org.apache.cassandra.gms

Interface IEndpointStateChangeSubscriber

All Known Implementing Classes:

ActiveRepairService, LoadBroadcaster, ReconnectableSnitchHelper, RepairSession, StorageService, StreamSession

public interface IEndpointStateChangeSubscriber

This is called by an instance of the IEndpointStateChangePublisher to notify interested parties about changes in the the state associated with any endpoint. For instance if node A figures there is a changes in state for an endpoint B it notifies all interested parties of this change. It is upto to the registered instance to decide what he does with this change. Not all modules maybe interested in all state changes.

Method Summary

Modifier and Type	Method and Description
void	beforeChange(java.net.InetAddress endpoint, EndpointState currentState, ApplicationState newStateKey, VersionedValue newValue)
void	onAlive(java.net.InetAddress endpoint, EndpointState state)
void	onChange(java.net.InetAddress endpoint, ApplicationState state, VersionedValue value)
void	onDead(java.net.InetAddress endpoint, EndpointState state)
void	onJoin(java.net.InetAddress endpoint, EndpointState epState) Use to inform interested parties about the change in the state for specified endpoint
void	onRemove(java.net.InetAddress endpoint)
void	onRestart(java.net.InetAddress endpoint, EndpointState state) Called whenever a node is restarted.

Method Detail

onJoin

void onJoin(java.net.InetAddress endpoint,
            EndpointState epState)

Use to inform interested parties about the change in the state for specified endpoint

Parameters:

endpoint - endpoint for which the state change occurred.

epState - state that actually changed for the above endpoint.

beforeChange

void beforeChange(java.net.InetAddress endpoint,
                  EndpointState currentState,
                  ApplicationState newStateKey,
                  VersionedValue newValue)

onChange

void onChange(java.net.InetAddress endpoint,
              ApplicationState state,
              VersionedValue value)

onAlive

void onAlive(java.net.InetAddress endpoint,
             EndpointState state)

onDead

void onDead(java.net.InetAddress endpoint,
            EndpointState state)

onRemove

void onRemove(java.net.InetAddress endpoint)

onRestart

void onRestart(java.net.InetAddress endpoint,
               EndpointState state)

Called whenever a node is restarted. Note that there is no guarantee when that happens that the node was previously marked down. It will have only if state.isAlive() == false as state is from before the restarted node is marked up.