Glassfish example source code file (GMSAnnounceBeforeStopClusterCommand.java)

This example Glassfish source code file (GMSAnnounceBeforeStopClusterCommand.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Glassfish tags/keywords

actionreport, empty_list, empty_list, gmsadapter, gmsannouncesupplementalinfo, group_start, groupmanagementservice, inject, inject, linkedlist, list, list, log, logging, param, param, util

The Glassfish GMSAnnounceBeforeStopClusterCommand.java source code

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 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
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package org.glassfish.gms.admin;

import com.sun.logging.LogDomains;
import org.glassfish.gms.bootstrap.GMSAdapterService;
import org.glassfish.gms.bootstrap.GMSAdapter;
import com.sun.enterprise.config.serverbeans.*;
import com.sun.enterprise.ee.cms.core.GMSConstants;
import org.glassfish.api.ActionReport;
import org.glassfish.api.Param;
import org.glassfish.api.admin.*;
import org.jvnet.hk2.annotations.Inject;
import org.jvnet.hk2.annotations.Scoped;
import org.jvnet.hk2.annotations.Service;
import org.jvnet.hk2.component.Habitat;
import org.jvnet.hk2.component.PerLookup;

import java.util.*;

import com.sun.enterprise.config.serverbeans.Domain;
import com.sun.enterprise.ee.cms.core.GroupManagementService;

import java.util.LinkedList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;


/**
 * Informs the dynamic group-management-service of Shoal GMS that all members of the cluster are stopping.
 * The GMS Notification PlannedShutdownNotification will have a subeventype of GROUP_SHUTDOWN rather than
 * INSTANCE_SHUTDOWN.  GMS clients may take advantage of this information that the entire cluster is stopping
 * rather than a single instance.
 */
@Service(name = "_gms-announce-before-stop-cluster-command")
@Supplemental(value = "stop-cluster", on = Supplemental.Timing.Before, ifFailure = FailurePolicy.Warn)
@Scoped(PerLookup.class)
public class GMSAnnounceBeforeStopClusterCommand implements AdminCommand {

    private static final Logger logger = LogDomains.getLogger(
        GMSAnnounceBeforeStopClusterCommand.class, LogDomains.GMS_LOGGER);

    @Inject
    private ServerEnvironment env;
    @Param(optional = false, primary = true)
    private String clusterName;
    @Inject
    private Domain domain;
    @Param(optional = true, defaultValue = "false")
    private boolean verbose;
    @Inject
    private GMSAdapterService gmsAdapterService;

    private GroupManagementService gms = null;
    private boolean gmsStopCluster = false;
    private List<String> clusterMembers = EMPTY_LIST;
    private GMSAdapter gmsadapter = null;

    static final private List<String> EMPTY_LIST = new LinkedList();


    @Override
    public void execute(AdminCommandContext context) {
        ActionReport report = context.getActionReport();
        try {
            if (gmsAdapterService.isGmsEnabled()) {
                gmsadapter = gmsAdapterService.getGMSAdapterByName(clusterName);

                //  gmsadapter can be null if GMSEnabled=false for clusterName.
                if (gmsadapter != null) {
                    gms = gmsadapter.getModule();
                    if (gms != null) {
                        clusterMembers = getClusterMembers();

                        // no need to announce a zero instance cluster.
                        if (clusterMembers != null && clusterMembers.size() > 0) {

                            // one or more clustered instances for this cluster in domain.xml.
                            // now check if any clustered instance are already running.
                            // DAS is a SPECTATOR so it will not be in list of current core members.
                            // If one or more clustered instances is already running,  do not consider this a GROUP_STARTUP,
                            // but treat as a series of individual INSTANCE_STARTUP for instances that do get started.
                            // no gms calls needed if not a GROUP_STARTUP.
                            List<String> startedGMSMembers = gms.getGroupHandle().getCurrentCoreMembers();
                            if (startedGMSMembers.size() > 0) {
                                try {
                                    // must be called on DAS only.
                                    gms.announceGroupShutdown(clusterName, GMSConstants.shutdownState.INITIATED);
                                    gmsStopCluster = true;
                                } catch (Throwable t) {

                                    // ensure gms group startup announcement does not interfere with starting cluster.
                                    // any exception here should not interfer with starting cluster.
                                    logger.log(Level.WARNING,
                                        "cluster.stop.exception",
                                        t.getLocalizedMessage());
                                }
                            } // else from GMS perspective treat remaining instances getting started as INSTANCE_START, not GROUP_START.
                            // nothing gms specific to do for this case.
                        }
                    }
                }
            }
        } finally {
            if (gms != null) {
                GMSAnnounceSupplementalInfo result = new GMSAnnounceSupplementalInfo(clusterMembers, gmsStopCluster, gmsadapter);
                report.setResultType(GMSAnnounceSupplementalInfo.class,  result);
            }
        }
    }

    private List<String> getClusterMembers() {
        List<String> clusterMembers = EMPTY_LIST;
        com.sun.enterprise.config.serverbeans.Cluster cluster = domain.getClusterNamed(clusterName);
        List<Server> targetServers = null;
        if (cluster != null) {
            // Get the list of servers in the cluster.
            targetServers = domain.getServersInTarget(clusterName);
            if (targetServers != null) {
                clusterMembers = new ArrayList<String>(targetServers.size());
                for (Server server : targetServers) {
                    clusterMembers.add(server.getName());
                }
            }
        }
        return clusterMembers;
    }
}