servlet.jsp.JspException;
          import javax.servlet.jsp.JspWriter;
          import javax.servlet.jsp.PageContext;
          import javax.servlet.jsp.tagext.TagSupport;
          public class TestTag extends TagSupport {
          public int doStartTag() throws JspException {
          // Pause 5 seconds
          long start = System.currentTimeMillis();
          long end = start + 5000;
          while (System.currentTimeMillis() < end) {
          JspWriter out = pageContext.getOut();
          try {
          out.print("Done - " + end);
          } catch (IOException e) {
          return SKIP_BODY;
          Here is a JSP page to drive it:
          <%@ taglib uri="taglib.tld" prefix="wl"%>
          <%@ taglib uri="test.tld" prefix="test"%>
          <html><head><title>Test tag</title></head>
          <body>
          <wl:cache timeout="20s">
          <test:test/>
          </wl:cache>
          </body>
          </html>
          And here is the test.tld file:
          <?xml version="1.0" encoding="ISO-8859-1" ?>
          <!DOCTYPE taglib
          PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.1//EN"
          "http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd">
          <taglib>
          <tlibversion>1.0</tlibversion>
          <jspversion>1.1</jspversion>
          <shortname>test</shortname>
          <tag>
          <name>test</name>
          <tagclass>com.splwg.web.services.TestTag</tagclass>
          </tag>
          </taglib>
          To manifest the problem, start a fresh instance of WebLogic and have two
          browsers (nearly) simultaneously attempt to access the page. The server
          never returns to either browser, and no other page that contains a cache tag
          will return. However, WebLogic is not dead; static pages or JSP files
          without cache tags still work.
          The problem will not manifest once the cache is safely loaded, e.g. by
          having only one client make the initial access (in this case the second
          client cannot attempt to access the JSP for five seconds). Further, we
          observe that once the cache value has gone stale, the first new request
          forces a re-read, but other concurrent requests receive the previously
          cached value. Clearly this technique doesn't work when the cached value has
          not yet been populated, such as when the server has just been started.
          Has anyone else seen this problem?
          Felix Hack
          [email protected]


Before you put in that effort...
This is experimental so do it with a copy of the project.
With the copy project closed, delete the eHlpDhtm.js and the
projectname.pss file.
Copy the eHlpDhtm.js from the new project you created. Open
the project the the pss will get rebuilt.
No scientific reason for doing that, just something that is
minimal effort and worth a try.
If it fails, go back to the recreation plan! Do let us know
if it does work.

API to flush cache tags?

We plan to use the new cache tag supplied with 5.1 SP6. We've been asked
          whether there is a programmatic way to flush the cache. Has anyone found a
          way to do this? In lieu of such a facility we plan to set the cache to
          timeout more often than we might otherwise.
          Felix Hack
          [email protected]


Did you try this:
          <jsp:include page="a.jsp?_cache_refresh=true"/>
          <jsp:include page="b.jsp"/>
          w cheng <[email protected]> wrote:
          > However is there a way to just force refresh an included
          > JSP ? The following is sample:
          > test.jsp
          > --------
          > .....
          > <jsp:include page=a.jsp>
          > .....
          > <jsp:include page=b.jsp>
          > .....
          > Inside a.jsp and b.jsp, there are wl:cache tags. My question
          > is how to force refresh the cache content of a.jsp but not
          > affecting cache inside b.jsp ?
          > Thanks!
          > Dimitri Rakitine <[email protected]> wrote:
          >>I think it works similarly to 'key' cachetag parameter - it searches
          >>parameter,...,application,session for cacherefresh=true and invalidates
          >>the
          >>cache if it finds it, for example:
          >>
          >>test.jsp:
          >>
          >><%@ taglib uri="taglib.tld" prefix="wl" %>
          >><HTML>
          >><BODY>
          >>Current time is:
          >><wl:cache timeout="2h">
          >><%= System.currentTimeMillis() %>
          >></wl:cache>
          >></BODY>
          >></HTML>
          >>
          >>and http://localhost:7001/test.jsp will show cached time and you can
          >>force refresh by calling it like:
          >>http://localhost:7001/test.jsp?_cache_refresh=true
          >>
          >>I guess in a similar way you can put cacherefresh=true to the request
          >>parameter, attribute, session or servlet context.
          >>
          >>Felix Hack <[email protected]> wrote:
          >>> Could someone provide an example of flushing the cached data for a
          >>cache tag
          >>> for an entire application? I don't understand what kind of entity
          >>> cacherefresh is (see below). Here is the relevant extract from the
          >>WL
          >>> 5.1documents:
          >>
          >>> "You can force the refresh of a cache by setting _cache_refresh to
          >>true in
          >>> the scope that you want affected. If you want all caches to always
          >>refresh,
          >>> put it in the application scope. If you want all the caches for a user
          >>to be
          >>> refreshed, set it in the session scope. If you want all the caches
          >>in the
          >>> current request to be refreshed set it as a parameter or in the request."
          >>
          >>> --
          >>> Felix Hack
          >>> [email protected]
          >>
          >>Dimitri
          Dimitri

