Wouldn't it be a valid scenario to change the cache expiry time as in my
case? As you've said, I understand that we cannot expect every new version
of the app to have cache configuration changes. But during testing or
initial development i think it could happen. Even in that case this is not
a blocking issue i think. I just want to understand how we should work with
that. :)

On Wed, Oct 29, 2014 at 6:48 PM, Afkham Azeez <[email protected]> wrote:

> It doesn't happen like that in practice. The developer suddenly doesn't
> change the mind and change the cache configuration on the fly. These
> parameters are fixed, and will be set upon cache creation.
>
> On Wed, Oct 29, 2014 at 6:15 AM, Gayashan Amarasinghe <[email protected]>
> wrote:
>
>> Thanks Azeez. Understood. However in case the developer wanted to change
>> the cache configuration of an existing cache what is the recommended
>> approach? Only possible way would be to make the cache have a different
>> name?
>>
>> On Wed, Oct 29, 2014 at 6:37 PM, Afkham Azeez <[email protected]> wrote:
>>
>>> You cannot call the builder twice when the cache already exists. Other
>>> teams such as IS use both the getCache & the builder method with proper
>>> synchronization which will return the cache if it exists, or will build &
>>> return the cache with custom parameter if it does not exist. I will try to
>>> write a sample code segment and publish on my blog today. That can be made
>>> into a class called CachingUtil or something.
>>>
>>> Azeez
>>>
>>> On Wed, Oct 29, 2014 at 5:59 AM, Gayashan Amarasinghe <[email protected]
>>> > wrote:
>>>
>>>> Hi Azeez,
>>>>
>>>> During Carbon testing i've created a simple web app that utilize the
>>>> cache (source code at [1]). In this web app I've created a cache with
>>>> custom expiry and deployed it in a cluster and hit it using jmeter. During
>>>> testing i changed the expiry time of the cache prorgrammatically and tried
>>>> to redeploy the web app. But since the server was not restarted the cache
>>>> created by the previous web app was already there. (I didn't change the
>>>> name of the cache manager or the cache) As a result the following exception
>>>> was thrown.
>>>>
>>>> TID: [-1234] [] [2014-10-29 12:27:57,185] ERROR
>>>> {org.apache.catalina.core.StandardWrapperValve} -  Allocate exception for
>>>> servlet org.wso2.carbon.CarbonTest.CachingTest
>>>> {org.apache.catalina.core.StandardWrapperValve}
>>>> javax.cache.CacheException: Cache expiringCache already exists
>>>>     at
>>>> org.wso2.carbon.caching.impl.CarbonCacheManager.createCacheBuilder(CarbonCacheManager.java:96)
>>>>     at org.wso2.carbon.CarbonTest.CachingTest.init(CachingTest.java:38)
>>>>     at javax.servlet.GenericServlet.init(GenericServlet.java:158)
>>>>     at
>>>> org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1279)
>>>>     at
>>>> org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1192)
>>>>     at
>>>> org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:864)
>>>>     at
>>>> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:134)
>>>>     at
>>>> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
>>>>     at
>>>> org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
>>>>     at
>>>> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
>>>>     at
>>>> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
>>>>     at
>>>> org.wso2.carbon.statistics.webapp.RequestIntercepterValve.invoke(RequestIntercepterValve.java:43)
>>>>     at
>>>> org.wso2.carbon.bam.webapp.stat.publisher.WebAppStatisticPublisherValve.invoke(WebAppStatisticPublisherValve.java:104)
>>>>     at
>>>> org.wso2.carbon.tomcat.ext.valves.CompositeValve.continueInvocation(CompositeValve.java:178)
