You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@zookeeper.apache.org by bu...@apache.org on 2015/09/03 07:08:31 UTC
svn commit: r964125 [48/48] - in /websites/staging/zookeeper/trunk/content:
./ doc/r3.5.1-alpha/ doc/r3.5.1-alpha/api/ doc/r3.5.1-alpha/api/org/
doc/r3.5.1-alpha/api/org/apache/ doc/r3.5.1-alpha/api/org/apache/zookeeper/
doc/r3.5.1-alpha/api/org/apache...
Added: websites/staging/zookeeper/trunk/content/doc/r3.5.1-alpha/zookeeperTutorial.html
==============================================================================
--- websites/staging/zookeeper/trunk/content/doc/r3.5.1-alpha/zookeeperTutorial.html (added)
+++ websites/staging/zookeeper/trunk/content/doc/r3.5.1-alpha/zookeeperTutorial.html Thu Sep 3 05:08:27 2015
@@ -0,0 +1,879 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html>
+<head>
+<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
+<meta content="Apache Forrest" name="Generator">
+<meta name="Forrest-version" content="0.9">
+<meta name="Forrest-skin-name" content="pelt">
+<title>Programming with ZooKeeper - A basic tutorial</title>
+<link type="text/css" href="skin/basic.css" rel="stylesheet">
+<link media="screen" type="text/css" href="skin/screen.css" rel="stylesheet">
+<link media="print" type="text/css" href="skin/print.css" rel="stylesheet">
+<link type="text/css" href="skin/profile.css" rel="stylesheet">
+<script src="skin/getBlank.js" language="javascript" type="text/javascript"></script><script src="skin/getMenu.js" language="javascript" type="text/javascript"></script><script src="skin/fontsize.js" language="javascript" type="text/javascript"></script>
+<link rel="shortcut icon" href="images/favicon.ico">
+</head>
+<body onload="init()">
+<script type="text/javascript">ndeSetTextSize();</script>
+<div id="top">
+<!--+
+ |breadtrail
+ +-->
+<div class="breadtrail">
+<a href="http://www.apache.org/">Apache</a> > <a href="http://zookeeper.apache.org/">ZooKeeper</a> > <a href="http://zookeeper.apache.org/">ZooKeeper</a><script src="skin/breadcrumbs.js" language="JavaScript" type="text/javascript"></script>
+</div>
+<!--+
+ |header
+ +-->
+<div class="header">
+<!--+
+ |start group logo
+ +-->
+<div class="grouplogo">
+<a href="http://hadoop.apache.org/"><img class="logoImage" alt="Hadoop" src="images/hadoop-logo.jpg" title="Apache Hadoop"></a>
+</div>
+<!--+
+ |end group logo
+ +-->
+<!--+
+ |start Project Logo
+ +-->
+<div class="projectlogo">
+<a href="http://zookeeper.apache.org/"><img class="logoImage" alt="ZooKeeper" src="images/zookeeper_small.gif" title="ZooKeeper: distributed coordination"></a>
+</div>
+<!--+
+ |end Project Logo
+ +-->
+<!--+
+ |start Search
+ +-->
+<div class="searchbox">
+<form action="http://www.google.com/search" method="get" class="roundtopsmall">
+<input value="zookeeper.apache.org" name="sitesearch" type="hidden"><input onFocus="getBlank (this, 'Search the site with google');" size="25" name="q" id="query" type="text" value="Search the site with google">
+ <input name="Search" value="Search" type="submit">
+</form>
+</div>
+<!--+
+ |end search
+ +-->
+<!--+
+ |start Tabs
+ +-->
+<ul id="tabs">
+<li>
+<a class="unselected" href="http://zookeeper.apache.org/">Project</a>
+</li>
+<li>
+<a class="unselected" href="https://cwiki.apache.org/confluence/display/ZOOKEEPER/">Wiki</a>
+</li>
+<li class="current">
+<a class="selected" href="index.html">ZooKeeper 3.5 Documentation</a>
+</li>
+</ul>
+<!--+
+ |end Tabs
+ +-->
+</div>
+</div>
+<div id="main">
+<div id="publishedStrip">
+<!--+
+ |start Subtabs
+ +-->
+<div id="level2tabs"></div>
+<!--+
+ |end Endtabs
+ +-->
+<script type="text/javascript"><!--
+document.write("Last Published: " + document.lastModified);