Cache tag exceptions and deadlocks

          Weblogic 6.1 sp2 on W2K and Solaris
          If an un-caught Exception is produced from code with-in a cache tag, then the
          cache for that page will become locked until server restart
          This can be tested by throwing an Execption and displaying (using a seperate page)
          all objects in the application, the cache with the Exception will be displayed
          as xxx.lock
          This can be avioded by catching all Exceptions
          Gareth


"Christian Corcino" <[email protected]> wrote in message
          news:3b5e3776$[email protected]..
          > I do not quite understand the purpose of the keys in the cache tag,
          > what are they used for.
          > These are the different keys :
          > parameter.key | page.key | request.key | application.key | session.key
          >
          > Can any one give me an example of when and how to use these keys,
          These are logical sub-keys you can use to distinguish two tags that would
          otherwise resolve to the same cached value. It helps prevent "overloading"
          the cache name with disjoint information needed to distinguish cache
          entries.
          For instance, our application supports multiple languages and uses a page
          variable called "language". Assume we want to cache the computed contents
          of a select element according to the user's language:
          <wl:cache name="selectValues_foobar" key="page.language" timeout="30m">
          [code to compute select values omitted]
          </wl:cache>
          This lets us use one name to describe the particular dataset while still
          allowing for independently cached values for differents values of
          "language".
          Felix Hack
          [email protected]

Weblogic cache tag usage experience? issues?

          I want to use weblogic custom tag "cache" in the jsp.
          I was wondering if anybody used it in high volume internet production environment.
          Experience/Issues with
          - memory usage
          - cache refresh issue while multiple threads accessing the jsp at the sam time
          - any lessons learned that you can share.
          Thanks.


          I want to use weblogic custom tag "cache" in the jsp.
          I was wondering if anybody used it in high volume internet production environment.
          Experience/Issues with
          - memory usage
          - cache refresh issue while multiple threads accessing the jsp at the sam time
          - any lessons learned that you can share.
          Thanks.

10G NEW FEATURE-HOW TO FLUSH THE BUFFER CACHE

제품 : ORACLE SERVER
작성날짜 : 2004-05-25
10G NEW FEATURE-HOW TO FLUSH THE BUFFER CACHE
===============================================
PURPOSE
이 자료는 Oracle 10g new feature 로 manual 하게
buffer cache 를 flush 할 수 있는 기능에 대하여 알아보도록 한다.
Explanation
Oracle 10g 에서 new feature 로 소개된 내용으로 SGA 내 buffer cache 의
모든 data 를 command 수행으로 clear 할 수 있다.
이 작업을 위해서는 "alter system" privileges 가 있어야 한다.
Buffer cache flush 를 위한 command 는 다음과 같다.
주의) 이 작업은 database performance 에 영향을 줄 수 있으므로 주의하여 사용하여야 한다.
SQL > alter system flush buffer_cache;
Example
x$bh 를 query 하여 buffer cache 내 존재하는 정보를 확인한다.
x$bh view 는 buffer cache headers 정보를 확인할 수 있는 view 이다.
우선 test 로 table 을 생성하고 insert 를 수행하고
x$bh 에서 barfil column(Relative file number of block) 과 file# 를 조회한다.
1) Test table 생성
SQL> Create table Test_buffer (a number)
2 tablespace USERS;
Table created.
2) Test table 에 insert
SQL> begin
2 for i in 1..1000
3 loop
4 insert into test_buffer values (i);
5 end loop;
6 commit;
7 end;
8 /
PL/SQL procedure successfully completed.
3) Object_id 확인
SQL> select OBJECT_id from dba_objects
2 where object_name='TEST_BUFFER';
OBJECT_ID
42817
4) x$bh 에서 buffer cache 내에 올라와 있는 DBARFIL(file number of block) 를 조회한다.
SQL> select ts#,file#,dbarfil,dbablk,class,state,mode_held,obj
2 from x$bh where obj= 42817;
TS# FILE# DBARFIL DBABLK CLASS STATE MODE_HELD J
9 23 23 1297 8 1 0 7
9 23 23 1298 9 1 0 7
9 23 23 1299 4 1 0 7
9 23 23 1300 1 1 0 7
9 23 23 1301 1 1 0 7
9 23 23 1302 1 1 0 7
9 23 23 1303 1 1 0 7
9 23 23 1304 1 1 0 7
8 rows selected.
5) 다음과 같이 buffer cache 를 flush 하고 위 query 를 재수행한다.
SQL > alter system flush buffer_cache ;
SQL> select ts#,file#,dbarfil,dbablk,class,state,mode_held,obj
2 from x$bh where obj= 42817;
6) x$bh 에서 state column 이 0 인지 확인한다.
0 은 free buffer 를 의미한다. flush 이후에 state 가 0 인지 확인함으로써
flushing 이 command 를 통해 manual 하게 수행되었음을 확인할 수 있다.
Reference Documents
<NOTE. 251326.1>

