VoldemortStatusPage.java Source code

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Here is the source code for VoldemortStatusPage.java

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/*
 * Developed by Srikanth P Shreenivas (srikanthps (at) yahoo (dot) com)
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Properties;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;
import org.mortbay.jetty.Server;
import org.mortbay.jetty.handler.AbstractHandler;

import voldemort.client.protocol.admin.AdminClient;
import voldemort.client.protocol.admin.AdminClientConfig;
import voldemort.cluster.Cluster;
import voldemort.cluster.Node;
import voldemort.store.metadata.MetadataStore.VoldemortState;

/**
 * @author Srikanth Shreenivas (http://www.srikanthps.com/)
 * License: MIT
 */
public class VoldemortStatusPage {

    Logger logger = Logger.getLogger(VoldemortStatusPage.class);

    public static void main(String[] args) throws Exception {

        if (args.length < 2) {
            System.out.println(
                    "Usage: java -cp .:/path/to/voldemort-installation/lib/* VoldemortStatusPage <http-port-number> <cluster-details>.properties");
            System.out
                    .println(" Properties file should contain list of bootstrap URLs that needs to be monitored.");
            System.out.println(" Example enries:");
            System.out.println(" cluster.1 = tcp://1.2.3.4:7001/");
            System.out.println(" cluster.2 = tcp://1.2.3.5:7001/");
            System.out.println(" cluster.3 = tcp://1.2.3.6:7001/");
            return;
        }

        Properties p = lookupProperties(args[1]);
        startJettyServer(Integer.valueOf(args[0]), p);
    }

    private static void startJettyServer(Integer portNumber, Properties p) throws Exception, InterruptedException {
        Server server = new Server(portNumber);
        server.setHandler(new StatusHandler(p));
        server.start();
        server.join();
    }

    private static Properties lookupProperties(String fileName) throws IOException, FileNotFoundException {
        Properties p = new Properties();
        File propertyFile = new File(fileName);
        FileInputStream is = null;
        is = new FileInputStream(propertyFile);
        p.load(is);
        is.close();
        return p;
    }

    private static String getNodeStatusAsHtml(AdminClient c, Node n) {
        try {
            VoldemortState state = c.getRemoteServerState(n.getId()).getValue();
            return inGreen(state.toString());
        } catch (Exception e) {
            return inRed("DOWN");
        }
    }

    private static String inGreen(String value) {
        return inColor("green", value);
    }

    private static String inRed(String value) {
        return inColor("red", value);
    }

    private static String inColor(String color, String value) {
        return "<span style=\"color:" + color + "\">" + value + "</span>";
    }

    public static class StatusHandler extends AbstractHandler {
        Logger logger = Logger.getLogger(StatusHandler.class);
        Properties clusters;

        /**
         * Provide clusters to manage in the following form in the properties file
         * cluster.1=<boot-strap-url-1>
         * cluster.2=<boot-strap-url-2>
         * cluster.3=<boot-strap-url-3>
         * ...
         */
        public StatusHandler(Properties clusters) {
            this.clusters = clusters;
        }

        @Override
        public void handle(String target, HttpServletRequest req, HttpServletResponse res, int dispatch)
                throws IOException, ServletException {

            res.setContentType("text/html;charset=utf-8");
            res.setStatus(HttpServletResponse.SC_OK);
            for (Object cluster : clusters.keySet()) {
                writeStatusForCluster(res, cluster.toString(), clusters.getProperty(cluster.toString()));
            }

            res.getWriter().close();
            res.setStatus(200);

        }

        private void writeStatusForCluster(HttpServletResponse res, String clusterName, String bootstrapUrl)
                throws IOException {

            res.getWriter().println("<h2>Voldemort Cluster '" + clusterName + "' Status </h2>");
            res.getWriter().println("<h4>(");

            try {
                String[] bootStrapUrls = bootstrapUrl.split(",");

                AdminClient reachableClient = null;
                for (String b : bootStrapUrls) {
                    if (StringUtils.isNotBlank(b)) {
                        try {
                            AdminClient c = new AdminClient(b, new AdminClientConfig());
                            res.getWriter().print(inGreen(b) + ",");
                            if (reachableClient == null) {
                                reachableClient = c;
                            }
                        } catch (Exception e) {
                            logger.error("Could not open admin client using: " + b, e);
                            res.getWriter().print(inRed(b) + ",");
                        }
                    }
                }
                res.getWriter().println(")</h4>");
                res.getWriter().println();

                for (String b : bootStrapUrls) {
                    if (StringUtils.isNotBlank(b)) {
                        try {
                            if (reachableClient != null) {
                                Cluster cluster = reachableClient.getAdminClientCluster();
                                for (Node n : cluster.getNodes()) {
                                    res.getWriter()
                                            .println("<div><span>" + n.getHost() + ":" + n.getSocketPort() + " : "
                                                    + "</span>" + getNodeStatusAsHtml(reachableClient, n)
                                                    + "</div>");
                                }
                                break;
                            }
                        } catch (Exception e) {
                            logger.error("Could not open admin client using: " + b, e);
                            res.getWriter().println(
                                    "<div><span>" + b + " : " + "</span>" + inRed("NOT REACHABLE") + "</div>");
                        }
                    }
                }
            } catch (Exception e) {
                logger.error(e);
            }
        }
    }
}