Package de.aristaflow.adept2.core.cluster

Interface ClusterService

All Superinterfaces:

ADEPT2Service

All Known Implementing Classes:

ClusterNode

public interface ClusterService
extends ADEPT2Service

This class allows for communication between different nodes of a cluster. The second way to exchange status information helps in case of problems. For instance a doubtful server may signalling that it has terminated and cannot access the database any more.
Note that the cluster service can only be reached remotely in case it is exported by the platform. That means, the platform has to be successfully bootstrapped.

Method Summary

Modifier and Type	Method	Description
SimpleClusterNodeInformation	doubtfulStatus(SessionToken session, String requestingNode, long lastRequesterUpdate, long lastServerUpdate, long serverRunningSince)	Gets information on the cluster node implementing this cluster service and signals this cluster node, that its status is doubtful.
SimpleClusterNodeInformation	getNodeInformation(SessionToken session)	Gets information on the cluster node implementing this cluster service.

Methods inherited from interface de.aristaflow.adept2.base.service.ADEPT2Service

getLocalUris, getRelease, getRuntimeRequiredServices, getServiceInstanceName, getStartupRequiredServices, getURIs, init, ping, preShutdown, shutdown, start

Method Detail

getNodeInformation

SimpleClusterNodeInformation getNodeInformation(SessionToken session)

Gets information on the cluster node implementing this cluster service.

Parameters:

session - The session which is used to check for access rights on this method.

Returns:

The simple information for this cluster node, that is name, address, status, last update time and running since. Status and last update time may differ from the values in the database, e. g. a node has changed its status but cannot access the database.

doubtfulStatus

SimpleClusterNodeInformation doubtfulStatus(SessionToken session,
                                            String requestingNode,
                                            long lastRequesterUpdate,
                                            long lastServerUpdate,
                                            long serverRunningSince)

Gets information on the cluster node implementing this cluster service and signals this cluster node, that its status is doubtful. This urges this cluster node to update the database shortly. In case of problems accessing the database, it may even signal its termination.

Parameters:

session - The session which is used to check for access rights on this method.

requestingNode - The name of the node notifying the doubtful status.

lastRequesterUpdate - The last time the requester has updated its status (which is the same as checking for the server status.

lastServerUpdate - The last time the server has updated its status in the database according to the requester. If this is older than the last update time of the server, the requester has not the latest status, thus the notified doubtful status is not valid (any more).

serverRunningSince - The time the server has switched to running in the database according to the requester. If this is older than the current running since time, the requester has not the latest status, thus the notified doubtful status is not valid (any more).

Returns:

The simple information for this cluster node, that is name, address, status, last update time and running since. Status and last update time may differ from the values in the database, e. g. a node has changed its status but cannot access the database.