OF-3164: Avoid user lookup for JIDs without node to reduce exception overhead #3122
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…overhead Prevent execution of user lookup logic when the provided JID has no node. JIDs without a node part cannot represent a local user, yet currently flow through UserManager.isRegisteredUser(), which relies on exception-based control flow when the user does not exist. Thread dumps show significant CPU time spent constructing UserNotFoundException instances (Throwable.fillInStackTrace) on this hot path. This change short-circuits the lookup for node-less JIDs, avoiding the exception-heavy path and reducing unnecessary CPU usage under load. Note: This is a partial workaround. A full fix should refactor user existence checks to avoid exceptions for normal control flow.
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Prevent execution of user lookup logic when the provided JID has no node. JIDs without a node part cannot represent a local user, yet currently flow through UserManager.isRegisteredUser(), which relies on exception-based control flow when the user does not exist.
Thread dumps show significant CPU time spent constructing UserNotFoundException instances (Throwable.fillInStackTrace) on this hot path.
This change short-circuits the lookup for node-less JIDs, avoiding the exception-heavy path and reducing unnecessary CPU usage under load.
Note: This is a partial workaround. A full fix should refactor user existence checks to avoid exceptions for normal control flow.