CODEWITHSUNDEEP
javajakarta-eetimerejbwebsphere-liberty
schuno
schuno

Reputation: 585

Creating an EJB Timer in Liberty

I need to create a EJB timer (using @Schedule), but have read that this is not supported in a Websphere Liberty profile? According to a previously posted question on StackOverflow, it wasn't supported as of 08/2013:

Java EE-Timer / @Schedule in Websphere Liberty Profile

Currently when I try to use the @Schedule annotation I get the following exception:

[ERROR   ] CWWKZ0004E: An exception occurred while starting the application 
<EAR>. The exception message was: com.ibm.ws.container.service.state.StateChangeException: com.ibm.ws.exception.RuntimeError: java.lang.IllegalStateException: The ejbPersistentTimer feature is enabled, but the defaultEJBPersistentTimerExecutor persistent executor cannot be resolved. The most likely cause is that the DefaultDataSource datasource has not been configured. Persistent EJB timers require a datasource configuration for persistence.

The problem is I DO have a default data source defined. Here is the EJB code - it is very simple because I was just trying to test out timer functionality:

import javax.ejb.Schedule;
import javax.ejb.Stateless;

@Stateless
public class TimerBean {

    @Schedule(second="*/10", persistent=false)
    public void doSomething() {
        System.out.println("Hello World!");
    }

}

Update:

I changed my dataSource id to "DefaultDataSource", and now I am getting a different exceptions in my console when starting the server:

[ERROR   ] WTRN0078E: An attempt by the transaction manager to call start on a transactional resource has resulted in an error. The error code was XAER_RMERR. The exception stack trace follows: javax.transaction.xa.XAException: com.microsoft.sqlserver.jdbc.SQLServerException: Could not find stored procedure 'master..xp_sqljdbc_xa_start'.
at com.microsoft.sqlserver.jdbc.SQLServerXAResource.DTC_XA_Interface(SQLServerXAResource.java:647)
at com.microsoft.sqlserver.jdbc.SQLServerXAResource.start(SQLServerXAResource.java:679)
at com.ibm.ws.rsadapter.spi.WSRdbXaResourceImpl.start(WSRdbXaResourceImpl.java:1189)
at [internal classes]

[ERROR   ] J2CA0030E: Method enlist caught javax.transaction.SystemException: XAResource start association error:XAER_RMERR
at com.ibm.tx.jta.impl.RegisteredResources.startRes(RegisteredResources.java:1048)
at [internal classes]
Caused by: javax.transaction.xa.XAException: com.microsoft.sqlserver.jdbc.SQLServerException: Could not find stored procedure 'master..xp_sqljdbc_xa_start'.
at com.microsoft.sqlserver.jdbc.SQLServerXAResource.DTC_XA_Interface(SQLServerXAResource.java:647)
at com.microsoft.sqlserver.jdbc.SQLServerXAResource.start(SQLServerXAResource.java:679)

Is this the result of the timer attempting to write to my SQL DB, and if so, is there a way to avoid this?

Upvotes: 4

Views: 6037

Answers (4)

Archimedes Trajano
Archimedes Trajano

Reputation: 41240

  1. Add a new Database Store and provide it a reference to a Data Source. If you don't have one for the EJB timer tables or want a distinct one you can create a Data Source underneath the Database Store. Ensure you provide it an ID
  2. Add EJB Container -> EJB Timer Service -> EJB Persistent Timers Scheduled Executor
  3. On the EJB Persistent Timers Scheduled Executor set the Persistent task store reference to the ID of the Database Store

That should get rid of the error and will not require you to switch to EJB Lite.

Upvotes: 0

Andy Guibert
Andy Guibert

Reputation: 42926

It looks like you have the ejbPersistentTimer-3.2 feature turned on, since you are getting exceptions for having a DataSource configured.

If you are going to use ejbPersistentTimer-3.2 (or ejb-3.2 which includes it) you need to configure a datasource to be used for persistent timers.

Since you don't need persistent EJB timers (because you have persistent=false in your @Schedule annotation) you can remove the ejbPersistentTimer-3.2 feature and just use the ejbLite-3.2 feature (which doesn't include the persistent timer feature).

The ejbLite-3.2 feature includes support for non-persistent timers, and you won't need to worry about configuring a DataSource.

Upvotes: 5

Alasdair
Alasdair

Reputation: 3176

EJB timers are supported with WAS Liberty provided you use 8.5.5.6 or newer which is fully compliant with Java EE 7.

Upvotes: 1

Mike
Mike

Reputation: 151

From the IBM article at http://www.ibm.com/developerworks/websphere/library/techarticles/1404_vines1/1404_vines1.html, it looks like it is not available and you'll have to go third party:

The EJB Timer Service is not supported on Liberty profile or Liberty Core. If your application uses the EJB Timer Service, you can select one of these options: Deploy this part of your application in the WebSphere Application Server Full profile. Use other third-party scheduling libraries. Note: Although the second option is listed as a complex approach, its complexity can be simplified if a small number of timers are involved.

Update:

A little further research found this thread which seems to offer a solution (at least there's an accepted answer):

https://developer.ibm.com/answers/questions/187132/ejbpersistenttimer-32/

Upvotes: -1

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