org.adroitlogic.x.clustering.failover

Class FailoverClusterPaths

java.lang.Object

org.adroitlogic.x.clustering.failover.FailoverClusterPaths

Direct Known Subclasses:

GroupFailoverClusterPaths, NodeWiseFailoverClusterPaths

public abstract class FailoverClusterPaths
extends Object

An extension to the ClusterPaths used by the cluster manager. The intention of this class is to add failover related cluster paths to the ZooKeeper ensemble.

Since:

17.01

Author:

Imesha Sudasingha

Field Summary

Fields

Modifier and Type	Field and Description
protected ClusterPaths	clusterPaths Cluster paths used by the cluster manager
protected String	failoverZNodePath The ZNode path where all the failover related ZNodes will be created under.
protected String	failoverZNodeRoot
protected String	strategiesZNodePath The ZNode path where each of the failover strategies will be implemented under.
protected String	strategiesZNodeRoot
protected String	strategyZNodePath The base path of the ZNodes related to this strategy.
protected String	strategyZNodeRoot

Constructor Summary

Constructors

Constructor and Description
FailoverClusterPaths()

Method Summary

Modifier and Type	Method and Description
void	clearAll(org.apache.curator.framework.CuratorFramework client) Clear the ZNodes (specially the ephemeral nodes) responsible for failover handling of this node.
protected abstract void	clearAllClusterPaths(org.apache.curator.framework.CuratorFramework client) Clears all cluster paths
void	createAll(org.apache.curator.framework.CuratorFramework client) Creates all the cluster paths required for the failover processing.
protected abstract void	createAllClusterPaths(org.apache.curator.framework.CuratorFramework client) Creates all cluster paths
abstract void	createAllEphemeralNodes(org.apache.curator.framework.CuratorFramework client) This method will be called whenever a connection reconnection happens.
abstract String	getClusterLockZNodePathSuffix(String entityName) Get the path, on which a cluster lock to be taken whenever a distributed lock has to be acquired to start failover.
ClusterPaths	getClusterPaths()
String	getFailoverZNodePath()
String	getFailoverZNodeRoot()
String	getStrategiesZNodePath()
String	getStrategiesZNodeRoot()
abstract String	getStrategyName() Get the name of the strategy to which this cluster path pattern is binded to
String	getStrategyZNodePath()
String	getStrategyZNodeRoot()
void	initialize(ClusterPaths clusterPaths) Initializes the failover related cluster paths by generating the ZNode path names
protected abstract void	initializeClusterPaths() Initializes the cluster paths

Methods inherited from class java.lang.Object

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

Field Detail

clusterPaths

protected ClusterPaths clusterPaths

Cluster paths used by the cluster manager

failoverZNodePath

protected String failoverZNodePath

The ZNode path where all the failover related ZNodes will be created under. /${domain}/failover

failoverZNodeRoot

protected String failoverZNodeRoot

strategiesZNodePath

protected String strategiesZNodePath

The ZNode path where each of the failover strategies will be implemented under. /${domain}/failover/strategies

strategiesZNodeRoot

protected String strategiesZNodeRoot

strategyZNodePath

protected String strategyZNodePath

The base path of the ZNodes related to this strategy. /${domain}/failover/strategies/${STRATEGY_NAME}

strategyZNodeRoot

protected String strategyZNodeRoot

Constructor Detail

FailoverClusterPaths

public FailoverClusterPaths()

Method Detail

initialize

public void initialize(ClusterPaths clusterPaths)

Initializes the failover related cluster paths by generating the ZNode path names

Parameters:

clusterPaths - ClusterPaths instance of this node's cluster manager

createAll

public void createAll(org.apache.curator.framework.CuratorFramework client)

Creates all the cluster paths required for the failover processing. This will also call the createAllClusterPaths(CuratorFramework) to create all the ZNode paths required by the child classes

Parameters:

client - CuratorFramework instance

clearAll

public void clearAll(org.apache.curator.framework.CuratorFramework client)

Clear the ZNodes (specially the ephemeral nodes) responsible for failover handling of this node. This should not delete the persistent ZNodes which are being used by other nodes for failover.

Parameters:

client - CuratorFramework instance

initializeClusterPaths

protected abstract void initializeClusterPaths()

Initializes the cluster paths

See Also:

initialize(ClusterPaths)

createAllClusterPaths

protected abstract void createAllClusterPaths(org.apache.curator.framework.CuratorFramework client)

Creates all cluster paths

Parameters:

client - the curator framework to be used for creation

See Also:

createAll(CuratorFramework)

clearAllClusterPaths

protected abstract void clearAllClusterPaths(org.apache.curator.framework.CuratorFramework client)

Clears all cluster paths

Parameters:

client - the curator framework to be used for clearing

See Also:

clearAll(CuratorFramework)

createAllEphemeralNodes

public abstract void createAllEphemeralNodes(org.apache.curator.framework.CuratorFramework client)

This method will be called whenever a connection reconnection happens. That is, whenever the connection is lost, we cannot guarantee that the ephemeral nodes we created at the beginning still exists as wwe may have lost our session. In order to address that, this method is called whenever the ephemeral nodes has to be created

Parameters:

client - CuratorFramework instance

getClusterLockZNodePathSuffix

public abstract String getClusterLockZNodePathSuffix(String entityName)

Get the path, on which a cluster lock to be taken whenever a distributed lock has to be acquired to start failover.

Parameters:

entityName - the name of the node, group etc.

Returns:

cluster lock path

getStrategyName

public abstract String getStrategyName()

Get the name of the strategy to which this cluster path pattern is binded to

Returns:

strategy name

getClusterPaths

public ClusterPaths getClusterPaths()

getFailoverZNodePath

public String getFailoverZNodePath()

getFailoverZNodeRoot

public String getFailoverZNodeRoot()

getStrategiesZNodePath

public String getStrategiesZNodePath()

getStrategiesZNodeRoot

public String getStrategiesZNodeRoot()

getStrategyZNodePath

public String getStrategyZNodePath()

getStrategyZNodeRoot

public String getStrategyZNodeRoot()