I am also having the same issue. Can this be addressed or does BEA provide 'almost'
working code for the bargin price of $80k/cpu?
"Prashanth " <[email protected]> wrote:
>
Hi ALL,
I am using wl:cache tag for caching purpose. My reqmnt is such that I
have to
flush the cache based on user activity.
I have tried all the combinations, but could not achieve the desired
result.
Can somebody guide me on how can we flush the cache??
TIA, Prashanth Bhat.

Info on JSP caching in WebLogic 5.1

          Hi,
          I found your name in the Weblogic newsgroup and hence decided to post this
          question to you. Hope you do'nt mind my asking it.
          I would like to know something about caching of Java Server Pages in WebLogic
          5.1. How effective is it for developing and deploying applications on WebLogic
          Server ? Has caching in WebLogic been tried out extensively in deploying applications
          before ? How successful have they been ?
          In particular, I would like to know if any deadlock occurrs in Java Server
          Page caching in WebLogic.
          Also can I force a cache to refresh within the timeout period (i.e., before
          the elapse of the timeout for the particular cache) ?
          Also, how is the async attribute used in <wl:cache> tag ? Is there any performance
          bottleneck occurring due to its usage ?
          I would love to have answers to all my questions. However even if I get some
          answers it will be highly appreciated.
          Regards,
          Sumantu


In WebLogic 6.0 register each jsp in the web.xml with a <servlet-name>, <jsp-file>
          and <load-on-startup>. For example:
          <web-app>
          <servlet>
          <servlet-name></servlet-name>
          <jsp-file></jsp-file>
          <load-on-startup></load-on-startup>
          </servlet>
          <servlet-mapping>
          <servlet-name></servlet-name>
          <url-pattern></url-pattern>
          </servlet-mapping>
          </web-app>
          The optional value of load-on-startup element must be a positive integer indicating
          the order in which the servlet should be loaded.
          In WebLogic 6.1 set the precompile parameter in weblogic.xml.
          <jsp-descriptor>
          <jsp-param>
          <param-name>
          precompile
          </param-name>
          <param-value>
          true
          </param-value>
          </jsp-param>
          </jsp-descriptor>
          Vaibhav wrote:
          > This solution is with web.xml, if I am
          > using weblogic.properties only and no web.xml, How do I specify precompile=true ?

Jsp Custom tags Weblogic 6.1

          Hi,
          I had posted a message before regarding the docs for weblogic custom tags, my
          query is whether the custom tags listed in the javadocs of weblogic api like BeanParamTag,
          FormAnchorTag etc should be used for development or not.
          Weblogic docs only talk about process, repeat and cache tags from development
          point of view.
          I'm studying the custom tags of weblogic 6.1.0 and i need to know whether the
          tags besides process,repeat and cache tags.
          Regards,
          Sujan


          Hi,
          I had posted a message before regarding the docs for weblogic custom tags, my
          query is whether the custom tags listed in the javadocs of weblogic api like BeanParamTag,
          FormAnchorTag etc should be used for development or not.
          Weblogic docs only talk about process, repeat and cache tags from development
          point of view.
          I'm studying the custom tags of weblogic 6.1.0 and i need to know whether the
          tags besides process,repeat and cache tags.
          Regards,
          Sujan

JSP Tags and pooling.

