Change default flow control protocol back to UFC/MFC ---------------------------------------------------- Key: ISPN-11377 URL: https://issues.redhat.com/browse/ISPN-11377 Project: Infinispan Issue Type: Task Components: Configuration, Core Affects Versions: 9.4.18.Final, 10.1.2.Final, 11.0.0.Alpha1 Reporter: Dan Berindei Assignee: Dan Berindei Priority: Major Fix For: 10.1.4.Final, 11.0.0.Alpha2, 9.4.19.Final The server default configuration started using {{UFC_NB}} and {{MFC_NB}} in order to avoid blocking on the Netty event loop threads, slowing client requests, and then the core default configurations started using {{UFC_NB}} and {{MFC_NB}} as well with ISPN-9886. Unfortunately the _NB variants aren't really non-blocking: they have an extra queue for messages that require more credits, but that queue is limited (2MB by default), and once the queue is full, they also block. They also have much more complex locking than the blocking variants: we actually had to increase max_credits from 2MB to 3MB in order to get the same performance with {{UFC_NB}} that we had with {{UFC}}. We're changing the defaults back to {{UFC}} and {{MFC}} while we investigate possible alternatives to avoid blocking.