+// --></script>
+</div>
+<!--+
+ |breadtrail
+ +-->
+<div class="breadtrail">
+
+
+ </div>
+<!--+
+ |start Menu, mainarea
+ +-->
+<!--+
+ |start Menu
+ +-->
+<div id="menu">
+<div onclick="SwitchMenu('menu_1.1', 'skin/')" id="menu_1.1Title" class="menutitle">Overview</div>
+<div id="menu_1.1" class="menuitemgroup">
+<div class="menuitem">
+<a href="index.html">Welcome</a>
+</div>
+<div class="menuitem">
+<a href="zookeeperOver.html">Overview</a>
+</div>
+<div class="menuitem">
+<a href="zookeeperStarted.html">Getting Started</a>
+</div>
+<div class="menuitem">
+<a href="releasenotes.html">Release Notes</a>
+</div>
+</div>
+<div onclick="SwitchMenu('menu_selected_1.2', 'skin/')" id="menu_selected_1.2Title" class="menutitle" style="background-image: url('skin/images/chapter_open.gif');">Developer</div>
+<div id="menu_selected_1.2" class="selectedmenuitemgroup" style="display: block;">
+<div class="menuitem">
+<a href="api/index.html">API Docs</a>
+</div>
+<div class="menuitem">
+<a href="zookeeperProgrammers.html">Programmer's Guide</a>
+</div>
+<div class="menuitem">
+<a href="javaExample.html">Java Example</a>
+</div>
+<div class="menupage">
+<div class="menupagetitle">Barrier and Queue Tutorial</div>
+</div>
+<div class="menuitem">
+<a href="recipes.html">Recipes</a>
+</div>
+</div>
+<div onclick="SwitchMenu('menu_1.3', 'skin/')" id="menu_1.3Title" class="menutitle">Admin & Ops</div>
+<div id="menu_1.3" class="menuitemgroup">
+<div class="menuitem">
+<a href="zookeeperAdmin.html">Administrator's Guide</a>
+</div>
+<div class="menuitem">
+<a href="zookeeperQuotas.html">Quota Guide</a>
+</div>
+<div class="menuitem">
+<a href="zookeeperJMX.html">JMX</a>
+</div>
+<div class="menuitem">
+<a href="zookeeperObservers.html">Observers Guide</a>
+</div>
+</div>
+<div onclick="SwitchMenu('menu_1.4', 'skin/')" id="menu_1.4Title" class="menutitle">Contributor</div>
+<div id="menu_1.4" class="menuitemgroup">
+<div class="menuitem">
+<a href="zookeeperInternals.html">ZooKeeper Internals</a>
+</div>
+</div>
+<div onclick="SwitchMenu('menu_1.5', 'skin/')" id="menu_1.5Title" class="menutitle">Miscellaneous</div>
+<div id="menu_1.5" class="menuitemgroup">
+<div class="menuitem">
+<a href="https://cwiki.apache.org/confluence/display/ZOOKEEPER">Wiki</a>
+</div>
+<div class="menuitem">
+<a href="https://cwiki.apache.org/confluence/display/ZOOKEEPER/FAQ">FAQ</a>
+</div>
+<div class="menuitem">
+<a href="http://zookeeper.apache.org/mailing_lists.html">Mailing Lists</a>
+</div>
+</div>
+<div id="credit"></div>
+<div id="roundbottom">
+<img style="display: none" class="corner" height="15" width="15" alt="" src="skin/images/rc-b-l-15-1body-2menu-3menu.png"></div>
+<!--+
+ |alternative credits
+ +-->
+<div id="credit2"></div>
+</div>
+<!--+
+ |end Menu
+ +-->
+<!--+
+ |start content
+ +-->
+<div id="content">
+<div title="Portable Document Format" class="pdflink">
+<a class="dida" href="zookeeperTutorial.pdf"><img alt="PDF -icon" src="skin/images/pdfdoc.gif" class="skin"><br>
+ PDF</a>
+</div>
+<h1>Programming with ZooKeeper - A basic tutorial</h1>
+<div id="front-matter">
+<div id="minitoc-area">
+<ul class="minitoc">
+<li>
+<a href="#ch_Introduction">Introduction</a>
+</li>
+<li>
+<a href="#sc_barriers">Barriers</a>
+</li>
+<li>
+<a href="#sc_producerConsumerQueues">Producer-Consumer Queues</a>
+</li>
+<li>
+<a href="#sc_sourceListing">Complete Source Listing</a>
+</li>
+</ul>
+</div>
+</div>
+
+
+
+
+
+<a name="ch_Introduction"></a>
+<h2 class="h3">Introduction</h2>
+<div class="section">
+<p>In this tutorial, we show simple implementations of barriers and
+ producer-consumer queues using ZooKeeper. We call the respective classes Barrier and Queue.
