[RATIS-1181] Define public APIs for StateMachine implementations

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Component/s: server, StateMachine
• Assignee: Tsz-wo Sze
• Reporter: Tsz-wo Sze
• Created: 26/Nov/20 02:17
• Updated: 01/Mar/21 01:48
• Resolved: 16/Dec/20 09:55

Description

StateMachine implementations such as Ozone need to access server methods such as RaftServerImpl.isLeader()/isLeaderReady(). We should define public APIs.

Issue Links

• is a parent of: RATIS-1192 Add a public API to get server states.
• is related to: HDDS-4517 Ozone should only use public Ratis APIs
• is related to: RATIS-1242 Move the public server APIs to a new module

Sub-Tasks

• Move RaftServerProxy/RaftServerImpl LOG to RaftServer: Resolved
• Add getId() and getPeer() to RaftServer/RaftServer.Division: Resolved
• Move RaftServerMetrics to org.apache.ratis.server.metrics: Resolved
• Avoid directly using RaftServerProxy in JvmPauseMonitor: Resolved
• Avoid directly using RaftServerImpl in LeaderElectionMetrics: Resolved
• Change MiniRaftCluster.getLeader() to return RaftServer.Division: Resolved
• Change other MiniRaftCluster methods to return RaftServer.Division: Resolved
• Remove the abstract newRaftServer method in MiniRaftCluster: Resolved
• Define an interface for FollowerInfo: Resolved
• Add a public API to get server states.: Resolved
• Add getRaftLog() to RaftServer.Division: Resolved
• Add getRoleInfoProto() and other methods to DivisionInfo: Resolved
• Change RaftServerProxy/RaftServerImpl to package private: Resolved
• Refactor LogAppender.SnapshotRequestIter: Resolved
• Change LogAppender to use RaftServer.Division and LeaderState: Resolved
• Separate LogAppender interface from the implementation: Resolved
• Expose RetryCache: Resolved
• Separate the default LogAppender implementation from LogAppenderBase: Resolved
• Define an interface for RaftConfiguration: Resolved
• Define a CallId class: Resolved
• Remove RaftServerConstants: Resolved
• RaftServerRpcWithProxy constructor and the abstract impl methods should be protected: Resolved
• Move out the LogEntryProto methods from ServerProtoUtils: Resolved
• Move the StateMachineData methods from ServerProtoUtils to LogProtoUtils: Resolved
• Move out the leader only methods from ServerProtoUtils: Resolved
• Move out the string method from ServerProtoUtils: Resolved
• Move the TermIndex implementation to TermIndex: Resolved