The number of JGroup threads is 200
by default.
While it can be configured using the property Java system property jgroups.thread_pool.max_threads
, we advise keeping it at this value.
As shown in experiments, the total number of Quarkus worker threads in the cluster must not exceed the number of threads in the JGroup thread pool of 200 in each node to avoid deadlocks in the JGroups communication.
Given a Keycloak cluster with four Pods, each Pod should then have 50 Quarkus worker threads.
Use the Keycloak configuration option http-pool-max-threads
to configure the maximum number of Quarkus worker threads.