+ These examples assume that you have at least one ZooKeeper server running.</p>
+<p>Both primitives use the following common excerpt of code:</p>
+<pre class="code">
+ static ZooKeeper zk = null;
+ static Integer mutex;
+
+ String root;
+
+ SyncPrimitive(String address) {
+ if(zk == null){
+ try {
+ System.out.println("Starting ZK:");
+ zk = new ZooKeeper(address, 3000, this);
+ mutex = new Integer(-1);
+ System.out.println("Finished starting ZK: " + zk);
+ } catch (IOException e) {
+ System.out.println(e.toString());
+ zk = null;
+ }
+ }
+ }
+
+ synchronized public void process(WatchedEvent event) {
+ synchronized (mutex) {
+ mutex.notify();
+ }
+ }
+</pre>
+<p>Both classes extend SyncPrimitive. In this way, we execute steps that are
+common to all primitives in the constructor of SyncPrimitive. To keep the examples
+simple, we create a ZooKeeper object the first time we instantiate either a barrier
+object or a queue object, and we declare a static variable that is a reference
+to this object. The subsequent instances of Barrier and Queue check whether a
+ZooKeeper object exists. Alternatively, we could have the application creating a
+ZooKeeper object and passing it to the constructor of Barrier and Queue.</p>
+<p>
+We use the process() method to process notifications triggered due to watches.
+In the following discussion, we present code that sets watches. A watch is internal
+structure that enables ZooKeeper to notify a client of a change to a node. For example,
+if a client is waiting for other clients to leave a barrier, then it can set a watch and
+wait for modifications to a particular node, which can indicate that it is the end of the wait.
+This point becomes clear once we go over the examples.
+</p>
+</div>
+
+
+<a name="sc_barriers"></a>
+<h2 class="h3">Barriers</h2>
+<div class="section">
+<p>
+ A barrier is a primitive that enables a group of processes to synchronize the
+ beginning and the end of a computation. The general idea of this implementation
+ is to have a barrier node that serves the purpose of being a parent for individual
+ process nodes. Suppose that we call the barrier node "/b1". Each process "p" then
+ creates a node "/b1/p". Once enough processes have created their corresponding
+ nodes, joined processes can start the computation.
