Node (jraft-core 1.3.8 1.3.8 API)

所有超级接口:

Describer, Lifecycle<NodeOptions>

所有已知实现类:

NodeImpl
```
public interface Node
extends Lifecycle<NodeOptions>, Describer
```
A raft replica node.

作者:

boyan (boyan@alibaba-inc.com) 2018-Apr-03 4:06:55 PM

嵌套类概要
- 从接口继承的嵌套类/接口 com.alipay.sofa.jraft.util.Describer
  Describer.DefaultPrinter, Describer.Printer

方法概要

所有方法实例方法抽象方法
限定符和类型	方法和说明
`void`	`addLearners(List<PeerId> learners, Closure done)` Add some new learners to the raft group. done.run() will be invoked after this operation finishes, describing the detailed result.
`void`	`addPeer(PeerId peer, Closure done)` Add a new peer to the raft group. done.run() would be invoked after this operation finishes, describing the detailed result.
`void`	`addReplicatorStateListener(Replicator.ReplicatorStateListener replicatorStateListener)` SOFAJRaft users can implement the ReplicatorStateListener interface by themselves.
`void`	`apply(Task task)` [Thread-safe and wait-free] Apply task to the replicated-state-machine About the ownership: \|task.data\|: for the performance consideration, we will take away the content.
`void`	`changePeers(Configuration newPeers, Closure done)` Change the configuration of the raft group to \|newPeers\| , done.un() would be invoked after this operation finishes, describing the detailed result.
`void`	`clearReplicatorStateListeners()` Remove all the ReplicatorStateListeners which have been added by users.
`String`	`getGroupId()` Get the raft group id.
`PeerId`	`getLeaderId()` Get the leader peer id for redirect, null if absent.
`NodeId`	`getNodeId()` Get current node id.
`NodeMetrics`	`getNodeMetrics()` Get the node metrics, only valid when node option `NodeOptions.isEnableMetrics()` is true.
`State`	`getNodeState()` Get the node's state.
`int`	`getNodeTargetPriority()` Get the node's target election priority value.
`NodeOptions`	`getOptions()` Get the node options.
`RaftOptions`	`getRaftOptions()` Get the raft options
`List<Replicator.ReplicatorStateListener>`	`getReplicatorStatueListeners()` Get the ReplicatorStateListeners which have been added by users.
`boolean`	`isLeader()` Returns true when the node is leader.
`boolean`	`isLeader(boolean blocking)` Returns true when the node is leader.
`void`	`join()` Block the thread until the node is successfully stopped.
`List<PeerId>`	`listAliveLearners()` List all alive learners of this raft group, only leader returns.
`List<PeerId>`	`listAlivePeers()` List all alive peers of this raft group, only leader returns.
`List<PeerId>`	`listLearners()` List all learners of this raft group, only leader returns.
`List<PeerId>`	`listPeers()` List peers of this raft group, only leader returns.
`UserLog`	`readCommittedUserLog(long index)` Read the first committed user log from the given index.
`void`	`readIndex(byte[] requestContext, ReadIndexClosure done)` [Thread-safe and wait-free] Starts a linearizable read-only query request with request context(optional, such as request id etc.) and closure.
`void`	`removeLearners(List<PeerId> learners, Closure done)` Remove some learners from the raft group. done.run() will be invoked after this operation finishes, describing the detailed result.
`void`	`removePeer(PeerId peer, Closure done)` Remove the peer from the raft group. done.run() would be invoked after operation finishes, describing the detailed result.
`void`	`removeReplicatorStateListener(Replicator.ReplicatorStateListener replicatorStateListener)` End User can remove their implement the ReplicatorStateListener interface by themselves.
`void`	`resetElectionTimeoutMs(int electionTimeoutMs)` Reset the election_timeout for the every node.
`void`	`resetLearners(List<PeerId> learners, Closure done)` Reset learners in the raft group. done.run() will be invoked after this operation finishes, describing the detailed result.
`Status`	`resetPeers(Configuration newPeers)` Reset the configuration of this node individually, without any replication to other peers before this node becomes the leader.
`void`	`shutdown(Closure done)` Shutdown local replica node.
`void`	`snapshot(Closure done)` Start a snapshot immediately if possible. done.run() would be invoked when the snapshot finishes, describing the detailed result.
`Status`	`transferLeadershipTo(PeerId peer)` Try transferring leadership to \|peer\|.

