RaftNodeImpl (Hazelcast Root 4.0-BETA-1 API)

java.lang.Object
- com.hazelcast.cp.internal.raft.impl.RaftNodeImpl

All Implemented Interfaces:: RaftNode

public final class RaftNodeImpl
extends Object
implements RaftNode

Implementation of RaftNode.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`applyLogEntries()` Applies committed log entries between `lastApplied` and `commitIndex`, if there's any available.
`void`	`broadcastAppendRequest()` Broadcasts append-entries request to all group members according to their nextIndex parameters.
`boolean`	`canQueryLinearizable()` Returns true if a new query is currently allowed to be executed without appending to the Raft log.
`boolean`	`canReplicateNewEntry(Object operation)` Returns true if a new entry with the operation is currently allowed to be replicated.
`void`	`completeFuture(long entryIndex, Object response)` Completes the future registered with `entryIndex`.
`void`	`execute(Runnable task)` Executes task using `RaftIntegration.execute(Runnable)`.
`InternalCompletableFuture`	`forceSetTerminatedStatus()` Sets node's status to `RaftNodeStatus.TERMINATED` unconditionally if it's not terminated or stepped down yet.
`Collection<RaftEndpoint>`	`getAppliedMembers()` Returns the currently effective member list of the raft group this node belongs to.
`Collection<RaftEndpoint>`	`getCommittedMembers()` Returns the last committed member list of the raft group this node belongs to.
`CPGroupId`	`getGroupId()` Returns the groupId which this node belongs to.
`Collection<RaftEndpoint>`	`getInitialMembers()` Returns the initial member list of the Raft group this node belongs to.
`RaftEndpoint`	`getLeader()` Returns the known leader endpoint.
`long`	`getLeaderElectionTimeoutInMillis()` Returns a randomized leader election timeout in milliseconds based on configured timeout.
`RaftEndpoint`	`getLocalMember()` Returns the Raft endpoint for this node.
`ILogger`	`getLogger(Class clazz)`
`RaftNodeStatus`	`getStatus()` Returns the current status of this node.
`void`	`handleAppendRequest(AppendRequest request)` Handles `AppendRequest` sent by leader.
`void`	`handleAppendResponse(AppendFailureResponse response)` Handles `AppendFailureResponse` for a previously sent append request by this node.
`void`	`handleAppendResponse(AppendSuccessResponse response)` Handles `AppendSuccessResponse` for a previously sent append request by this node.
`void`	`handleInstallSnapshot(InstallSnapshot request)` Handles `InstallSnapshot` sent by leader.
`void`	`handlePreVoteRequest(PreVoteRequest request)` Handles `PreVoteRequest` sent by another follower.
`void`	`handlePreVoteResponse(PreVoteResponse response)` Handles `PreVoteResponse` for a previously sent request by this node.
`void`	`handleTriggerLeaderElection(TriggerLeaderElection request)`
`void`	`handleVoteRequest(VoteRequest request)` Handles `VoteRequest` sent by a candidate.
`void`	`handleVoteResponse(VoteResponse response)` Handles `VoteResponse` for a previously sent vote request by this node.
`boolean`	`installSnapshot(SnapshotEntry snapshot)` Restores the snapshot sent by the leader if it's not applied before.
`void`	`invalidateFuturesFrom(long entryIndex)` Invalidates futures registered with indexes `>= entryIndex`.
`boolean`	`isLinearizableReadOptimizationEnabled()` Returns true if the linearizable read optimization is enabled.
`boolean`	`isTerminatedOrSteppedDown()` Returns true if this node is `RaftNodeStatus.TERMINATED` or `RaftNodeStatus.STEPPED_DOWN`, false otherwise.
`long`	`lastAppendEntriesTimestamp()`
`void`	`leader(RaftEndpoint endpoint)` Updates the known leader endpoint and calls `RaftIntegration.onNodeStatusChange(RaftNodeStatus)`.
`static RaftNodeImpl`	`newRaftNode(CPGroupId groupId, RaftEndpoint localMember, Collection<RaftEndpoint> members, RaftAlgorithmConfig config, RaftIntegration integration)` Creates a new Raft node with an empty initial state.
`static RaftNodeImpl`	`newRaftNode(CPGroupId groupId, RaftEndpoint localMember, Collection<RaftEndpoint> members, RaftAlgorithmConfig config, RaftIntegration integration, RaftStateStore raftStateStore)` Creates a new Raft node with an empty initial state and a `RaftStateStore` to persist Raft state changes
`void`	`printMemberState()`
`InternalCompletableFuture`	`query(Object operation, QueryPolicy queryPolicy)` Executes the given operation on Raft group depending on the `QueryPolicy`
`void`	`registerFuture(long entryIndex, InternalCompletableFuture future)` Registers the future for the appended entry with its `entryIndex`.
`InternalCompletableFuture`	`replicate(Object operation)` Replicates the given operation to the Raft group.
`InternalCompletableFuture`	`replicateMembershipChange(RaftEndpoint member, MembershipChangeMode mode)` Replicates the membership change to the Raft group.