+ </p>
+<p>In this example, each process instantiates a Barrier object, and its constructor takes as parameters:</p>
+<ul>
+<li>
+<p>the address of a ZooKeeper server (e.g., "zoo1.foo.com:2181")</p>
+</li>
+
+<li>
+<p>the path of the barrier node on ZooKeeper (e.g., "/b1")</p>
+</li>
+
+<li>
+<p>the size of the group of processes</p>
+</li>
+
+</ul>
+<p>The constructor of Barrier passes the address of the Zookeeper server to the
+constructor of the parent class. The parent class creates a ZooKeeper instance if
+one does not exist. The constructor of Barrier then creates a
+barrier node on ZooKeeper, which is the parent node of all process nodes, and
+we call root (<strong>Note:</strong> This is not the ZooKeeper root "/").</p>
+<pre class="code">
+ /**
+ * Barrier constructor
+ *
+ * @param address
+ * @param root
+ * @param size
+ */
+ Barrier(String address, String root, int size) {
+ super(address);
+ this.root = root;
+ this.size = size;
+
+ // Create barrier node
+ if (zk != null) {
+ try {
+ Stat s = zk.exists(root, false);
+ if (s == null) {
+ zk.create(root, new byte[0], Ids.OPEN_ACL_UNSAFE,
+ CreateMode.PERSISTENT);
+ }
+ } catch (KeeperException e) {
+ System.out
+ .println("Keeper exception when instantiating queue: "
+ + e.toString());
+ } catch (InterruptedException e) {
+ System.out.println("Interrupted exception");
+ }
+ }
+
+ // My node name
+ try {
+ name = new String(InetAddress.getLocalHost().getCanonicalHostName().toString());
+ } catch (UnknownHostException e) {
+ System.out.println(e.toString());
+ }
+
+ }
+</pre>
+<p>
+To enter the barrier, a process calls enter(). The process creates a node under
+the root to represent it, using its host name to form the node name. It then wait
+until enough processes have entered the barrier. A process does it by checking
+the number of children the root node has with "getChildren()", and waiting for
+notifications in the case it does not have enough. To receive a notification when
+there is a change to the root node, a process has to set a watch, and does it
+through the call to "getChildren()". In the code, we have that "getChildren()"
+has two parameters. The first one states the node to read from, and the second is
+a boolean flag that enables the process to set a watch. In the code the flag is true.
+</p>
+<pre class="code">
+ /**
+ * Join barrier
+ *
+ * @return
+ * @throws KeeperException
+ * @throws InterruptedException
+ */
+
+ boolean enter() throws KeeperException, InterruptedException{
+ zk.create(root + "/" + name, new byte[0], Ids.OPEN_ACL_UNSAFE,
+ CreateMode.EPHEMERAL_SEQUENTIAL);
+ while (true) {
+ synchronized (mutex) {
+ List<String> list = zk.getChildren(root, true);
+
+ if (list.size() < size) {
+ mutex.wait();
+ } else {
+ return true;
+ }
+ }
+ }
+ }
+</pre>
+<p>
+Note that enter() throws both KeeperException and InterruptedException, so it is
+the reponsability of the application to catch and handle such exceptions.</p>
+<p>
+Once the computation is finished, a process calls leave() to leave the barrier.
+First it deletes its corresponding node, and then it gets the children of the root
+node. If there is at least one child, then it waits for a notification (obs: note
+that the second parameter of the call to getChildren() is true, meaning that
+ZooKeeper has to set a watch on the the root node). Upon reception of a notification,
+it checks once more whether the root node has any child.</p>
+<pre class="code">
+ /**
+ * Wait until all reach barrier
+ *
+ * @return
+ * @throws KeeperException
+ * @throws InterruptedException
+ */
+
+ boolean leave() throws KeeperException, InterruptedException{
+ zk.delete(root + "/" + name, 0);
+ while (true) {
+ synchronized (mutex) {
+ List<String> list = zk.getChildren(root, true);
+ if (list.size() > 0) {
+ mutex.wait();
+ } else {
+ return true;
+ }
+ }
+ }
+ }
+ }
+</pre>
+</div>
+
+<a name="sc_producerConsumerQueues"></a>
+<h2 class="h3">Producer-Consumer Queues</h2>
+<div class="section">
+<p>
+A producer-consumer queue is a distributed data estructure thata group of processes
+use to generate and consume items. Producer processes create new elements and add
+them to the queue. Consumer processes remove elements from the list, and process them.
+In this implementation, the elements are simple integers. The queue is represented
+by a root node, and to add an element to the queue, a producer process creates a new node,
+a child of the root node.