We are researching JSP Tags as a method of seperating our creative and coding efforts. Our research is showing that JSP tags is a resource hog and noticed that none of the JSP Tags are being pooled. Docs that we have looked at suggest that pooling does occur, but we do not see it happening. Is anyone using this technology and if so how is the performance?


Cameron,
          In general, what kind of "interesting bugs" and "design flaws" do you mean?
          I would expect that using any kind of cache can allow for bugs due to developers
          confusion... but are there inherent "bugs" (or design flaws) that are built into
          WL's Cache tag?
          Jack Lin
          Cameron Purdy wrote:
          > Install the latest SP. They are (relatively speaking) resource intensive.
          > However, properly implemented/used, this relative cost is close to 0.
          > (Instantiating a Java class and calling a few empty methods uses a couple
          > hundred clock cycles on a good JVM.) BTW Pooling is considerably more
          > expensive for simple objects than instantiating new ones. Also, due to
          > design flaws in the custom tag API, pooling JSP tags could lead to some
          > interesting bugs related to the lack of re-initialization.
          >
          > --
          >
          > Cameron Purdy
          > [email protected]
          > http://www.tangosol.com
          > WebLogic Consulting Available
          >
          > "Anthony Raiti" <[email protected]> wrote in message
          > news:39d4a35f$[email protected]..
          > We are researching JSP Tags as a method of seperating our creative and
          > coding efforts. Our research is showing that JSP tags is a resource hog and
          > noticed that none of the JSP Tags are being pooled. Docs that we have looked
          > at suggest that pooling does occur, but we do not see it happening. Is
          > anyone using this technology and if so how is the performance?

JRE Cache ignores the "Expire" and "Cache-Control: no-cache" directives.

My applet is using HttpURLConection to retrieve data from a server with Caching enabled. The cache contents are "revalidated" (via "if-modfied-since") each time the applet is started. However, subsequent requests to retrieve the same resource are always read from the cache with no validation even if the resource has expired.
The server is sending a valid "Expires:" tag and "Cache-Control: no-cache" tag in the response; but, the JRE refuses to recheck for an updated version of the resource even after the file has expired.
The JRE does seem to understand the "Cache-Control: no-store" tag; but, this is inefficient (no caching at all) when I'm tring to get it to not refetch the resource unless there's a change. Is there some other tag that the JRE is expecting to see?

I have a similar problem except that I want my pages to not cache at all. The server is setting the Cache-Control: max-age to 0 and the Expires to "now" but JRE seems to ignore these settings, but only sometimes. Sometimes pages are fetched from cache and sometimes from the server.
In my applet I'm using a normal URLConnection like this:
URLConnection uc = new URL("http://<server>/method").openConnection();
uc.connect();
InputStream is = uc.getInputStream();
is.read();When my request headers look like this:
accept-encoding: gzip
Host: <server>
Cache-Control: no-cache
Pragma: no-cache
User-Agent: Mozilla/4.0 (Windows XP 5.1) Java/1.6.0_13
Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2
Connection: keep-alivethe page will not be cached and is requested again but this time without the accept-encoding, Pragma and Cache-Control. The adding (and removal) of the headers seems to happen inside the JRE, though. I'm not explicitly setting them.
The response header of the first request looks like this:
HTTP/1.1 200 OK
Date: Wed, 20 May 2009 12:55:07 GMT
Server: Apache/2.2.11 (Win32) mod_jk/1.2.26 PHP/5.2.8
Cache-Control: max-age=0
Expires: Wed, 20 May 2009 12:55:07 GMT
Vary: User-Agent,Accept-Encoding
Content-Encoding: gzip
Keep-Alive: timeout=120, max=79
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: text/html;charset=iso-8859-1When the request is made with this header:
User-Agent: Mozilla/4.0 (Windows XP 5.1) Java/1.6.0_13
Host: <server>
Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2
Connection: keep-aliveThe response headers looks like this:
HTTP/1.1 200 OK
Date: Wed, 20 May 2009 12:55:07 GMT
Server: Apache/2.2.11 (Win32) mod_jk/1.2.26 PHP/5.2.8
Content-Length: 1016
Cache-Control: max-age=0
Expires: Wed, 20 May 2009 12:55:07 GMT
Vary: User-Agent,Accept-Encoding
Keep-Alive: timeout=120, max=83
Connection: Keep-Alive
Content-Type: text/html;charset=iso-8859-1And in this case the JRE sometimes fetches the request from the server and sometimes from cache. I have not been able to determine how the JRE decides to refresh, or why it sometimes sends an accept-encoding and Pragma header and sometimes not.
any help would be appreciated.
Alex

Caching gateway'd pages....