`InternalCompletableFuture`	`replicateMembershipChange(RaftEndpoint member, MembershipChangeMode mode, long groupMembersCommitIndex)` Replicates the membership change to the Raft group, if expected members commit index is equal to the actual one stored in Raft state.
`void`	`resetGroupMembers()` Resets Raft group members back.
`static RaftNodeImpl`	`restoreRaftNode(CPGroupId groupId, RestoredRaftState restoredState, RaftAlgorithmConfig config, RaftIntegration integration)` Creates a new Raft node with restored Raft state
`static RaftNodeImpl`	`restoreRaftNode(CPGroupId groupId, RestoredRaftState restoredState, RaftAlgorithmConfig config, RaftIntegration integration, RaftStateStore raftStateStore)` Creates a new Raft node with restored Raft state and a `RaftStateStore` to persist Raft state changes
`void`	`runQuery(Object operation, InternalCompletableFuture resultFuture)` Executes query operation sets execution result to the future.
`void`	`schedule(Runnable task, long delayInMillis)` Schedules task using `RaftIntegration.schedule(Runnable, long, TimeUnit)`.
`void`	`send(AppendFailureResponse response, RaftEndpoint target)`
`void`	`send(AppendSuccessResponse response, RaftEndpoint target)`
`void`	`send(PreVoteRequest request, RaftEndpoint target)`
`void`	`send(PreVoteResponse response, RaftEndpoint target)`
`void`	`send(TriggerLeaderElection request, RaftEndpoint target)`
`void`	`send(VoteRequest request, RaftEndpoint target)`
`void`	`send(VoteResponse response, RaftEndpoint target)`
`void`	`sendAppendRequest(RaftEndpoint follower)` Sends an append-entries request to the follower member.
`void`	`setStatus(RaftNodeStatus newStatus)`
`void`	`start()` Starts the periodic tasks, such as voting, leader failure-detection, snapshot handling.
`RaftState`	`state()`
`void`	`toFollower(int term)` Switches this node to follower role by clearing the known leader endpoint and (pre) candidate states, and updating the term.
`void`	`toLeader()` Switches this Raft node to the leader role by performing the following steps: Setting the local endpoint as the current leader, Clearing (pre)candidate states, Initializing the leader state for the current members, Appending an operation to the Raft log if enabled, Scheduling the periodic heartbeat task, Printing the member state.
`String`	`toString()`
`InternalCompletableFuture`	`transferLeadership(RaftEndpoint endpoint)` Transfers group leadership to the given endpoint, if the local Raft node is the leader with ACTIVE status and the endpoint is a group member.
`boolean`	`tryAdvanceCommitIndex()`
`boolean`	`tryRunQueries()`
`void`	`updateGroupMembers(long logIndex, Collection<RaftEndpoint> members)` Updates Raft group members.
`void`	`updateLastAppendEntriesTimestamp()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Method Detail
  - newRaftNode
```
public static RaftNodeImpl newRaftNode(CPGroupId groupId,
                                       RaftEndpoint localMember,
                                       Collection<RaftEndpoint> members,
                                       RaftAlgorithmConfig config,
                                       RaftIntegration integration)
```
    Creates a new Raft node with an empty initial state.
  - newRaftNode
```
public static RaftNodeImpl newRaftNode(CPGroupId groupId,
                                       RaftEndpoint localMember,
                                       Collection<RaftEndpoint> members,
                                       RaftAlgorithmConfig config,
                                       RaftIntegration integration,
                                       RaftStateStore raftStateStore)
```
    Creates a new Raft node with an empty initial state and a RaftStateStore to persist Raft state changes
  - restoreRaftNode
```
public static RaftNodeImpl restoreRaftNode(CPGroupId groupId,
                                           RestoredRaftState restoredState,
                                           RaftAlgorithmConfig config,
                                           RaftIntegration integration)
```
    Creates a new Raft node with restored Raft state
  - restoreRaftNode
```
public static RaftNodeImpl restoreRaftNode(CPGroupId groupId,
                                           RestoredRaftState restoredState,
                                           RaftAlgorithmConfig config,
                                           RaftIntegration integration,
                                           RaftStateStore raftStateStore)
```
    Creates a new Raft node with restored Raft state and a RaftStateStore to persist Raft state changes
  - getLogger
```
public ILogger getLogger(Class clazz)
```
  - getGroupId
```
public CPGroupId getGroupId()
```
    Description copied from interface: RaftNode
    