+</p>
+<p>
+The following excerpt of code corresponds to the constructor of the object. As
+with Barrier objects, it first calls the constructor of the parent class, SyncPrimitive,
+that creates a ZooKeeper object if one doesn't exist. It then verifies if the root
+node of the queue exists, and creates if it doesn't.
+</p>
+<pre class="code">
+ /**
+ * Constructor of producer-consumer queue
+ *
+ * @param address
+ * @param name
+ */
+ Queue(String address, String name) {
+ super(address);
+ this.root = name;
+ // Create ZK node name
+ if (zk != null) {
+ try {
+ Stat s = zk.exists(root, false);
+ if (s == null) {
+ zk.create(root, new byte[0], Ids.OPEN_ACL_UNSAFE,
+ CreateMode.PERSISTENT);
+ }
+ } catch (KeeperException e) {
+ System.out
+ .println("Keeper exception when instantiating queue: "
+ + e.toString());
+ } catch (InterruptedException e) {
+ System.out.println("Interrupted exception");
+ }
+ }
+ }
+</pre>
+<p>
+A producer process calls "produce()" to add an element to the queue, and passes
+an integer as an argument. To add an element to the queue, the method creates a
+new node using "create()", and uses the SEQUENCE flag to instruct ZooKeeper to
+append the value of the sequencer counter associated to the root node. In this way,
+we impose a total order on the elements of the queue, thus guaranteeing that the
+oldest element of the queue is the next one consumed.
+</p>
+<pre class="code">
+ /**
+ * Add element to the queue.
+ *
+ * @param i
+ * @return
+ */
+
+ boolean produce(int i) throws KeeperException, InterruptedException{
+ ByteBuffer b = ByteBuffer.allocate(4);
+ byte[] value;
+
+ // Add child with value i
+ b.putInt(i);
+ value = b.array();
+ zk.create(root + "/element", value, Ids.OPEN_ACL_UNSAFE,
+ CreateMode.PERSISTENT_SEQUENTIAL);
+
+ return true;
+ }
+</pre>
+<p>
+To consume an element, a consumer process obtains the children of the root node,
+reads the node with smallest counter value, and returns the element. Note that
+if there is a conflict, then one of the two contending processes won't be able to
+delete the node and the delete operation will throw an exception.</p>
+<p>
+A call to getChildren() returns the list of children in lexicographic order.
+As lexicographic order does not necessary follow the numerical order of the counter
+values, we need to decide which element is the smallest. To decide which one has
+the smallest counter value, we traverse the list, and remove the prefix "element"
+from each one.</p>
+<pre class="code">
+ /**
+ * Remove first element from the queue.
+ *
+ * @return
+ * @throws KeeperException
+ * @throws InterruptedException
+ */
+ int consume() throws KeeperException, InterruptedException{
+ int retvalue = -1;
+ Stat stat = null;
+
+ // Get the first element available
+ while (true) {
+ synchronized (mutex) {
+ List<String> list = zk.getChildren(root, true);
+ if (list.size() == 0) {
+ System.out.println("Going to wait");
+ mutex.wait();
+ } else {
+ Integer min = new Integer(list.get(0).substring(7));
+ for(String s : list){
+ Integer tempValue = new Integer(s.substring(7));
+ //System.out.println("Temporary value: " + tempValue);
+ if(tempValue < min) min = tempValue;
+ }
+ System.out.println("Temporary value: " + root + "/element" + min);
+ byte[] b = zk.getData(root + "/element" + min,
+ false, stat);
+ zk.delete(root + "/element" + min, 0);
+ ByteBuffer buffer = ByteBuffer.wrap(b);
+ retvalue = buffer.getInt();
+
+ return retvalue;
+ }
+ }
+ }
+ }
+ }
+</pre>
+</div>
+
+<a name="sc_sourceListing"></a>
+<h2 class="h3">Complete Source Listing</h2>
+<div class="section">
+<div class="note example">
