We want to use our own scheduler for Timers but even if the infrastracture is in place one can not configure it's own implementation of TimerSession.
The <timer-session/> element allows only target ='ejb' and nothing else will be parsed by the method TimerSessionBinding.parse(). I can't understand why can't I provide my own implementation of TimerSession.

the Solution would be to change add and attribute className to <timer-session/> element and to change the TimerSessionBinding.parse() method like this :

objectDescriptor.setClassName(XmlUtil.attribute(element, "class"));

you can also add a target like 'custom' and only then check the 'class' attribute. Something like this:

public Object parse(Element element, Parse parse, Parser parser) {
ObjectDescriptor objectDescriptor = new ObjectDescriptor();

String target = XmlUtil.attribute(element, "target");

if ((target!=null){
if ("ejb".equalsIgnoreCase(target)))

{ objectDescriptor.setClassName("org.jbpm.enterprise.internal.ejb.EnterpriseTimerSession"); }

else if ("custom".equalsIgnoreCase(target)))

{ objectDescriptor.setClassName(XmlUtil.attribute(element, "class")); }

} else

{ // wire the JobExecutorTimerSession objectDescriptor.setClassName(JobExecutorTimerSession.class.getName()); // inject fields objectDescriptor.addInjection("transaction", new TransactionRefDescriptor()); objectDescriptor.addInjection("jobExecutor", new EnvDescriptor(JobExecutor.class)); objectDescriptor.addInjection("session", new ContextTypeRefDescriptor(Session.class)); }

return objectDescriptor;
}