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Glassfish example source code file (ClusterCommandHelper.java)

This example Glassfish source code file (ClusterCommandHelper.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, arraylist, arraylist, commandrunnable, commandrunner, list, list, log, logging, parametermap, reportresult, server, string, string, stringbuilder, stringbuilder, threading, threads, util

The Glassfish ClusterCommandHelper.java source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 2010 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * 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
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
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 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
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 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package com.sun.enterprise.v3.admin.cluster;


import java.util.ArrayList;
import java.util.List;
import java.util.HashMap;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.TimeUnit;

import org.glassfish.api.admin.ParameterMap;
import org.glassfish.api.admin.CommandException;
import org.glassfish.api.admin.AdminCommandContext;
import org.glassfish.api.admin.CommandRunner;
import org.glassfish.api.admin.CommandRunner.CommandInvocation;
import org.glassfish.api.ActionReport;
import org.glassfish.api.ActionReport.ExitCode;
import com.sun.enterprise.admin.remote.RemoteAdminCommand;
import com.sun.enterprise.config.serverbeans.Server;
import com.sun.enterprise.config.serverbeans.Cluster;
import com.sun.enterprise.config.serverbeans.Domain;
import com.sun.enterprise.config.serverbeans.Config;
import com.sun.enterprise.v3.admin.adapter.AdminEndpointDecider;
import com.sun.grizzly.config.dom.ThreadPool;


/*
 * ClusterCommandHelper is a helper class that knows how to execute an
 * asadmin command in the DAS for each instance in a cluster. For example
 * it is used by start-cluster and stop-cluster to execute start-instance
 * or stop-instance for each instance in a cluster. Note this is not the
 * same as cluster replication where general commands are executed on
 * each instances of a cluster.
 *
 * @author Joe Di Pol
 */
class ClusterCommandHelper {

    private static final String NL = System.getProperty("line.separator");

    private Domain domain;

    private CommandRunner runner;

    /**
     * Construct a ClusterCommandHelper
     *
     * @param domain The Domain we are running in
     * @param runner A CommandRunner to use for running commands
     */
    ClusterCommandHelper(Domain domain, CommandRunner runner) {
        this.domain = domain;
        this.runner = runner;
    }

    /**
     * Loop through all instances in a cluster and execute a command for
     * each one.
     *
     * @param command       The string of the command to run. The instance
     *                      name will be used as the operand for the command.
     * @param map           A map of parameters to use for the command. May be
     *                      null if no parameters. When the command is
     *                      executed for a server instance, the instance name
     *                      is set as the DEFAULT parameter (operand)
     * @param clusterName   The name of the cluster containing the instances
     *                      to run the command against.
     * @param context       The AdminCommandContext to use when executing the
     *                      command.
     * @param verbose       true for more verbose output
     * @return              An ActionReport containing the results
     * @throws CommandException
     */
    ActionReport runCommand(
            String  command,
            ParameterMap map,
            String  clusterName,
            AdminCommandContext context,
            boolean verbose) throws CommandException {

        // When we started
        final long startTime = System.currentTimeMillis();

        Logger logger = context.getLogger();
        ActionReport report = context.getActionReport();

        // Get the cluster specified by clusterName
        Cluster cluster = domain.getClusterNamed(clusterName);
        if (cluster == null) {
            String msg = Strings.get("cluster.command.unknownCluster",
                    clusterName);
            throw new CommandException(msg);
        }

        // Get the list of servers in the cluster.
        List<Server> targetServers = domain.getServersInTarget(clusterName);

        // If the cluster is empty, say so
        if (targetServers == null || targetServers.isEmpty()) {
            report.setActionExitCode(ExitCode.SUCCESS);
            report.setMessage(Strings.get("cluster.command.noInstances",
                                            clusterName));
            return report;
        }
        int nInstances = targetServers.size();

        // We will save the name of the instances that worked and did
        // not work so we can summarize our results.
        StringBuilder failedServerNames = new StringBuilder();
        StringBuilder succeededServerNames = new StringBuilder();
        List<String> waitingForServerNames = new ArrayList();
        String msg;
        ReportResult reportResult = new ReportResult();
        boolean failureOccurred = false;

        // Save command output to return in ActionReport
        StringBuilder output = new StringBuilder();