+<div class="label">SyncPrimitive.Java</div>
+<div class="content">
+
+<title>SyncPrimitive.Java</title>
+
+<pre class="code">
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.nio.ByteBuffer;
+import java.util.List;
+import java.util.Random;
+
+import org.apache.zookeeper.CreateMode;
+import org.apache.zookeeper.KeeperException;
+import org.apache.zookeeper.WatchedEvent;
+import org.apache.zookeeper.Watcher;
+import org.apache.zookeeper.ZooKeeper;
+import org.apache.zookeeper.ZooDefs.Ids;
+import org.apache.zookeeper.data.Stat;
+
+public class SyncPrimitive implements Watcher {
+
+ static ZooKeeper zk = null;
+ static Integer mutex;
+
+ String root;
+
+ SyncPrimitive(String address) {
+ if(zk == null){
+ try {
+ System.out.println("Starting ZK:");
+ zk = new ZooKeeper(address, 3000, this);
+ mutex = new Integer(-1);
+ System.out.println("Finished starting ZK: " + zk);
+ } catch (IOException e) {
+ System.out.println(e.toString());
+ zk = null;
+ }
+ }
+ //else mutex = new Integer(-1);
+ }
+
+ synchronized public void process(WatchedEvent event) {
+ synchronized (mutex) {
+ //System.out.println("Process: " + event.getType());
+ mutex.notify();
+ }
+ }
+
+ /**
+ * Barrier
+ */
+ static public class Barrier extends SyncPrimitive {
+ int size;
+ String name;
+
+ /**
+ * Barrier constructor
+ *
+ * @param address
+ * @param root
+ * @param size
+ */
+ Barrier(String address, String root, int size) {
+ super(address);
+ this.root = root;
+ this.size = size;
+
+ // Create barrier node
+ if (zk != null) {
+ try {
+ Stat s = zk.exists(root, false);
+ if (s == null) {
+ zk.create(root, new byte[0], Ids.OPEN_ACL_UNSAFE,
+ CreateMode.PERSISTENT);
+ }
+ } catch (KeeperException e) {
+ System.out
+ .println("Keeper exception when instantiating queue: "
+ + e.toString());
+ } catch (InterruptedException e) {
+ System.out.println("Interrupted exception");
+ }
+ }
+
+ // My node name
+ try {
+ name = new String(InetAddress.getLocalHost().getCanonicalHostName().toString());
+ } catch (UnknownHostException e) {
+ System.out.println(e.toString());
+ }
+
+ }
+
+ /**
+ * Join barrier
+ *
+ * @return
+ * @throws KeeperException
+ * @throws InterruptedException
+ */
+
+ boolean enter() throws KeeperException, InterruptedException{
+ zk.create(root + "/" + name, new byte[0], Ids.OPEN_ACL_UNSAFE,
+ CreateMode.EPHEMERAL_SEQUENTIAL);
+ while (true) {
+ synchronized (mutex) {
+ List<String> list = zk.getChildren(root, true);
+
+ if (list.size() < size) {
+ mutex.wait();
+ } else {
+ return true;
+ }
+ }
+ }
+ }
+
+ /**
+ * Wait until all reach barrier
+ *
+ * @return
+ * @throws KeeperException
+ * @throws InterruptedException
+ */
+
+ boolean leave() throws KeeperException, InterruptedException{
+ zk.delete(root + "/" + name, 0);
+ while (true) {
+ synchronized (mutex) {
+ List<String> list = zk.getChildren(root, true);
+ if (list.size() > 0) {
+ mutex.wait();
+ } else {
+ return true;
+ }
+ }
+ }
+ }
+ }
+
+ /**
+ * Producer-Consumer queue
+ */
+ static public class Queue extends SyncPrimitive {
+
+ /**
+ * Constructor of producer-consumer queue
+ *
+ * @param address
+ * @param name
+ */
+ Queue(String address, String name) {
+ super(address);
+ this.root = name;
+ // Create ZK node name
+ if (zk != null) {
+ try {
+ Stat s = zk.exists(root, false);
+ if (s == null) {
+ zk.create(root, new byte[0], Ids.OPEN_ACL_UNSAFE,
+ CreateMode.PERSISTENT);
+ }
+ } catch (KeeperException e) {
+ System.out
+ .println("Keeper exception when instantiating queue: "
+ + e.toString());
+ } catch (InterruptedException e) {
+ System.out.println("Interrupted exception");
+ }
+ }
+ }
+
+ /**
+ * Add element to the queue.
