Simple Apache ZooKeeper test

output.log

Waiting to connect
WatchedEvent state:SyncConnected type:None path:null
Written 50

..snip snip...

Written 850
Written 900
Written 950
Written 1000
Wrote 1000 in 3854(ms)
Retrieved 1000 in 15(ms)
Children: (1000)
     msg0000000788
     msg0000000789

..snip snip...

     msg0000000357
     msg0000000358
Retrieving data...
     /all-msg/mbox-1A/msg0000000788 {This is a short msg. Hello #789. Blah blah.}
     /all-msg/mbox-1A/msg0000000789 {This is a short msg. Hello #790. Blah blah.}
     /all-msg/mbox-1A/msg0000000784 {This is a short msg. Hello #785. Blah blah.}

..snip snip...

     /all-msg/mbox-1A/msg0000000356 {This is a short msg. Hello #357. Blah blah.}
     /all-msg/mbox-1A/msg0000000357 {This is a short msg. Hello #358. Blah blah.}
     /all-msg/mbox-1A/msg0000000358 {This is a short msg. Hello #359. Blah blah.}
Retrieved data for 1000 children in 1119(ms)

SimpleZkTest.java

import org.apache.zookeeper.*;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.data.Stat;

import java.util.List;
import java.util.concurrent.atomic.AtomicReference;

/*
* Author: Ashwin Jayaprakash / Date: Jul 4, 2010 / Time: 6:35:45 PM / Contact: http://www.ashwinjayaprakash.com
*/
public class SimpleZkTest {
    public static void main(String[] args) throws Exception {
        final AtomicReference<KeeperState> stateRef = new AtomicReference<KeeperState>();

        ZooKeeper zk = new ZooKeeper("localhost", 2181, new Watcher() {
            public void process(WatchedEvent watchedEvent) {
                System.out.println(watchedEvent);

                stateRef.set(watchedEvent.getState());
            }
        });

        //-----------------

        //Error handling here is not exactly the recommended way.

        try {
            KeeperState state = null;

            while ((state = stateRef.get()) == null) {
                System.out.println("Waiting to connect");
                Thread.sleep(50);
            }
            if (state != KeeperState.SyncConnected) {
                throw new Exception("Oops! " + state);
            }

            //-----------------

            //Create root folder.

            String root = "/all-msg";
            Stat stat = zk.exists(root, false);
            if (stat == null) {
                zk.create(root, new byte[]{}, Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
            }

            //-----------------

            //Create another nested folder for this test.

            String mbox1A = root + "/mbox-1A";
            stat = zk.exists(mbox1A, false);
            if (stat == null) {
                zk.create(mbox1A, new byte[]{}, Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
            }

            //-----------------

            //Write a few short messages under that folder.

            String msgMbox1A = mbox1A + "/msg";

            long start = System.currentTimeMillis();
            int i = 1;
            for (; i <= 1000; i++) {
                String msg = "This is a short msg. Hello #" + i + ". Blah blah.";

                zk.create(msgMbox1A, msg.getBytes(),
                        Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT_SEQUENTIAL);

                if (i % 50 == 0) {
                    System.out.println("Written " + i);
                }
            }
            long end = System.currentTimeMillis();

            System.out.println("Wrote " + (i - 1) + " in " + (end - start) + "(ms)");

            //-----------------

            //Just get the headers or msg names.

            start = System.currentTimeMillis();
            List<String> msgNames = zk.getChildren(mbox1A, false);
            end = System.currentTimeMillis();
            System.out.println("Retrieved " + msgNames.size() + " in " + (end - start) + "(ms)");

            System.out.println("Children: (" + msgNames.size() + ")");
            for (String child : msgNames) {
                System.out.println("     " + child);
            }

            //-----------------

            //Now get the msgs.

            start = System.currentTimeMillis();

            System.out.println("Retrieving data...");
            for (String msgName : msgNames) {
                String fqn = mbox1A + "/" + msgName;

                byte[] bytes = zk.getData(fqn, false, null);

                String msg = new String(bytes);
                System.out.println("     " + fqn + " {" + msg + "}");
            }
            end = System.currentTimeMillis();
            System.out.println(
                    "Retrieved data for " + msgNames.size() + " children in "
                            + (end - start) + "(ms)");
        }
        finally {
            zk.close();
        }
    }
}

zkServer.cmd

..snip snip...

set GC_PARAMS=-XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:CMSInitiatingOccupancyFraction=75 -XX:+DisableExplicitGC -XX:+PrintTenuringDistribution -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintReferenceGC

set HEAP=-Xms1g -Xmx1g -XX:NewSize=256m -XX:MaxNewSize=256m

echo on
java %GC_PARAMS% %HEAP% "-Dzookeeper.log.dir=%ZOO_LOG_DIR%" "-Dzookeeper.root.logger=%ZOO_LOG4J_PROP%" -cp "%CLASSPATH%" %ZOOMAIN% "%ZOOCFG%" %*

..snip snip...