    Returns the groupId which this node belongs to.
    
    Specified by:
    
    getGroupId in interface RaftNode
  - getLocalMember
```
public RaftEndpoint getLocalMember()
```
    Description copied from interface: RaftNode
    
    Returns the Raft endpoint for this node.
    
    Specified by:
    
    getLocalMember in interface RaftNode
  - getLeader
```
public RaftEndpoint getLeader()
```
    Description copied from interface: RaftNode
    
    Returns the known leader endpoint. Leader endpoint might be already changed when this method returns.
    
    Specified by:
    
    getLeader in interface RaftNode
  - getStatus
```
public RaftNodeStatus getStatus()
```
    Description copied from interface: RaftNode
    
    Returns the current status of this node.
    
    Specified by:
    
    getStatus in interface RaftNode
  - getInitialMembers
```
public Collection<RaftEndpoint> getInitialMembers()
```
    Description copied from interface: RaftNode
    
    Returns the initial member list of the Raft group this node belongs to.
    
    Specified by:
    
    getInitialMembers in interface RaftNode
  - getCommittedMembers
```
public Collection<RaftEndpoint> getCommittedMembers()
```
    Description copied from interface: RaftNode
    
    Returns the last committed member list of the raft group this node belongs to. Please note that the returned member list can be different from the currently effective member list, if there is an ongoing membership change in the group.
    
    Specified by:
    
    getCommittedMembers in interface RaftNode
  - getAppliedMembers
```
public Collection<RaftEndpoint> getAppliedMembers()
```
    Description copied from interface: RaftNode
    
    Returns the currently effective member list of the raft group this node belongs to. Please note that the returned member list can be different from the committed member list, if there is an ongoing membership change in the group.
    
    Specified by:
    
    getAppliedMembers in interface RaftNode
  - forceSetTerminatedStatus
```
public InternalCompletableFuture forceSetTerminatedStatus()
```
    Description copied from interface: RaftNode
    
    Sets node's status to RaftNodeStatus.TERMINATED unconditionally if it's not terminated or stepped down yet.
    
    Specified by:
    
    forceSetTerminatedStatus in interface RaftNode
  - start
```
public void start()
```
    Starts the periodic tasks, such as voting, leader failure-detection, snapshot handling.
  - handlePreVoteRequest
```
public void handlePreVoteRequest(PreVoteRequest request)
```
    Description copied from interface: RaftNode
    
    Handles PreVoteRequest sent by another follower.
    
    Specified by:
    
    handlePreVoteRequest in interface RaftNode
  - handlePreVoteResponse
```
public void handlePreVoteResponse(PreVoteResponse response)
```
    Description copied from interface: RaftNode
    
    Handles PreVoteResponse for a previously sent request by this node.
    
    Specified by:
    
    handlePreVoteResponse in interface RaftNode
  - handleVoteRequest
```
public void handleVoteRequest(VoteRequest request)
```
    Description copied from interface: RaftNode
    
    Handles VoteRequest sent by a candidate.
    
    Specified by:
    
    handleVoteRequest in interface RaftNode
  - handleVoteResponse
```
public void handleVoteResponse(VoteResponse response)
```
    Description copied from interface: RaftNode
    
    Handles VoteResponse for a previously sent vote request by this node.
    