+ *
+ * @param i
+ * @return
+ */
+
+ boolean produce(int i) throws KeeperException, InterruptedException{
+ ByteBuffer b = ByteBuffer.allocate(4);
+ byte[] value;
+
+ // Add child with value i
+ b.putInt(i);
+ value = b.array();
+ zk.create(root + "/element", value, Ids.OPEN_ACL_UNSAFE,
+ CreateMode.PERSISTENT_SEQUENTIAL);
+
+ return true;
+ }
+
+
+ /**
+ * Remove first element from the queue.
+ *
+ * @return
+ * @throws KeeperException
+ * @throws InterruptedException
+ */
+ int consume() throws KeeperException, InterruptedException{
+ int retvalue = -1;
+ Stat stat = null;
+
+ // Get the first element available
+ while (true) {
+ synchronized (mutex) {
+ List<String> list = zk.getChildren(root, true);
+ if (list.size() == 0) {
+ System.out.println("Going to wait");
+ mutex.wait();
+ } else {
+ Integer min = new Integer(list.get(0).substring(7));
+ for(String s : list){
+ Integer tempValue = new Integer(s.substring(7));
+ //System.out.println("Temporary value: " + tempValue);
+ if(tempValue < min) min = tempValue;
+ }
+ System.out.println("Temporary value: " + root + "/element" + min);
+ byte[] b = zk.getData(root + "/element" + min,
+ false, stat);
+ zk.delete(root + "/element" + min, 0);
+ ByteBuffer buffer = ByteBuffer.wrap(b);
+ retvalue = buffer.getInt();
+
+ return retvalue;
+ }
+ }
+ }
+ }
+ }
+
+ public static void main(String args[]) {
+ if (args[0].equals("qTest"))
+ queueTest(args);
+ else
+ barrierTest(args);
+
+ }
+
+ public static void queueTest(String args[]) {
+ Queue q = new Queue(args[1], "/app1");
+
+ System.out.println("Input: " + args[1]);
+ int i;
+ Integer max = new Integer(args[2]);
+
+ if (args[3].equals("p")) {
+ System.out.println("Producer");
+ for (i = 0; i < max; i++)
+ try{
+ q.produce(10 + i);
+ } catch (KeeperException e){
+
+ } catch (InterruptedException e){
+
+ }
+ } else {
+ System.out.println("Consumer");
+
+ for (i = 0; i < max; i++) {
+ try{
+ int r = q.consume();
+ System.out.println("Item: " + r);
+ } catch (KeeperException e){
+ i--;
+ } catch (InterruptedException e){
+
+ }
+ }
+ }
+ }
+
+ public static void barrierTest(String args[]) {
+ Barrier b = new Barrier(args[1], "/b1", new Integer(args[2]));
+ try{
+ boolean flag = b.enter();
+ System.out.println("Entered barrier: " + args[2]);
+ if(!flag) System.out.println("Error when entering the barrier");
+ } catch (KeeperException e){
+
+ } catch (InterruptedException e){
+
+ }
+
+ // Generate random integer
+ Random rand = new Random();
+ int r = rand.nextInt(100);
+ // Loop for rand iterations
+ for (int i = 0; i < r; i++) {
+ try {
+ Thread.sleep(100);
+ } catch (InterruptedException e) {
+
+ }
+ }
+ try{
+ b.leave();
+ } catch (KeeperException e){
+
+ } catch (InterruptedException e){
+
+ }
+ System.out.println("Left barrier");
+ }
+}
+</pre>
+</div>
+</div>
+</div>
+
+
+<p align="right">
+<font size="-2"></font>
+</p>
+</div>
+<!--+
+ |end content
+ +-->
+<div class="clearboth"> </div>
+</div>
+<div id="footer">
+<!--+
+ |start bottomstrip
+ +-->
+<div class="lastmodified">
+<script type="text/javascript"><!--
+document.write("Last Published: " + document.lastModified);
+// --></script>
+</div>
+<div class="copyright">
+ Copyright ©
+ 2008-2013 <a href="http://www.apache.org/licenses/">The Apache Software Foundation.</a>
+</div>
+<!--+
+ |end bottomstrip
+ +-->
+</div>
+</body>
+</html>
Added: websites/staging/zookeeper/trunk/content/doc/r3.5.1-alpha/zookeeperTutorial.pdf
==============================================================================
Binary file - no diff available.
