Async service with EJB pool blocks threads not used --------------------------------------------------- Key: WFLY-4330 URL: https://issues.jboss.org/browse/WFLY-4330 Project: WildFly Issue Type: Bug Components: EJB Affects Versions: 8.2.0.Final Reporter: Janario Oliveira Assignee: Bartosz Baranowski Attachments: wildfly-thread-pool.zip I've created a bean pool to limit the number of some instances. In that case maximum 5 instances. <pools> <bean-instance-pools> <strict-max-pool name="slsb-max5" max-pool-size="5" instance-acquisition-timeout="5" instance-acquisition-timeout-unit="MINUTES"/> ... </bean-instance-pools> </pools> The idea was to have some async service that work simultaneous. @Stateless @Pool("slsb-max5") public class AsyncService { @Asynchronous public Future<LocalDateTime> async2Seconds() { //some parallel work... } } The problem is when I invoke simultaneous more than 5 times it blocks the threads even it is not using (async thread-pool-name="default", default=10) Attached an example project (configure slsb-max5 pool and access /test-thread-pool/rest/async-resource)