Edit: disregard this. Twitter's rate limiting means that if you try to gateway the json request you'll run out of your request limit very fast. I'll write an app to make the request.
I'm working on a twitter portlet. (by the way, if anyone has one already, stop me....) I was thinking of just grabbing one of the 8 million of the twitter widgets off the internet and just modify it to use the gateway. (Our portal is https, so normal widgets don't work without dislaying the mixed mode warning in IE).
The way most widgets work is they load the tweets via ajax. I gatewayed the http://twitter.com/user-stautuses/. page but I wasn't sure if i could cache the response on the portal.
My questions:
Does the portal cache gateway'd requests in a smilar manner as caching the initial portlet request? Does settign the minimum and maximum cache times have any affect on a gatewayed request?
In related news, when i was googling for alui caching i found this which doesn't seem to be in the normal alui blogrolls...
http://mauroy.blogspot.com/2009/05/caching-portlets-in-alui-6x.html
Edited by: Joel Collins on Jul 9, 2009 7:26 AM

Using the application scope is one way to do it.
I would recommend writing a CacheControl bean to handle this for you (or re-using an existing cache object)
You can put that bean into the application scope. Just to keep things neat and tidy.
How that bean then caches web pages is up to you
- Store them in memory (I would recommend a LinkedHashMap in LRU mode)
- Store them to disk - less memory intensive, a bit slower but can store more
How are you going to determine if a page is "the same"?
I think you should also consider the "no-cache" tags that a page may send with itself.
Caching can drive web application drivers nuts, as the page actually DOES change on every request.
Cheers,
evnafets

Caching Problem Persists!

Sevearl weeks ago I posted a topic about having a probelm
with our help windows being recalled when a user would hit the back
button in their browser. I tried a quick fix by inserting a no
cache tag in each of the help pages I created but it did not work.
Our developer believe it has to do with one of the javascripts
automatically created by Robohelp. Does nayone know of this probelm
elsewhere, or how to fix it???
Thanks!
Tim

Close, here is my sequence:
1. I open the primary application, which runs in a Web
browser.
2. I click help, and a new browser window opens to show
WebHelp.
3. I read help topics, follow links, use the back button,
maybe use the TOC and index -- all the while, the primary
application window is still open in the background.
4. I close the HELP window and decide I need to go back in
the primary application
5. I click the back button in the browser and the HELP window
reopens!
We found a work around, where when you intiially click on the
HELP link it opens the help window, but it also opens a window that
runs in the background. When you close the help window, the
background window remains open, but now the user can navigat
backwards using the back button in the browser without any
problems. However there have been some bugs and issues with this
(the app opens the correct help window, but becomes confused and
redirects to another page..)
Here is a link to the forum where the fix was located:
http://www.adobe.com/cfusion/webforums/forum/messageview.cfm?forumid=65&catid=451&threadid =1140134&enterthread=y
I am looking for something that uses the .js file inlcuded,
but with some type of modification to kill this issue.
Thanks,
Tim

Caching binary content (raw files) in Weblogic -- in-built support ?

There are some raw binary files on disk (PDFs , images etc).
There is a servlet which receives requests for files, does some authorization
checks -- then reads file & delivers binary content to HTTP response.
To avoid file read for each request, we need to cache the binary content in Weblogic.
The important design aspects for this caching wud be : (i) some files can be quite
large (ii) frequency of request can vary greatly between different files (ii)
the files are not modified on disk frequently -- hence the cache can be refreshed
after longer intervals
Does Weblogic provide any built-in caching mechanism for such operations ?
Thanks,
Subodh

To avoid file read for each request, we need to cache the binary contentin Weblogic.
Does Weblogic provide any built-in caching mechanism for such operations ?There are some JSP cache tags.
http://edocs.bea.com/wls/docs70/jsp/customtags.html#56944
There are various caching packages, both commercial and open source. For
what you're describing, I think you'd have no problem using OSCache, which
is open source.
http://www.opensymphony.com/oscache/
If you need clustered cacheing use Coherence.
http://www.tangosol.com/coherence.jsp
Peace,
Cameron Purdy
Tangosol, Inc.
http://www.tangosol.com/coherence.jsp
Tangosol Coherence: Clustered Replicated Cache for Weblogic
"Subodh" <[email protected]> wrote in message
news:3fd4236c$[email protected]..
>