    Specified by:
    
    handleVoteResponse in interface RaftNode
  - handleAppendRequest
```
public void handleAppendRequest(AppendRequest request)
```
    Description copied from interface: RaftNode
    
    Handles AppendRequest sent by leader.
    
    Specified by:
    
    handleAppendRequest in interface RaftNode
  - handleAppendResponse
```
public void handleAppendResponse(AppendSuccessResponse response)
```
    Description copied from interface: RaftNode
    
    Handles AppendSuccessResponse for a previously sent append request by this node.
    
    Specified by:
    
    handleAppendResponse in interface RaftNode
  - handleAppendResponse
```
public void handleAppendResponse(AppendFailureResponse response)
```
    Description copied from interface: RaftNode
    
    Handles AppendFailureResponse for a previously sent append request by this node.
    
    Specified by:
    
    handleAppendResponse in interface RaftNode
  - handleInstallSnapshot
```
public void handleInstallSnapshot(InstallSnapshot request)
```
    Description copied from interface: RaftNode
    
    Handles InstallSnapshot sent by leader.
    
    Specified by:
    
    handleInstallSnapshot in interface RaftNode
  - handleTriggerLeaderElection
```
public void handleTriggerLeaderElection(TriggerLeaderElection request)
```
    Specified by:
    
    handleTriggerLeaderElection in interface RaftNode
  - replicate
```
public InternalCompletableFuture replicate(Object operation)
```
    Description copied from interface: RaftNode
    
    Replicates the given operation to the Raft group. Only the leader can process replicate requests.
    Otherwise, if this node is not leader, or the leader is demoted before committing the operation, the returned future is notified with a related exception.
    
    Specified by:
    
    replicate in interface RaftNode
    
    Parameters:
    
    operation - operation to replicate
    
    Returns:
    
    future to get notified about result of the replication
  - replicateMembershipChange
```
public InternalCompletableFuture replicateMembershipChange(RaftEndpoint member,
                                                           MembershipChangeMode mode)
```
    Description copied from interface: RaftNode
    
    Replicates the membership change to the Raft group. Only the leader can process membership change requests.
    If this node is not leader, or the leader is demoted before committing the operation, or membership change is not committed for any reason, then the returned future is notified with a related exception.
    
    Specified by:
    
    replicateMembershipChange in interface RaftNode
    
    Parameters:
    
    member - member to add or remove
    
    mode - type of membership change
    
    Returns:
    
    future to get notified about result of the membership change
  - replicateMembershipChange
```
public InternalCompletableFuture replicateMembershipChange(RaftEndpoint member,
                                                           MembershipChangeMode mode,
                                                           long groupMembersCommitIndex)
```
    Description copied from interface: RaftNode
    
    Replicates the membership change to the Raft group, if expected members commit index is equal to the actual one stored in Raft state. Otherwise, fails with MismatchingGroupMembersCommitIndexException.
    For more info see RaftNode.replicate(Object).
    
    Specified by:
    
    replicateMembershipChange in interface RaftNode
    
    Parameters:
    
    member - member to add or remove
    
    mode - type of membership change
    
    groupMembersCommitIndex - expected members commit index
    
    Returns:
    
    future to get notified about result of the membership change
  - query
```
public InternalCompletableFuture query(Object operation,
                                       QueryPolicy queryPolicy)
```
    Description copied from interface: RaftNode
    
    Executes the given operation on Raft group depending on the QueryPolicy
    
    Specified by:
    
    query in interface RaftNode
    
    Parameters:
    
    operation - operation to query
    
    queryPolicy - query policy to decide where to execute operation
    
    Returns:
    
    future to get notified about result of the query
  - transferLeadership
```
public InternalCompletableFuture transferLeadership(RaftEndpoint endpoint)
```
    Description copied from interface: RaftNode
    
    Transfers group leadership to the given endpoint, if the local Raft node is the leader with ACTIVE status and the endpoint is a group member.
    Leadership transfer is considered to be completed when the local Raft node moves to a term that is bigger than its current term, and there is no strict guarantee that the given endpoint will be the new leader. However, it is very likely that the given endpoint will become the new leader.
    The local Raft node will not replicate any new entry during a leadership transfer and new calls to the RaftNode.replicate(Object) method will fail with CannotReplicateException.
    
