org.wso2.broker.coordination.rdbms

Class RdbmsCoordinationDaoImpl

java.lang.Object

org.wso2.broker.coordination.rdbms.RdbmsCoordinationDaoImpl

public class RdbmsCoordinationDaoImpl
extends Object

Abstraction of the underlying database used with RDBMS coordination.

Constructor Summary

Constructors

Constructor and Description
RdbmsCoordinationDaoImpl(DataSource datasource) Default constructor which uses the provided datasource.

Method Summary

Modifier and Type	Method and Description
boolean	checkIfCoordinatorValid(int age) Check if the coordinator is invalid using the heart beat value.
boolean	checkIsCoordinator(String nodeId) Check if the given node is the coordinator.
void	clearMembershipEvents(String nodeID) Method to remove all membership events for a particular node.
protected void	close(Connection connection, String task) Closes the provided connection, on failure logs the error.
protected void	close(PreparedStatement preparedStatement, String task) Close the prepared statement resource.
protected void	close(ResultSet resultSet, String task) Close the result set resource.
boolean	createCoordinatorEntry(String nodeId) Method to create coordinator entry (i.e - make this node the coordinator).
void	createNodeHeartbeatEntry(String nodeId) Method to create the node heartbeat entry.
List<NodeHeartbeatData>	getAllHeartBeatData() Get node heart beat status for all the existing nodes.
protected Connection	getConnection() Create a connection using a thread pooled data source object and return the connection.
String	getCoordinatorNodeId() Retrieve the current coordinator's node ID.
void	markNodeAsNotNew(String nodeId) Method to indicate that the coordinator detected a node addition.
List<MembershipEvent>	readMembershipEvents(String nodeID) Method to read cluster membership change events for a nodeID.
void	removeCoordinator() Remove current coordinator entry from database.
void	removeNodeHeartbeat(String nodeId) Remove heartbeat entry for the given node.
protected void	rollback(Connection connection, String task) On database update failure try to rollback.
void	storeMembershipEvent(List<String> clusterNodes, int membershipEventType, String changedMember) Method to store cluster membership events.
boolean	updateCoordinatorHeartbeat(String nodeId) Update coordinator heartbeat value to current time.
boolean	updateNodeHeartbeat(String nodeId) Method to update the node heartbeat value to the current time.

Methods inherited from class java.lang.Object

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

Constructor Detail

RdbmsCoordinationDaoImpl

public RdbmsCoordinationDaoImpl(DataSource datasource)

Default constructor which uses the provided datasource.

Parameters:

datasource - the datasource to use

Method Detail

clearMembershipEvents

public void clearMembershipEvents(String nodeID)
                           throws CoordinationException

Method to remove all membership events for a particular node.

Throws:

CoordinationException

removeNodeHeartbeat

public void removeNodeHeartbeat(String nodeId)
                         throws CoordinationException

Remove heartbeat entry for the given node. This is normally done when the coordinator detects that the node has left.

Parameters:

nodeId - local node ID

Throws:

CoordinationException - if an error occurs while removing the node heartbeat entry (mostly due to a DB error)

getAllHeartBeatData

public List<NodeHeartbeatData> getAllHeartBeatData()
                                            throws CoordinationException

Get node heart beat status for all the existing nodes.

Returns:

list of node heartbeat data

Throws:

CoordinationException - if an error is detected while calling the store (mostly due to a DB error)

getCoordinatorNodeId

public String getCoordinatorNodeId()
                            throws CoordinationException

Retrieve the current coordinator's node ID.

Returns:

node ID of the current coordinator

Throws:

CoordinationException - if an error is detected while retrieving the node ID of the coordinator

removeCoordinator

public void removeCoordinator()
                       throws CoordinationException

Remove current coordinator entry from database.

Throws:

CoordinationException - if an error is detected while removing the coordinator entry.

checkIfCoordinatorValid

public boolean checkIfCoordinatorValid(int age)
                                throws CoordinationException

Check if the coordinator is invalid using the heart beat value.

Parameters:

age - maximum relative age with respect to the current time in milliseconds.

Returns:

true if timed out, false otherwise

Throws:

CoordinationException - if an error occurs checking if the coordinator is valid.

updateNodeHeartbeat

public boolean updateNodeHeartbeat(String nodeId)
                            throws CoordinationException

Method to update the node heartbeat value to the current time.

Parameters:

nodeId - local node ID

Returns:

true if the update is successful, false otherwise

Throws:

CoordinationException - if an error is detected while updating the node heartbeat.

createNodeHeartbeatEntry

public void createNodeHeartbeatEntry(String nodeId)
                              throws CoordinationException

Method to create the node heartbeat entry.

Parameters:

nodeId - local node ID

Throws:

CoordinationException - if an error is detected while creating the node heartbeat entry.

updateCoordinatorHeartbeat

public boolean updateCoordinatorHeartbeat(String nodeId)
                                   throws CoordinationException

Update coordinator heartbeat value to current time.

Parameters:

nodeId - local node ID

Returns:

true if the update is successful, false otherwise

Throws:

CoordinationException - if an error is detected while updating the coordinator heartbeat.

markNodeAsNotNew

public void markNodeAsNotNew(String nodeId)
                      throws CoordinationException

Method to indicate that the coordinator detected a node addition.

Parameters:

nodeId - local node ID

Throws:

CoordinationException - if an error is detected while marking the node as not new.

createCoordinatorEntry

public boolean createCoordinatorEntry(String nodeId)
                               throws CoordinationException

Method to create coordinator entry (i.e - make this node the coordinator).

Parameters:

nodeId - local node ID

Returns:

true if creation is successful, false otherwise

Throws:

CoordinationException - if an error is detected while creating the coordinator entry

checkIsCoordinator

public boolean checkIsCoordinator(String nodeId)
                           throws CoordinationException

Check if the given node is the coordinator.

Parameters:

nodeId - local node ID

Returns:

true if the given node is the coordinator, false otherwise

Throws:

CoordinationException - if an error is detected while checking if coordinator

storeMembershipEvent

public void storeMembershipEvent(List<String> clusterNodes,
                                 int membershipEventType,
                                 String changedMember)
                          throws CoordinationException

Method to store cluster membership events.

Parameters:

clusterNodes - nodes by which the event is destined to be read

membershipEventType - the membership change type

changedMember - member for which the event was triggered

Throws:

CoordinationException - if an error is detected while storing membership events

readMembershipEvents

public List<MembershipEvent> readMembershipEvents(String nodeID)
                                           throws CoordinationException

Method to read cluster membership change events for a nodeID.

Parameters:

nodeID - local node ID used to read events for current node

Returns:

list of membership events

Throws:

CoordinationException - if an error is detected while retrieving the membership events

getConnection

protected Connection getConnection()
                            throws SQLException

Create a connection using a thread pooled data source object and return the connection.

Returns:

a connection to the datasource specified

Throws:

SQLException - if an error occurs with database access

close

protected void close(ResultSet resultSet,
                     String task)

Close the result set resource.

Parameters:

resultSet - the ResultSet

task - the task that was done by the closed result set

close

protected void close(PreparedStatement preparedStatement,
                     String task)

Close the prepared statement resource.

Parameters:

preparedStatement - the PreparedStatement

task - the task that was done by the closed prepared statement

close

protected void close(Connection connection,
                     String task)

Closes the provided connection, on failure logs the error.

Parameters:

connection - the Connection

task - the task that was done before closing

rollback

protected void rollback(Connection connection,
                        String task)

On database update failure try to rollback.

Parameters:

connection - the database connection

task - the task that was being done