        // Optimize the oder of server instances to avoid clumping on nodes
        logger.fine(String.format("Original instance list %s",
                serverListToString(targetServers)));
        targetServers = optimizeServerListOrder(targetServers);

        // Holds responses from the threads running the command
        ArrayBlockingQueue<CommandRunnable> responseQueue = 
                    new ArrayBlockingQueue<CommandRunnable>(nInstances);

        // Make the thread pool use the smaller of the number of instances
        // or half the admin thread pool size.
        int adminThreadPoolSize = getAdminThreadPoolSize(logger);
        int threadPoolSize = Math.min(nInstances, adminThreadPoolSize / 2);
        if (threadPoolSize < 1)
            threadPoolSize = 1;

        ExecutorService threadPool = Executors.newFixedThreadPool(threadPoolSize);

        if (map == null) {
            map = new ParameterMap();
        }

        logger.info(String.format(
            "Executing %s on %d instances using a thread pool of size %d: %s",
            command, nInstances, threadPoolSize,
            serverListToString(targetServers)));

        // Loop through instance names, construct the command for each
        // instance name, and hand it off to the threadpool.
        for (Server server : targetServers) {
            String iname = server.getName();
            waitingForServerNames.add(iname);

            ParameterMap instanceParameterMap = new ParameterMap(map);
            // Set the instance name as the operand for the commnd
            instanceParameterMap.set("DEFAULT", iname);

            ActionReport instanceReport = runner.getActionReport("plain");
            instanceReport.setActionExitCode(ExitCode.SUCCESS);
            CommandInvocation invocation = runner.getCommandInvocation(
                        command, instanceReport);
            invocation.parameters(instanceParameterMap);

            msg = command + " " + iname;
            logger.info(msg);
            if (verbose) {
                output.append(msg).append(NL);
            }

            // Wrap the command invocation in a runnable and hand it off
            // to the thread pool
            CommandRunnable cmdRunnable = new CommandRunnable(invocation,
                    instanceReport, responseQueue);
            cmdRunnable.setName(iname);
            threadPool.execute(cmdRunnable);
        }

        logger.fine(String.format("%s commands queued, waiting for responses",
                command));

        // Make sure we don't wait longer than the admin read timeout. Set
        // our limit to be 3 seconds less.
        long adminTimeout = RemoteAdminCommand.getReadTimeout() - 3000;
        if (adminTimeout <= 0) {
            // This should never be the case
            adminTimeout = 57 * 1000;
        }
        logger.fine(String.format("Initial cluster command timeout: %d ms",
                adminTimeout));

        // Now go get results from the response queue.
        for (int n = 0; n < nInstances; n++) {
            long timeLeft = adminTimeout - (System.currentTimeMillis() - startTime);
            if (timeLeft < 0) {
                timeLeft = 0;
            }
            CommandRunnable cmdRunnable = null;
            try {
                //cmdRunnable = responseQueue.take();
                cmdRunnable = responseQueue.poll(timeLeft, TimeUnit.MILLISECONDS);
            } catch (InterruptedException e) {
                // This thread has been interrupted. Abort
                threadPool.shutdownNow();
                msg = Strings.get("cluster.command.interrupted", clusterName,
                        Integer.toString(n), Integer.toString(nInstances),
                        command);
                logger.warning(msg);
                output.append(msg).append(NL);
                failureOccurred = true;
                // Re-establish interrupted state on thread
                Thread.currentThread().interrupt();
                break;
            }

            if (cmdRunnable == null) {
                // We've timed out.
                break;
            }
            String iname = cmdRunnable.getName();
            waitingForServerNames.remove(iname);
            ActionReport instanceReport = cmdRunnable.getActionReport();
            logger.fine(String.format("Instance %d of %d (%s) has responded with %s",
                    n+1, nInstances, iname, instanceReport.getActionExitCode()));
            if (instanceReport.getActionExitCode() != ExitCode.SUCCESS) {
                // Bummer, the command had an error. Log and save output
                failureOccurred = true;
                failedServerNames.append(iname).append(" ");
                reportResult.failedServerNames.add(iname);
                msg = iname + ": " + instanceReport.getMessage();
                logger.severe(msg);
                output.append(msg).append(NL);
            } else {
                // Command worked. Note that too.
                succeededServerNames.append(iname).append(" ");
                reportResult.succeededServerNames.add(iname);
            }
        }

        report.setActionExitCode(ExitCode.SUCCESS);
        
        if (failureOccurred) {
            report.setResultType(List.class, reportResult.failedServerNames);
        } else {
            report.setResultType(List.class, reportResult.succeededServerNames);
        }