从接口继承的方法 com.alipay.sofa.jraft.Lifecycle
init, shutdown

从接口继承的方法 com.alipay.sofa.jraft.util.Describer
describe

- 方法详细资料
  - getLeaderId
```
PeerId getLeaderId()
```
    Get the leader peer id for redirect, null if absent.
  - getNodeId
```
NodeId getNodeId()
```
    Get current node id.
  - getNodeMetrics
```
NodeMetrics getNodeMetrics()
```
    Get the node metrics, only valid when node option NodeOptions.isEnableMetrics() is true.
  - getGroupId
```
String getGroupId()
```
    Get the raft group id.
  - getOptions
```
NodeOptions getOptions()
```
    Get the node options.
  - getRaftOptions
```
RaftOptions getRaftOptions()
```
    Get the raft options
  - isLeader
```
boolean isLeader()
```
    Returns true when the node is leader.
  - isLeader
```
boolean isLeader(boolean blocking)
```
    Returns true when the node is leader.
    
    参数:
    
    blocking - if true, will be blocked until the node finish it's state change
  - shutdown
```
void shutdown(Closure done)
```
    Shutdown local replica node.
    
    参数:
    
    done - callback
  - join
```
void join()
   throws InterruptedException
```
    Block the thread until the node is successfully stopped.
    
    抛出:
    
    InterruptedException - if the current thread is interrupted while waiting
  - apply
```
void apply(Task task)
```
    [Thread-safe and wait-free] Apply task to the replicated-state-machine About the ownership: |task.data|: for the performance consideration, we will take away the content. If you want keep the content, copy it before call this function |task.done|: If the data is successfully committed to the raft group. We will pass the ownership to #StateMachine.onApply(Iterator). Otherwise we will specify the error and call it.
    
    参数:
    
    task - task to apply
  - readIndex
```
void readIndex(byte[] requestContext,
               ReadIndexClosure done)
```
    [Thread-safe and wait-free] Starts a linearizable read-only query request with request context(optional, such as request id etc.) and closure. The closure will be called when the request is completed, and user can read data from state machine if the result status is OK.
    
    参数:
    
    requestContext - the context of request
    
    done - callback
    
    从以下版本开始:
    
    0.0.3
  - listPeers
```
List<PeerId> listPeers()
```
    List peers of this raft group, only leader returns. [NOTE] when list_peers concurrency with addPeer(PeerId, Closure)/removePeer(PeerId, Closure), maybe return peers is staled. Because addPeer(PeerId, Closure)/removePeer(PeerId, Closure) immediately modify configuration in memory
    
    返回:
    
    the peer list
  - listAlivePeers
```
List<PeerId> listAlivePeers()
```
    List all alive peers of this raft group, only leader returns.
    [NOTE] list_alive_peers is just a transient data (snapshot) and a short-term loss of response by the follower will cause it to temporarily not exist in this list.
    
    返回:
    
    the alive peer list
    
    从以下版本开始:
    
    1.2.6
  - listLearners
```
List<PeerId> listLearners()
```
    List all learners of this raft group, only leader returns.
    [NOTE] when listLearners concurrency with addLearners(List, Closure)/removeLearners(List, Closure)/resetLearners(List, Closure), maybe return peers is staled. Because addLearners(List, Closure)/removeLearners(List, Closure)/resetLearners(List, Closure) immediately modify configuration in memory
    
    返回:
    
    the learners set
    
    从以下版本开始:
    
    1.3.0
  - listAliveLearners
```
List<PeerId> listAliveLearners()
```
    List all alive learners of this raft group, only leader returns.
    [NOTE] when listAliveLearners concurrency with addLearners(List, Closure)/removeLearners(List, Closure)/resetLearners(List, Closure), maybe return peers is staled. Because addLearners(List, Closure)/removeLearners(List, Closure)/resetLearners(List, Closure) immediately modify configuration in memory
    
    返回:
    
    the alive learners set
    
    从以下版本开始:
    
    1.3.0
  - addPeer
```
void addPeer(PeerId peer,
             Closure done)
```
    Add a new peer to the raft group. done.run() would be invoked after this operation finishes, describing the detailed result.
    
    参数:
    
    peer - peer to add
    
    done - callback
  - removePeer
```
void removePeer(PeerId peer,
                Closure done)
```
    Remove the peer from the raft group. done.run() would be invoked after operation finishes, describing the detailed result.
    
    参数:
    
    peer - peer to remove
    
    done - callback
  - changePeers
```
void changePeers(Configuration newPeers,
                 Closure done)
```
    Change the configuration of the raft group to |newPeers| , done.un() would be invoked after this operation finishes, describing the detailed result.
    
    参数:
    
    newPeers - new peers to change
    
    done - callback
  - resetPeers
```
Status resetPeers(Configuration newPeers)
```
    Reset the configuration of this node individually, without any replication to other peers before this node becomes the leader. This function is supposed to be invoked when the majority of the replication group are dead and you'd like to revive the service in the consideration of availability. Notice that neither consistency nor consensus are guaranteed in this case, BE CAREFULE when dealing with this method.
    