>>>>     at
>>>> org.wso2.carbon.tomcat.ext.valves.CarbonTomcatValve$1.invoke(CarbonTomcatValve.java:47)
>>>>     at
>>>> org.wso2.carbon.webapp.mgt.GhostWebappDeployerValve.invoke(GhostWebappDeployerValve.java:141)
>>>>     at
>>>> org.wso2.carbon.webapp.mgt.TenantLazyLoaderValve.invoke(TenantLazyLoaderValve.java:56)
>>>>     at
>>>> org.wso2.carbon.tomcat.ext.valves.TomcatValveContainer.invokeValves(TomcatValveContainer.java:47)
>>>>     at
>>>> org.wso2.carbon.tomcat.ext.valves.CompositeValve.invoke(CompositeValve.java:141)
>>>>     at
>>>> org.wso2.carbon.tomcat.ext.valves.CarbonStuckThreadDetectionValve.invoke(CarbonStuckThreadDetectionValve.java:154)
>>>>     at
>>>> org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
>>>>     at
>>>> org.wso2.carbon.tomcat.ext.valves.CarbonContextCreatorValve.invoke(CarbonContextCreatorValve.java:52)
>>>>     at
>>>> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
>>>>     at
>>>> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
>>>>     at
>>>> org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
>>>>     at
>>>> org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
>>>>     at
>>>> org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1721)
>>>>     at
>>>> org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1679)
>>>>     at
>>>> java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
>>>>     at
>>>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
>>>>     at java.lang.Thread.run(Thread.java:662)
>>>>
>>>>
>>>> This is going to be an issue when developers try to redeploy a webapp
>>>> with modifications to the cache configurations. Is this a bug or the
>>>> intended behavior? AFAIU we should not let this happen. WDYT?
>>>>
>>>> [1]
>>>> https://github.com/GayashanNA/CarbonCachingTestWebapp/blob/master/src/main/java/org/wso2/carbon/CarbonTest/CachingTest.java
>>>>
>>>> ​Thanks.
>>>> /Gayashan​
>>>>
>>>> --
>>>> *Gayashan Amarasinghe*
>>>> Software Engineer | Platform TG
>>>> WSO2, Inc. | http://wso2.com
>>>> lean. enterprise. middleware
>>>>
>>>> Mobile : +94718314517
>>>> Blog : gayashan-a.blogspot.com
>>>>
>>>
>>>
>>>
>>> --
>>> *Afkham Azeez*
>>> Director of Architecture; WSO2, Inc.; http://wso2.com
>>> Member; Apache Software Foundation; http://www.apache.org/
>>> * <http://www.apache.org/>*
>>> *email: **[email protected]* <[email protected]>
>>> * cell: +94 77 3320919 <%2B94%2077%203320919>blog: *
>>> *http://blog.afkham.org* <http://blog.afkham.org>
>>> *twitter: **http://twitter.com/afkham_azeez*
>>> <http://twitter.com/afkham_azeez>
>>> *linked-in: **http://lk.linkedin.com/in/afkhamazeez
>>> <http://lk.linkedin.com/in/afkhamazeez>*
>>>
>>> *Lean . Enterprise . Middleware*
>>>
>>
>>
>>
>> --
>> *Gayashan Amarasinghe*
>> Software Engineer | Platform TG
>> WSO2, Inc. | http://wso2.com
>> lean. enterprise. middleware
>>
>> Mobile : +94718314517
>> Blog : gayashan-a.blogspot.com
>>
>
>
>
> --
> *Afkham Azeez*
> Director of Architecture; WSO2, Inc.; http://wso2.com
> Member; Apache Software Foundation; http://www.apache.org/
> * <http://www.apache.org/>*
> *email: **[email protected]* <[email protected]>
> * cell: +94 77 3320919 <%2B94%2077%203320919>blog: *
> *http://blog.afkham.org* <http://blog.afkham.org>
> *twitter: **http://twitter.com/afkham_azeez*
> <http://twitter.com/afkham_azeez>
> *linked-in: **http://lk.linkedin.com/in/afkhamazeez
> <http://lk.linkedin.com/in/afkhamazeez>*
>
> *Lean . Enterprise . Middleware*
>



-- 
*Gayashan Amarasinghe*
Software Engineer | Platform TG
WSO2, Inc. | http://wso2.com
lean. enterprise. middleware

Mobile : +94718314517
Blog : gayashan-a.blogspot.com
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