        // Display summary of started servers if in verbose mode or we
        // had one or more failures.
        if (succeededServerNames.length() > 0 && (verbose || failureOccurred)) {
            output.append(NL + Strings.get("cluster.command.instancesSucceeded",
                    command, succeededServerNames));
        }

        if (failureOccurred) {
            // Display summary of failed servers if we have any
            output.append(NL + Strings.get("cluster.command.instancesFailed",
                    command, failedServerNames));
            if (succeededServerNames.length() > 0) {
                // At least one instance started. Warning.
                report.setActionExitCode(ExitCode.WARNING);
            } else {
                // No instance started. Failure
                report.setActionExitCode(ExitCode.FAILURE);
            }
        }

        // Check for server that did not respond
        if (!waitingForServerNames.isEmpty()) {
            msg = Strings.get("cluster.command.instancesTimedOut",
                    command, listToString(waitingForServerNames));
            logger.warning(msg);
            if (output.length() > 0) {
                output.append(NL);
            }
            output.append(msg);
            report.setActionExitCode(ExitCode.WARNING);
        }

        report.setMessage(output.toString());
        return report;
    }

    /**
     * Get the size of the admin threadpool
     */
    private int getAdminThreadPoolSize(Logger logger) {

        final int DEFAULT_POOL_SIZE = 5;

        // Get the DAS configuratoin
        Config config = domain.getConfigNamed("server-config");
        if (config == null)
            return DEFAULT_POOL_SIZE;

        AdminEndpointDecider aed = new AdminEndpointDecider(config, logger);
        return aed.getMaxThreadPoolSize();
    }

    /**
     * Optimize the order of the list of servers. Basically we
     * want the server list to be ordered such that we rotate over
     * the nodes. For example we want: n1, n2, n3, n1, n2, n3
     * not: n1, n1, n2, n2, n3, n3. This is to spread the load
     * of operations across nodes.
     *
     * @param original a list of servers
     * @return a list of servers with a more optimal order
     */
    List<Server> optimizeServerListOrder(List original) {

        // Don't bother with all this if it's just two instances
        if (original.size() < 3) {
            return original;
        }

        // There must be a more efficient way to do this, but this is what
        // we do. We first distribute all the server instances into a table
        // that is indexed by node name. Then we snake over that table to
        // create the final list.

        // Key is the node name, value is the list of servers on that node
        HashMap<String, List serverTable =
                new HashMap<String, List();

        // Distribute servers into serverTable
        int count = 0;
        for (Server server : original) {
            String nodeName = server.getNodeRef();

            List<Server> serverList = serverTable.get(nodeName);
            if (serverList == null) {
                serverList = new ArrayList<Server>();
                serverTable.put(nodeName, serverList);
            }
            serverList.add(server);
            count++;
        }

        // Now snake through server table moving server entries from the
        // table to the final optimized list.
        List<Server> optimized = new ArrayList(count);
        Set<String> nodes = serverTable.keySet();
        while (count > 0) {
            for (String nodeName : nodes) {
                List<Server> serverList = serverTable.get(nodeName);
                if (! serverList.isEmpty()) {
                    optimized.add(serverList.remove(0));
                    count--;
                }
            }
        }

        return optimized;
    }

    private static String serverListToString(List<Server> servers) {
        StringBuilder sb = new StringBuilder();
        for (Server s : servers) {
            sb.append(s.getNodeRef() + ":" + s.getName() + " ");
        }
        return sb.toString().trim();
    }

    private static String listToString(List<String> slist) {
        StringBuilder sb = new StringBuilder();
        for (String s : slist) {
            sb.append(s + " ");
        }
        return sb.toString().trim();
    }

    static public class ReportResult {
        final public List<String> succeededServerNames = new ArrayList();
        final public List<String> failedServerNames = new ArrayList();
    }
}

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