Package org.apache.zookeeper.server

Class ContainerManager

java.lang.Object

org.apache.zookeeper.server.ContainerManager

public class ContainerManager
extends Object

Manages cleanup of container ZNodes. This class is meant to only be run from the leader. There's no harm in running from followers/observers but that will be extra work that's not needed. Once started, it periodically checks container nodes that have a cversion > 0 and have no children. A delete is attempted on the node. The result of the delete is unimportant. If the proposal fails or the container node is not empty there's no harm.

Constructor Summary

Constructors

Constructor	Description
ContainerManager(ZKDatabase zkDb, RequestProcessor requestProcessor, int checkIntervalMs, int maxPerMinute)
ContainerManager(ZKDatabase zkDb, RequestProcessor requestProcessor, int checkIntervalMs, int maxPerMinute, long maxNeverUsedIntervalMs)

Method Summary

Modifier and Type	Method	Description
void	checkContainers()	Manually check the containers.
protected Collection<String>	getCandidates()
protected long	getElapsed(DataNode node)
protected long	getMinIntervalMs()
protected void	postDeleteRequest(Request request)
void	start()	start/restart the timer the runs the check.
void	stop()	stop the timer if necessary.

Methods inherited from class java.lang.Object

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

Constructor Detail

ContainerManager

public ContainerManager(ZKDatabase zkDb,
                        RequestProcessor requestProcessor,
                        int checkIntervalMs,
                        int maxPerMinute)

Parameters:

zkDb - the ZK database

requestProcessor - request processer - used to inject delete container requests

checkIntervalMs - how often to check containers in milliseconds

maxPerMinute - the max containers to delete per second - avoids herding of container deletions

ContainerManager

public ContainerManager(ZKDatabase zkDb,
                        RequestProcessor requestProcessor,
                        int checkIntervalMs,
                        int maxPerMinute,
                        long maxNeverUsedIntervalMs)

Parameters:

zkDb - the ZK database

requestProcessor - request processer - used to inject delete container requests

checkIntervalMs - how often to check containers in milliseconds

maxPerMinute - the max containers to delete per second - avoids herding of container deletions

maxNeverUsedIntervalMs - the max time in milliseconds that a container that has never had any children is retained

Method Detail

start

public void start()

start/restart the timer the runs the check. Can safely be called multiple times.

stop

public void stop()

stop the timer if necessary. Can safely be called multiple times.

checkContainers

public void checkContainers()
                     throws InterruptedException

Manually check the containers. Not normally used directly

Throws:

InterruptedException

postDeleteRequest

protected void postDeleteRequest(Request request)
                          throws RequestProcessor.RequestProcessorException

Throws:

RequestProcessor.RequestProcessorException

getMinIntervalMs

protected long getMinIntervalMs()

getCandidates

protected Collection<String> getCandidates()

getElapsed

protected long getElapsed(DataNode node)