FYI tfennelly tracking performance for SSE here.

I honestly think this is down to something else starving requests like this from getting a service thread. That said ... I'm going to refactor the config path so as to remove the lock on the session object, which would only block on multiple requests from the same client i.e. would not block across clients.

tfennelly sounds like a good first step to deduce whats going on there. If we can rule out locking at least we can investigate down another route.

PR: https://github.com/jenkinsci/blueocean-plugin/pull/512

Code changed in jenkins
User: Tom Fennelly
Path:
src/main/java/org/jenkinsci/plugins/ssegateway/Endpoint.java
src/main/java/org/jenkinsci/plugins/ssegateway/EventHistoryStore.java
src/main/java/org/jenkinsci/plugins/ssegateway/SubscriptionConfigQueue.java
src/main/java/org/jenkinsci/plugins/ssegateway/sse/EventDispatcher.java
src/test/java/org/jenkinsci/plugins/ssegateway/EndpointUnitTest.java
http://jenkins-ci.org/commit/sse-gateway-plugin/4c2e42882f6ff87f9250022b7c0c8949d1b1fb60
Log:
JENKINS-38252 Async subs configuration (#11)

• Removing synchronization around subscription configuration

Make it async

• Removed unneeded synchronization around channel subs counters

• Capture authentication when the dispatcher is created

Doing it async results in it being done outside the context of a user request, resulting in every subscription being created for ANONYMOUS and therefore many events not being delivered because of permissions restrictions.