There are at least a couple more mutable messages: StartRoutineDiscoveryMessage and SchemaProposeDiscoveryMessage.
I agree that here that making all messages immutable are highly desired (e.g. it will allow implementation of new discovery protocols). But so far I do not understand why marker interface is a better approach. Pavel, could you please elaborate? чт, 24 окт. 2019 г. в 17:55, Pavel Kovalenko <jokse...@gmail.com>: > > Hi Nikita, > > 1. As I can understand, this functionality is needed if a custom message is > needed to be processed only on the coordinator node. I'm not following for > what purposes it was implemented and I see the real usage only in tests. > As far as this functionality is not used in production code, I suggest to > remove it. > 2. This method needs if we want to perform a message mutation during > sending it over the ring. Each node after message receive can mutate its > state and resend to another node. I know only 2 mechanisms where this > functionality is needed: > binary metadata propagation and cluster-wide metrics collecting. From my > side of view, this is poor approach and we should avoid discovery messages > mutation and use only immutable messages. It can be removed from the custom > message interface and marker interface should be introduced instead. > > чт, 24 окт. 2019 г. в 16:35, Nikita Amelchev <nsamelc...@gmail.com>: > > > Hi, Igniters. > > > > The discovery custom message interface has two methods the use of > > which is not clear to developers: > > > > 1. The stopProcess() method. Currently, it works only if the zookeeper > > discovery configured. It doesn't work in TcpDiscoverySpi. I did not > > find any usages of this method except tests. I suggest to remove it > > from the discovery custom message interface. > > > > 2. The isMutable() method. It works in TcpDiscoverySpi but not in the > > zookeeper SPI. Using this method is opaque to the developer when he > > wants to add new features to the project. In general, it cannot be > > used because may not be supported depending on the configuration. > > Perhaps some functionality that uses it is not working correctly with > > zookeeper configured. It seems we should avoid it in the custom > > message interface too. > > > > WDYT? > > > > -- > > Best wishes, > > Amelchev Nikita > > -- Best regards, Ivan Pavlukhin