    Specified by:
    
    transferLeadership in interface RaftNode
    
    Returns:
    
    future to get notified about result of the leadership transfer
  - isTerminatedOrSteppedDown
```
public boolean isTerminatedOrSteppedDown()
```
    Description copied from interface: RaftNode
    Returns true if this node is RaftNodeStatus.TERMINATED or RaftNodeStatus.STEPPED_DOWN, false otherwise.
    This method is essentially same as;
```
 
     return status == TERMINATED || status == STEPPED_DOWN
 
 
```
    Specified by:
    
    isTerminatedOrSteppedDown in interface RaftNode
  - setStatus
```
public void setStatus(RaftNodeStatus newStatus)
```
  - getLeaderElectionTimeoutInMillis
```
public long getLeaderElectionTimeoutInMillis()
```
    Returns a randomized leader election timeout in milliseconds based on configured timeout.
    
    See Also:
    
    RaftAlgorithmConfig.getLeaderElectionTimeoutInMillis()
  - canReplicateNewEntry
```
public boolean canReplicateNewEntry(Object operation)
```
    Returns true if a new entry with the operation is currently allowed to be replicated. This method can be invoked only when the local Raft node is the leader.
    Replication is not allowed, when;
    - Node is terminating, terminated or stepped down. See RaftNodeStatus.
    - Raft log contains max allowed uncommitted entry count. See RaftAlgorithmConfig.getUncommittedEntryCountToRejectNewAppends().
    - The operation is a RaftGroupCmd and there's an ongoing membership change in group.
    - The operation is a membership change operation and there's no committed entry in this term yet. See RaftIntegration.getAppendedEntryOnLeaderElection().
    - There is an ongoing leadership transfer.
  - canQueryLinearizable
```
public boolean canQueryLinearizable()
```
    Returns true if a new query is currently allowed to be executed without appending to the Raft log. This method can be invoked only when the local Raft node is the leader.
    A new linearizable query execution is not allowed, when;
    - Node is terminating, terminated or stepped down. See RaftNodeStatus.
    - If the leader has not yet marked an entry from its current term committed. See Section 6.4 of Raft Dissertation.
    - There are already RaftAlgorithmConfig.getUncommittedEntryCountToRejectNewAppends() queries waiting to be executed.
  - isLinearizableReadOptimizationEnabled
```
public boolean isLinearizableReadOptimizationEnabled()
```
    Returns true if the linearizable read optimization is enabled.
  - send
```
public void send(PreVoteRequest request,
                 RaftEndpoint target)
```
  - send
```
public void send(PreVoteResponse response,
                 RaftEndpoint target)
```
  - send
```
public void send(VoteRequest request,
                 RaftEndpoint target)
```
  - send
```
public void send(VoteResponse response,
                 RaftEndpoint target)
```
  - send
```
public void send(AppendSuccessResponse response,
                 RaftEndpoint target)
```
  - send
```
public void send(AppendFailureResponse response,
                 RaftEndpoint target)
```
  - send
```
public void send(TriggerLeaderElection request,
                 RaftEndpoint target)
```
  - broadcastAppendRequest
```
public void broadcastAppendRequest()
```
    Broadcasts append-entries request to all group members according to their nextIndex parameters.
  - sendAppendRequest
```
public void sendAppendRequest(RaftEndpoint follower)
```
    Sends an append-entries request to the follower member.
    Log entries between follower's known nextIndex and latest appended entry index are sent in a batch. Batch size can be RaftAlgorithmConfig.getAppendRequestMaxEntryCount() at most.
    If follower's nextIndex is behind the latest snapshot index, then InstallSnapshot request is sent.
    If leader doesn't know follower's matchIndex (if matchIndex == 0), then an empty append-entries is sent to save bandwidth until leader learns the matchIndex of the follower.
  - applyLogEntries
```
public void applyLogEntries()
```
    Applies committed log entries between lastApplied and commitIndex, if there's any available. If new entries are applied, RaftState's lastApplied field is updated.
    
