org.apache.hadoop.hbase.regionserver

类 SplitLogWorker

java.lang.Object

org.apache.hadoop.hbase.regionserver.SplitLogWorker

所有已实现的接口:

Runnable

@InterfaceAudience.Private
public class SplitLogWorker
extends Object
implements Runnable

This worker is spawned in every regionserver, including master. The Worker waits for log splitting tasks to be put up by the SplitLogManager running in the master and races with other workers in other serves to acquire those tasks. The coordination is done via coordination engine.

If a worker has successfully moved the task from state UNASSIGNED to OWNED then it owns the task. It keeps heart beating the manager by periodically moving the task from UNASSIGNED to OWNED state. On success it moves the task to TASK_DONE. On unrecoverable error it moves task state to ERR. If it cannot continue but wants the master to retry the task then it moves the task state to RESIGNED.

The manager can take a task away from a worker by moving the task from OWNED to UNASSIGNED. In the absence of a global lock there is a unavoidable race here - a worker might have just finished its task when it is stripped of its ownership. Here we rely on the idempotency of the log splitting task for correctness

嵌套类概要

嵌套类

限定符和类型	类和说明
static interface	SplitLogWorker.TaskExecutor Objects implementing this interface actually do the task that has been acquired by a SplitLogWorker.

构造器概要

构造器

构造器和说明
SplitLogWorker(Server hserver, org.apache.hadoop.conf.Configuration conf, RegionServerServices server, LastSequenceId sequenceIdChecker, WALFactory factory)
SplitLogWorker(Server hserver, org.apache.hadoop.conf.Configuration conf, RegionServerServices server, SplitLogWorker.TaskExecutor splitTaskExecutor)

方法概要

限定符和类型	方法和说明
int	getTaskReadySeq() Returns the number of tasks processed by coordination.
void	run()
void	start() start the SplitLogWorker thread
void	stop() stop the SplitLogWorker thread
void	stopTask() If the worker is doing a task i.e. splitting a log file then stop the task.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

SplitLogWorker

public SplitLogWorker(Server hserver,
                      org.apache.hadoop.conf.Configuration conf,
                      RegionServerServices server,
                      SplitLogWorker.TaskExecutor splitTaskExecutor)

SplitLogWorker

public SplitLogWorker(Server hserver,
                      org.apache.hadoop.conf.Configuration conf,
                      RegionServerServices server,
                      LastSequenceId sequenceIdChecker,
                      WALFactory factory)

方法详细资料

run

public void run()

指定者:

run 在接口中 Runnable

stopTask

public void stopTask()

If the worker is doing a task i.e. splitting a log file then stop the task. It doesn't exit the worker thread.

start

public void start()

start the SplitLogWorker thread

stop

public void stop()

stop the SplitLogWorker thread

getTaskReadySeq

public int getTaskReadySeq()

Returns the number of tasks processed by coordination. This method is used by tests only