Saturday, September 20, 2014

JDeveloper 12c ADF View Token Performance Improvement

There is known limitation in ADF 11g, related to accessing application in the same session from multiple browser tabs. While working with multiple browser tabs, eventually user is going to consume all view tokens, he will get timeout error once he returns back to the previous browser tab. Unused browser tab is producing timeout, because ADF 11g is sharing the same cache of view tokens for all browser tabs in the same session. This means the recent mostly used browser tab is going to consume all view tokens, other browser tab would loose the last token and screen state will be reset. This behaviour is greatly improved in ADF 12c with separate view token cache supported per each browser tab. If your application is designed to allow user access through multiple browser tabs in the same session, you should upgrade to ADF 12c for better performance.

I'm going to post results of a test with 11g and 12c. Firstly I'm going to present ADF 11g case and then ADF 12c.

ADF 11g view token usage:

Sample application contains one regular button, with PartialSubmit=false, to generate new view token on every submit:


Max Tokens parameter in web.xml is set to 2, to simulate token usage:



To see the debug output for view tokens usage on runtime, you should set special parameter - org.apache.myfaces.trinidadinternal.DEBUG_TOKEN_CACHE=true



On runtime try to open two browser tabs. You are going to see two view tokens consumed and reported in the log:



Press Test View Token button in the second tab, this would consume another view token. Remember, we have set maximum two tokens, no in the log it says - removing/adding token. This means, we have consumes both available tokens (for both tabs) and token from the first tab is replaced:



Go back to the first browser tab, try to press the same Test View Token button and you are going to get time out error - view token is lost and you need to reload the tab:


ADF 12c view token usage:

Sample application in the same way as in 11g, also implemented simple button set with PartialSubmit=false. This would force to use new view token on each submit:


Max Tokens parameter in web.xml, again is set to 2:


Two browser tabs are opened and two view tokens are consumed:


Press Test View Token in second browser tab, you are not going to see in the log information about removing/adding token (differently to 11g). This means, view token from the first browser tab still remains in the cache, second browser tab maintains its own view token cache:


Go back to the first browser tab, press Test View Token button - application works fine, no time out error as it was in 11g:


Download sample application ADF 11g and 12c examples - ViewTokensTest.zip.

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