    See Also:
    
    RaftState.lastApplied(), RaftState.commitIndex()
  - updateLastAppendEntriesTimestamp
```
public void updateLastAppendEntriesTimestamp()
```
  - lastAppendEntriesTimestamp
```
public long lastAppendEntriesTimestamp()
```
  - state
```
public RaftState state()
```
  - runQuery
```
public void runQuery(Object operation,
                     InternalCompletableFuture resultFuture)
```
    Executes query operation sets execution result to the future.
  - execute
```
public void execute(Runnable task)
```
    Executes task using RaftIntegration.execute(Runnable).
  - schedule
```
public void schedule(Runnable task,
                     long delayInMillis)
```
    Schedules task using RaftIntegration.schedule(Runnable, long, TimeUnit).
  - registerFuture
```
public void registerFuture(long entryIndex,
                           InternalCompletableFuture future)
```
    Registers the future for the appended entry with its entryIndex.
  - completeFuture
```
public void completeFuture(long entryIndex,
                           Object response)
```
    Completes the future registered with entryIndex.
  - invalidateFuturesFrom
```
public void invalidateFuturesFrom(long entryIndex)
```
    Invalidates futures registered with indexes >= entryIndex. Note that entryIndex is inclusive. LeaderDemotedException is set a result to futures.
  - installSnapshot
```
public boolean installSnapshot(SnapshotEntry snapshot)
```
    Restores the snapshot sent by the leader if it's not applied before.
    
    Returns:
    
    true if snapshot is restored, false otherwise.
  - printMemberState
```
public void printMemberState()
```
  - updateGroupMembers
```
public void updateGroupMembers(long logIndex,
                               Collection<RaftEndpoint> members)
```
    Updates Raft group members.
    
    See Also:
    
    RaftState.updateGroupMembers(long, Collection)
  - resetGroupMembers
```
public void resetGroupMembers()
```
    Resets Raft group members back.
    
    See Also:
    
    RaftState.resetGroupMembers()
  - toFollower
```
public void toFollower(int term)
```
    Switches this node to follower role by clearing the known leader endpoint and (pre) candidate states, and updating the term. If this Raft node was leader before switching to the follower state, it may have some queries waiting to be executed. Those queries are also failed with LeaderDemotedException. After the state switch, RaftIntegration.onNodeStatusChange(RaftNodeStatus) is called.
    
    Parameters:
    
    term - the new term to switch
  - leader
```
public void leader(RaftEndpoint endpoint)
```
    Updates the known leader endpoint and calls RaftIntegration.onNodeStatusChange(RaftNodeStatus).
    
    Parameters:
    
    endpoint - the new leader endpoint
  - toLeader
```
public void toLeader()
```
    Switches this Raft node to the leader role by performing the following steps:
    - Setting the local endpoint as the current leader,
    - Clearing (pre)candidate states,
    - Initializing the leader state for the current members,
    - Appending an operation to the Raft log if enabled,
    - Scheduling the periodic heartbeat task,
    - Printing the member state.
  - tryAdvanceCommitIndex
```
public boolean tryAdvanceCommitIndex()
```
  - tryRunQueries
```
public boolean tryRunQueries()
```
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class RaftNodeImpl

Method Summary

Methods inherited from class java.lang.Object

Method Detail

newRaftNode

newRaftNode

restoreRaftNode

restoreRaftNode

getLogger

getGroupId

getLocalMember

getLeader

getStatus

getInitialMembers

getCommittedMembers

getAppliedMembers

forceSetTerminatedStatus

start

handlePreVoteRequest

handlePreVoteResponse

handleVoteRequest

handleVoteResponse

handleAppendRequest

handleAppendResponse

handleAppendResponse

handleInstallSnapshot

handleTriggerLeaderElection

replicate

replicateMembershipChange

replicateMembershipChange

query

transferLeadership

isTerminatedOrSteppedDown

setStatus

getLeaderElectionTimeoutInMillis

canReplicateNewEntry

canQueryLinearizable

isLinearizableReadOptimizationEnabled

send

send

send

send

send

send

send

broadcastAppendRequest

sendAppendRequest

applyLogEntries

updateLastAppendEntriesTimestamp

lastAppendEntriesTimestamp

state

runQuery

execute

schedule

registerFuture

completeFuture

invalidateFuturesFrom

installSnapshot

printMemberState

updateGroupMembers

resetGroupMembers

toFollower

leader

toLeader

tryAdvanceCommitIndex

tryRunQueries

toString