Module initialization is not thread-safe ---------------------------------------- Key: ISPN-9541 URL: https://issues.redhat.com/browse/ISPN-9541 Project: Infinispan Issue Type: Bug Components: Core, Server Affects Versions: 9.4.0.CR3 Reporter: Dan Berindei Assignee: Dan Berindei Priority: Major Fix For: 10.0.0.CR3 In my ISPN-9127 fix I created a {{BasicComponentRegistry}} interface that represents a mostly-read-only collection of components. It has {{replaceComponent()}} method and a {{rewire()}} method for testing purposes, but it turns out modules were also relying on the ability to replace existing components in order to work. Replacing global components is normally safe during the {{ModuleLifecycle.cacheManagerStarting()}}, because none of the components are started yet, so when a component starts later we can still start its dependencies first. But because some modules starts some global components, e.g. by calling {{manager.getCache(name)}}, that assumption breaks. The {{infinispan-server-event-logger}} module is a bit more sneaky: it doesn't replace a component, instead it replaces the actual implementation of the event logger in the {{EventLogManager}} component. Events that happen before the module's {{cacheManagerStarting()}} or after {{cacheManagerStopping()}} will be silently dropped from the persistent event log. I am investigating making the module a factory of factories. Instead of having a monolitic {{cacheManagerStarting()}} method, it could define a set of components that it can create, and a set of components that should be started before the cache manager is "running". We probably need a way to depend on other modules as well, maybe reusing the {{@Inject}} and {{@ComponentName}} annotations.