Caching JSP output

All,
          Any help or pointers to solutions would be greatly appreciated.
          We have some JSPs that produce relatively static output. Is there a way in
          WL to cache the output, instead on recreating it every time? I know that
          the Caucho JSP engine will do this (it uses browser caching directives).
          Would we need to create our own caching mechanism?
          Thanks,
          Wade Matveyenko


Good idea, I'll file it as a per.
          Sam
          "Dimitri Rakitine" <[email protected]> wrote in message
          news:[email protected]...
          > Oh. Then why not use maxSize cache backed by the SoftReferences?
          > For example, in the BubblingCache store hard references:
          >
          > class KeyValuePair {
          > public Object key;
          > public Object value; // hard reference to prevent cached object
          > // from being gc'ed.
          > }
          >
          > in the sorted array and SoftReferences in the HashMap - that way it will
          > behave like a normal maxSize cache and, if we are lucky, will be able to
          > return cached objects even after their hard references are removedi
          (maxSize
          > reached). If the garbage collector is too eager to clear SoftReferences
          there
          > will be no performance penalty.
          >
          > Sam Pullara <[email protected]> wrote:
          > > Essentially, soft references in HotSpot are not useful as caches. Here
          is
          > > the bug/per from the
          > > Java Developer Connection:
          >
          > > http://developer.java.sun.com/developer/bugParade/bugs/4239645.html
          >
          > > What you find is that your newly made soft reference rarely makes it to
          the
          > > long term generation
          > > in the collector and thus gets cleared almost immediately. There is
          some
          > > stochastic effect that
          > > smoothes it somewhat over time but it is nothing like the perfect
          behaviour
          > > you get from the classic
          > > virtual machine.
          >
          > > Although the tag detects what VM it is in and determines a good default,
          > > there is the ability to
          > > force softreferences either on or off. You can set either
          >
          > > weblogicx.jsp.tags.CacheTag.softreferences=true
          > > or
          > > weblogicx.jsp.tags.CacheTag.nosoftreferences=true
          >
          > > To force it one way or the other. These are System properties, not
          WebLogic
          > > properties, so you
          > > will either need to set them on the command line with -D or you can use
          the
          > > special weblogic.properties
          > > syntax and prepend java.system.property to the property names to set
          them,
          > > like:
          >
          > > java.system.property.weblogicx.jsp.tags.CacheTag.softreferences=true
          >
          > > Some of the documentation is a tad out of date. There will be a more
          formal
          > > release of the tag library
          > > in the next release of the WebLogic Server.
          >
          > > Sam
          >
          > > "Dimitri Rakitine" <[email protected]> wrote in message
          > > news:[email protected]...
          > >> It says: 'Unfortunately, due to incompatibilities with the HotSpot's VM
          > > and the Classic VM, we must
          > >> not use soft references when we are running within HotSpot. '
          > >>
          > >> Could you please elaborate what these incompatibilities are?
          > >>
          > >> Thanks.
          > >>
          > >> Sam Pullara <[email protected]> wrote:
          > >> > Service Pack 5 includes a cache tag. Attached is a war file with the
          > >> > javadocs.
          > >> > You should find it in lib/weblogic-tags-510.jar or use the one in the
          > > war
          > >> > file.
          > >>
          > >> > Sam
          > >>
          > >> > "Dimitri Rakitine" <[email protected]> wrote in message
          > >> > news:[email protected]...
          > >> >> You can use squid (http://www.squid-cache.org) in front of your
          > >> >> Weblogic server(s) - it will do caching for you.
          > >> >>
          > >> >> Wade Matveyenko <[email protected]> wrote:
          > >> >> > All,
          > >> >> > Any help or pointers to solutions would be greatly appreciated.
          > >> >>
          > >> >> > We have some JSPs that produce relatively static output. Is there
          a
          > > way
          > >> > in
          > >> >> > WL to cache the output, instead on recreating it every time? I
          know
          > >> > that
          > >> >> > the Caucho JSP engine will do this (it uses browser caching
          > > directives).
          > >> >> > Would we need to create our own caching mechanism?
          > >> >>
          > >> >> > Thanks,
          > >> >> > Wade Matveyenko
          > >> >>
          > >> >> --
          > >> >> Dimitri
          > >> >> http://dima.dhs.org
          > >>
          > >> --
          > >> Dimitri
          > >> http://dima.dhs.org
          >
          > --
          > Dimitri
          > http://dima.dhs.org

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