Hi, I have worked on "cluster-" branch for several days, but still not finished. As I have no much time to finish it, I'd like to ask cooperators working on it together. Please let me know if you want to join.
"cluster-" branch is not for fixing any bug in the cluster module, but just for refactoring the codes to make the structure similar to the server module. Some ideas in the branch: 1. split Thrift RPC service and RPC implementation. In the server module, we have extracted a class called ThriftService, which is responsible for starting a RPC service. We just need to ingest a RPC implementation to it. However, in the cluster module, some RPC classes mixed them, which causes code duplication, code inconsistencies, and hard to understand. 2. weaken the role of MetaGroupMember. metaGroupMember is just an engine for serving meta raft group, which should not control the whole server too deep. So, many fields (like coordinator, etc.) are extracted to ClusterIoTDB (renamed from ClusterMain), and ClusterIoTDB is responsible for creating them. MetaGroupMember only can modify these fields, rather than creating them. That is, the lifecycle of these fields belongs to ClusterIoTDB, rather than MetaGroupMember. BTW, MetaGroupMember will be renamed to MetaGroupEngine. 3. Similar with the relationship between StorageEngine and StorageProcessor in the server module, DataGroupMember can be considered as StorageProcessor, and we need a DataGroupEngine to control them. 4. I am considering how to refactor the ClientPool. there are too many in the codes. But I have no clear idea now. The 2nd and 3rd refactors will lead to many unexpected issues as I am not also very familiar with the codes. So, I have to check all UT and ITs one by one. I think after the refactoring, developers who know the server module will be easy to understand the codes in the cluster module. And, once the ClusterIoTDB dominates the module, it will be clear to modify the startup process like using ID to replace Node. Best, ----------------------------------- Xiangdong Huang School of Software, Tsinghua University 黄向东 清华大学 软件学院
