com.bigdata.quorum.QuorumClient Maven / Gradle / Ivy
/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
[email protected]
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Jun 2, 2010
*/
package com.bigdata.quorum;
import java.rmi.Remote;
import java.util.UUID;
/**
* A non-remote interface for a client which monitors the state of a quorum.
* This interface adds the ability to receive notice of quorum state changes and
* resolve the {@link Remote} interface for the member services of the quorum.
*
* @see AbstractQuorum#start(QuorumClient)
*
* @author Bryan Thompson
* @version $Id$
*/
public interface QuorumClient extends QuorumListener,
ServiceLookup {
/**
* The fully qualified identifier of the logical service whose quorum state
* will be monitored (for zookeeper, this is the logicalServiceZPath). A
* highly available service is comprised of multiple physical services which
* are instances of the same logical service.
*
* Note: The method was renamed from getLogicalServiceId() to
* {@link #getLogicalServiceZPath()} to avoid confusion with the zookeeper
* integration which has both a logicalServiceId (just the last component of
* the zpath) and a logicalServiceZPath. The {@link Quorum} and
* {@link QuorumClient} interfaces only understand a single logical service
* identifier - this is what corresponds to the
* for the zookeeper integration.
*
* @see QuorumMember#getServiceId()
*/
String getLogicalServiceZPath();
/**
* Life cycle message sent when the client will begin to receive messages
* from the {@link Quorum}. At a minimum, the client should save a reference
* to the {@link Quorum}.
*
* @param quorum
* The quorum.
*
* @see AbstractQuorum#start(QuorumClient)
*/
void start(Quorum quorum);
/**
* Life cycle message send when the client will no longer receive messages
* from the {@link Quorum}.
*
* @see AbstractQuorum#terminate()
*/
void terminate();
/**
* The client has become disconnected from the quorum (for zookeeper this is
* only generated if the session has expired rather than if there is a
* transient disconnect that can be cured). This callback provides a hook to
* take any local actions that are required when the client can not longer
* rely on its role in the quorum state (if the client is disconnected from
* the quorum, then it is no longer part of the quorum, can not be a joined
* service, quorum member, etc).
*/
void disconnected();
/**
* The quorum that is being monitored.
*
* @throws QuorumException
* if the client is not running with the quorum.
*
* @see #start(Quorum)
*/
Quorum getQuorum();
/**
* Return the remote interface used to perform HA operations on a member of
* quorum.
*
* @param serviceId
* The {@link UUID} associated with the service.
*
* @return The remote interface for that quorum member.
*
* @throws IllegalArgumentException
* if the argument is null
* @throws QuorumException
* if there is no {@link Quorum} member with that
* serviceId.
*/
S getService(UUID serviceId);
/**
* Return the remote interface used to perform HA operations on the quorum
* leader.
*
* @param token
* The quorum token for which the request was made.
*
* @return The remote interface for the leader.
*
* @throws QuorumException
* if the quorum token is no longer valid.
*/
S getLeader(long token);
}