20.4.6. SingleRetryInterceptor

The RetryInterceptor is useful in many use cases, but a disadvantage it has is that it will continue attempting to re-lookup the HA proxy in JNDI until it succeeds. If for some reason it cannot succeed, this process could go on forever, and thus the EJB call that triggered the RetryInterceptor will never return. For many client applications, this possibility is unacceptable. As a result, JBoss doesn't make the RetryInterceptor part of its default client interceptor stacks for clustered EJBs.

In a previous release, a new flavor of retry interceptor was introduced, the org.jboss.proxy.ejb.SingleRetryInterceptor. This version works like the RetryInterceptor, but only makes a single attempt to re-lookup the HA proxy in JNDI. If this attempt fails, the EJB call will fail just as if no retry interceptor was used. The SingleRetryInterceptor is now part of the default client interceptor stacks for clustered EJBs.

The downside of the SingleRetryInterceptor is that if the retry attempt is made during a portion of a cluster restart where no servers are available, the retry will fail and no further attempts will be made.