Investigated the usage of EmbeddedLeaderService, as you said, it is mainly used in MiniCluster.
The difference between EmbeddedLeaderService and ZooKeeperLeader(Election|Retrieval)Service is that the latter uses component host and port pre-configured while the former configured at the runtime. I'm not sure when proceeding FLINK-10333 whether implement such a in memory leader election service or let MiniCluster use the standalone one is preferred. Best, tison. Zili Chen <wander4...@gmail.com> 于2019年8月5日周一 下午4:39写道： > Hi Till, > > SingleLeaderElectionService is an effectively subclass of > EmbeddedLeaderService. The merge work can be done as the > minor patch attached. > > I came into this area when working on FLINK-10333, implementing > LeaderElectionService as the document describes. I noticed that > besides Standalone and ZooKeeper implementation there is an > in memory LeaderElectionService, EmbeddedLeaderService. > > Before thinking whether it could be replace with the Standalone > one, I found SingleLeaderElectionService which is an effectively > subclass of it. Thus I started this issue to hear from the > community. > > Best, > tison. > > > Till Rohrmann <trohrm...@apache.org> 于2019年8月2日周五 下午5:59写道： > >> I think at the moment SingleLeaderElectionService is not really used since >> it is part of the YarnIntraNonHaMasterServices. The idea of these ha >> services was to offer a different ha implementation which slightly >> different guarantees. Concretely, the YarnIntraNonHaMasterServices handle >> operator and TaskManager faults but not master faults. >> >> The EmbeddedHaServices are only used by the MiniCluster. >> >> I'm not so sure whether the refactoring is so easy because >> EmbeddedLeaderElectionService is an inner class of EmbeddedLeaderService >> and calls methods of this class. Why do you wanna change anything there? >> >> Cheers, >> Till >> >> On Fri, Aug 2, 2019 at 6:33 AM Zili Chen <wander4...@gmail.com> wrote: >> >> > Hi devs, >> > >> > I found that these two classes are quite similar except >> > SingleLeaderElectionService has a pre-config leader id. >> > >> > However, I don't see use points of that leader id. Also >> > a random UUID would work as a DEFAULT_LEADER_ID(0). >> > I consider whether we could replace SingleLeaderElectionService >> > with EmbeddedLeaderElectionService, or merge. >> > >> > Best, >> > tison. >> > >> >