    参数:
    
    newPeers - new peers
  - addLearners
```
void addLearners(List<PeerId> learners,
                 Closure done)
```
    Add some new learners to the raft group. done.run() will be invoked after this operation finishes, describing the detailed result.
    
    参数:
    
    learners - learners to add
    
    done - callback
    
    从以下版本开始:
    
    1.3.0
  - removeLearners
```
void removeLearners(List<PeerId> learners,
                    Closure done)
```
    Remove some learners from the raft group. done.run() will be invoked after this operation finishes, describing the detailed result.
    
    参数:
    
    learners - learners to remove
    
    done - callback
    
    从以下版本开始:
    
    1.3.0
  - resetLearners
```
void resetLearners(List<PeerId> learners,
                   Closure done)
```
    Reset learners in the raft group. done.run() will be invoked after this operation finishes, describing the detailed result.
    
    参数:
    
    learners - learners to set
    
    done - callback
    
    从以下版本开始:
    
    1.3.0
  - snapshot
```
void snapshot(Closure done)
```
    Start a snapshot immediately if possible. done.run() would be invoked when the snapshot finishes, describing the detailed result.
    
    参数:
    
    done - callback
  - resetElectionTimeoutMs
```
void resetElectionTimeoutMs(int electionTimeoutMs)
```
    Reset the election_timeout for the every node.
    
    参数:
    
    electionTimeoutMs - the timeout millis of election
  - transferLeadershipTo
```
Status transferLeadershipTo(PeerId peer)
```
    Try transferring leadership to |peer|. If peer is ANY_PEER, a proper follower will be chosen as the leader for the next term. Returns 0 on success, -1 otherwise.
    
    参数:
    
    peer - the target peer of new leader
    
    返回:
    
    operation status
  - readCommittedUserLog
```
UserLog readCommittedUserLog(long index)
```
    Read the first committed user log from the given index. Return OK on success and user_log is assigned with the very data. Be awared that the user_log may be not the exact log at the given index, but the first available user log from the given index to lastCommittedIndex. Otherwise, appropriate errors are returned: - return ELOGDELETED when the log has been deleted; - return ENOMOREUSERLOG when we can't get a user log even reaching lastCommittedIndex. [NOTE] in consideration of safety, we use lastAppliedIndex instead of lastCommittedIndex in code implementation.
    
    参数:
    
    index - log index
    
    返回:
    
    user log entry
    
    抛出:
    
    LogNotFoundException - the user log is deleted at index.
    
    LogIndexOutOfBoundsException - the special index is out of bounds.
  - addReplicatorStateListener
```
void addReplicatorStateListener(Replicator.ReplicatorStateListener replicatorStateListener)
```
    SOFAJRaft users can implement the ReplicatorStateListener interface by themselves. So users can do their own logical operator in this listener when replicator created, destroyed or had some errors.
    
    参数:
    
    replicatorStateListener - added ReplicatorStateListener which is implemented by users.
  - removeReplicatorStateListener
```
void removeReplicatorStateListener(Replicator.ReplicatorStateListener replicatorStateListener)
```
    End User can remove their implement the ReplicatorStateListener interface by themselves.
    
    参数:
    
    replicatorStateListener - need to remove the ReplicatorStateListener which has been added by users.
  - clearReplicatorStateListeners
```
void clearReplicatorStateListeners()
```
    Remove all the ReplicatorStateListeners which have been added by users.
  - getReplicatorStatueListeners
```
List<Replicator.ReplicatorStateListener> getReplicatorStatueListeners()
```
    Get the ReplicatorStateListeners which have been added by users.
    
    返回:
    
    node's replicatorStatueListeners which have been added by users.
  - getNodeTargetPriority
```
int getNodeTargetPriority()
```
    Get the node's target election priority value.
    
    返回:
    
    node's target election priority value.
    
    从以下版本开始:
    
    1.3.0
  - getNodeState
```
State getNodeState()
```
    Get the node's state.
    
    返回:
    
    node's state.
    
    从以下版本开始:
    
    1.3.8

接口 Node

嵌套类概要

从接口继承的嵌套类/接口 com.alipay.sofa.jraft.util.Describer

方法概要

从接口继承的方法 com.alipay.sofa.jraft.Lifecycle

从接口继承的方法 com.alipay.sofa.jraft.util.Describer

方法详细资料

getLeaderId

getNodeId

getNodeMetrics

getGroupId

getOptions

getRaftOptions

isLeader

isLeader

shutdown

join

apply

readIndex

listPeers

listAlivePeers

listLearners

listAliveLearners

addPeer

removePeer

changePeers

resetPeers

addLearners

removeLearners

resetLearners

snapshot

resetElectionTimeoutMs

transferLeadershipTo

readCommittedUserLog

addReplicatorStateListener

removeReplicatorStateListener

clearReplicatorStateListeners

getReplicatorStatueListeners

getNodeTargetPriority

getNodeState