org.adroitlogic.x.api.clustering

Interface XClusterManager

All Superinterfaces:

Initializable, Startable

All Known Implementing Classes:

CuratorClusterManager

public interface XClusterManager
extends Startable, Initializable

This is the interface for the cluster manager which is to be used by an UltraESB-X instance. A class which is implementing this interface will be providing distributed locks and distributed sequence numbers. Apart from that, the implementation is capable of providing the functionality of a distributed command framework.

Since:

17.01

Method Summary

Modifier and Type	Method and Description
void	archiveCommand(int commandVersion) Archives a given command.
XClusterLock	getClusterLock(String lockPath) Returns a distributed lock unique to the given path.
String	getCommandSpace() Name of the command space to which this cluster manager is listening to.
int	getCurrentCommandVersion() Get's the current command version, which is the version of the last executed(by the command processor) command.
String	getDomain()
Optional<Integer>	getNextSequenceNumber(String path) Generates a distributed sequence number which is the next in line of a distributed sequence.
String	getNodeName()
CommandView	getPublishedCommandView(int commandVersion) Get the command view of the command with the given command version
Map<Integer,CommandView>	getPublishedCommandViews(int from, int to) Gets the published commands between given two command versions (inclusive).
Status	getStatus() Get the cluster manager's current Status.
String	publishControlCommand(String command) This method is to be used over the REST API.
String	publishControlCommand(XControlCommand command) Publishes a command to the cluster.
String	republishControlCommand(int commandVersion) Republish a control command which was once published.
void	retryCommand(int commandVersion) Retries a given command.

Methods inherited from interface org.adroitlogic.x.api.dec.Startable

start, stop

Methods inherited from interface org.adroitlogic.x.api.dec.Initializable

destroy, init

Method Detail

getClusterLock

XClusterLock getClusterLock(String lockPath)

Returns a distributed lock unique to the given path. The returned XClusterLock can be used to acquire a lock which will guarantee a critical section between different instances of the cluster manager (project x/ultraESB)

Parameters:

lockPath - lock path

Returns:

XClusterLock

getNextSequenceNumber

Optional<Integer> getNextSequenceNumber(String path)

Generates a distributed sequence number which is the next in line of a distributed sequence. this will return an Optional as the result. Users have to check whether the value is available.

Parameters:

path - path to be used to generate the sequence number

Returns:

next sequence number as an optional

publishControlCommand

String publishControlCommand(XControlCommand command)

Publishes a command to the cluster. An XControlCommand instance should be provided as the command. The command will be marshaled and sent to the zookeeper for publishing the command.

Parameters:

command - the command to be published

Returns:

the path of the newly created command ZNode | null if failed

publishControlCommand

String publishControlCommand(String command)

This method is to be used over the REST API. The command will be received as an marshaled command.

Parameters:

command - Marshaled XControlCommand

Returns:

the path of the newly created command ZNode | null if failed

See Also:

publishControlCommand(XControlCommand)

republishControlCommand

String republishControlCommand(int commandVersion)

Republish a control command which was once published. The command to be republished will be identified through the version number of the command.

Parameters:

commandVersion - Version of the command to be republished

Returns:

Name of the published command's ZNode | null

archiveCommand

void archiveCommand(int commandVersion)

Archives a given command. The command is identified by its version number which is appended to the ZNode name when a sequential node is being created

Parameters:

commandVersion - sequence number of the command which is to be archived

retryCommand

void retryCommand(int commandVersion)

Retries a given command. Command is obtained by the command version number

Parameters:

commandVersion - command version number to be retried

getCurrentCommandVersion

int getCurrentCommandVersion()

Get's the current command version, which is the version of the last executed(by the command processor) command.

Returns:

current command version

getPublishedCommandViews

Map<Integer,CommandView> getPublishedCommandViews(int from,
                                                  int to)

Gets the published commands between given two command versions (inclusive).

Parameters:

from - starting version from which the commands to be fetched

to - ending version up to which commands has to be fetched

Returns:

A map of published commands between those two versions with version number as the key and and the published command as the value.

getPublishedCommandView

CommandView getPublishedCommandView(int commandVersion)
                             throws Exception

Get the command view of the command with the given command version

Parameters:

commandVersion - command version

Returns:

command view

Throws:

Exception - if unable to fetch the command

getStatus

Status getStatus()

Get the cluster manager's current Status.

Returns:

state of the cluster manager

getCommandSpace

String getCommandSpace()

Name of the command space to which this cluster manager is listening to. The nodes in the same command space will receive the same cluster commands

Returns:

command space name

getNodeName

String getNodeName()

getDomain

String getDomain()