Package io.microraft.report

Interface RaftNodeReport

public interface RaftNodeReport

Contains information about a Raft node's local state related to the execution of the Raft consensus algorithm.

Raft node reports are published either periodically or when there is a change in the local state of a Raft node related to the Raft consensus algorithm. The duration of the periodic report publishing is configured via RaftConfig.RaftConfigBuilder.setRaftNodeReportPublishPeriodSecs(int).

See Also:

RaftNodeReportListener, RaftConfig, RaftNodeReport.RaftNodeReportReason, RaftRole, RaftNodeStatus, RaftGroupMembers, RaftTerm, RaftLogStats

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	RaftNodeReport.RaftNodeReportReason	Denotes the reason for a given report

Method Summary

Modifier and Type	Method	Description
RaftGroupMembers	getCommittedMembers()	Returns the last committed member list of the Raft group this Raft node belongs to.
RaftGroupMembers	getEffectiveMembers()	Returns the currently effective member list of the Raft group this Raft node belongs to.
RaftEndpoint	getEndpoint()	Returns the local endpoint of the Raft node.
Object	getGroupId()	Returns the unique ID of the Raft group that this Raft node belongs to.
Map<RaftEndpoint,Long>	getHeartbeatTimestamps()	Returns timestamps of latest heartbeats sent by the non-leader nodes to the leader Raft node, including both RaftRole.FOLLOWER and RaftRole.LEARNER nodes.
RaftGroupMembers	getInitialMembers()	Returns the initial members of the Raft group this Raft node belongs to.
Optional<Long>	getLeaderHeartbeatTimestamp()	Returns timestamp of the latest heartbeat received from the leader Raft node.
RaftLogStats	getLog()	Returns statistics about a Raft node's local Raft log.
Optional<Long>	getQuorumHeartbeatTimestamp()	Returns earliest heartbeat timestamp of the replication quorum.
RaftNodeReport.RaftNodeReportReason	getReason()
RaftRole	getRole()	Returns the role of the Raft node in the current term.
RaftNodeStatus	getStatus()	Returns the status of the Raft node.
RaftTerm	getTerm()	Returns the locally known term information.

Method Detail

getReason

RaftNodeReport.RaftNodeReportReason getReason()

getGroupId

@Nonnull
Object getGroupId()

Returns the unique ID of the Raft group that this Raft node belongs to.

Returns:

the unique ID of the Raft group that this Raft node belongs to

getEndpoint

@Nonnull
RaftEndpoint getEndpoint()

Returns the local endpoint of the Raft node.

Returns:

the local endpoint of the Raft node

getInitialMembers

@Nonnull
RaftGroupMembers getInitialMembers()

Returns the initial members of the Raft group this Raft node belongs to.

Returns:

the initial members of the Raft group this Raft node belongs to

getCommittedMembers

@Nonnull
RaftGroupMembers getCommittedMembers()

Returns the last committed member list of the Raft group this Raft node belongs to.

Please note that the returned member list is read from the local state and can be different from the currently effective applied member list, if there is an ongoing (appended but not-yet committed) membership change in the group. It can be different from the current committed member list of the Raft group, also if a new membership change is committed by other Raft nodes of the group but not learnt by this Raft node yet.

Returns:

the last committed member list of the Raft group this Raft node belongs to

getEffectiveMembers

@Nonnull
RaftGroupMembers getEffectiveMembers()

Returns the currently effective member list of the Raft group this Raft node belongs to.

Please note that the returned member list is read from the local state and can be different from the committed member list, if there is an ongoing (appended but not-yet committed) membership change in the Raft group.

Returns:

the currently effective member list of the Raft group this Raft node belongs to

getRole

@Nonnull
RaftRole getRole()

Returns the role of the Raft node in the current term. If the returned role is RaftRole.LEADER, it means the local Raft node has received heartbeats from the majority in the last RaftConfig.leaderHeartbeatTimeoutSecs seconds.

Returns:

the role of the Raft node in the current term

getStatus

@Nonnull
RaftNodeStatus getStatus()

Returns the status of the Raft node.

Returns:

the status of the Raft node

getTerm

@Nonnull
RaftTerm getTerm()

Returns the locally known term information.

Please note that other nodes may have already switched to a higher term.

Returns:

the locally known term information

getLog

@Nonnull
RaftLogStats getLog()

Returns statistics about a Raft node's local Raft log.

Returns:

statistics about a Raft node's local Raft log

getHeartbeatTimestamps

@Nonnull
Map<RaftEndpoint,Long> getHeartbeatTimestamps()

Returns timestamps of latest heartbeats sent by the non-leader nodes to the leader Raft node, including both RaftRole.FOLLOWER and RaftRole.LEARNER nodes. The leader node's RaftEndpoint is not present in the map. This map is returned non-empty only by the leader Raft node.

Returns:

timestamps of latest heartbeats sent by the non-leader nodes

getQuorumHeartbeatTimestamp

@Nonnull
Optional<Long> getQuorumHeartbeatTimestamp()

Returns earliest heartbeat timestamp of the replication quorum. This method returns a non-empty value only for the leader Raft node. For instance, this method returns 8 for the following heartbeat timestamps of 5 Raft nodes, A (leader) ts = -, B (follower) ts = 10, C (follower) ts = 8, D (follower) ts = 6, E (follower) ts = 4. Please note that RaftRole.LEARNER nodes and their heartbeats are excluded in quorum calculations.

Returns:

earliest heartbeat timestamp of the replication quorum

getLeaderHeartbeatTimestamp

@Nonnull
Optional<Long> getLeaderHeartbeatTimestamp()

Returns timestamp of the latest heartbeat received from the leader Raft node. This method returns a non-empty value only from a non-leader Raft node if it has ever received a heartbeat from the leader.

Returns:

timestamp of the latest heartbeat received from the leader Raft node