Propchange: websites/staging/zookeeper/trunk/content/doc/r3.5.1-alpha/zookeeperTutorial.pdf
------------------------------------------------------------------------------
svn:mime-type = application/pdf
Modified: websites/staging/zookeeper/trunk/content/index.html
==============================================================================
--- websites/staging/zookeeper/trunk/content/index.html (original)
+++ websites/staging/zookeeper/trunk/content/index.html Thu Sep 3 05:08:27 2015
@@ -120,6 +120,7 @@
<h3>Documentation</h3>
<ul>
+<li><a href="./doc/r3.5.1-alpha">Release 3.5.1-alpha</a></li>
<li><a href="./doc/r3.5.0-alpha">Release 3.5.0-alpha</a></li>
<li><a href="./doc/r3.4.6">Release 3.4.6(stable)</a></li>
<li><a href="./doc/r3.4.6">Release 3.4.6(current)</a></li>
Modified: websites/staging/zookeeper/trunk/content/irc.html
==============================================================================
--- websites/staging/zookeeper/trunk/content/irc.html (original)
+++ websites/staging/zookeeper/trunk/content/irc.html Thu Sep 3 05:08:27 2015
@@ -96,6 +96,7 @@
<h3>Documentation</h3>
<ul>
+<li><a href="./doc/r3.5.1-alpha">Release 3.5.1-alpha</a></li>
<li><a href="./doc/r3.5.0-alpha">Release 3.5.0-alpha</a></li>
<li><a href="./doc/r3.4.6">Release 3.4.6(stable)</a></li>
<li><a href="./doc/r3.4.6">Release 3.4.6(current)</a></li>
Modified: websites/staging/zookeeper/trunk/content/lists.html
==============================================================================
--- websites/staging/zookeeper/trunk/content/lists.html (original)
+++ websites/staging/zookeeper/trunk/content/lists.html Thu Sep 3 05:08:27 2015
@@ -136,6 +136,7 @@ In order to post to the list, it is nece
<h3>Documentation</h3>
<ul>
+<li><a href="./doc/r3.5.1-alpha">Release 3.5.1-alpha</a></li>
<li><a href="./doc/r3.5.0-alpha">Release 3.5.0-alpha</a></li>
<li><a href="./doc/r3.4.6">Release 3.4.6(stable)</a></li>
<li><a href="./doc/r3.4.6">Release 3.4.6(current)</a></li>
Modified: websites/staging/zookeeper/trunk/content/privacy.html
==============================================================================
--- websites/staging/zookeeper/trunk/content/privacy.html (original)
+++ websites/staging/zookeeper/trunk/content/privacy.html Thu Sep 3 05:08:27 2015
@@ -108,6 +108,7 @@
<h3>Documentation</h3>
<ul>
+<li><a href="./doc/r3.5.1-alpha">Release 3.5.1-alpha</a></li>
<li><a href="./doc/r3.5.0-alpha">Release 3.5.0-alpha</a></li>
<li><a href="./doc/r3.4.6">Release 3.4.6(stable)</a></li>
<li><a href="./doc/r3.4.6">Release 3.4.6(current)</a></li>
Modified: websites/staging/zookeeper/trunk/content/releases.html
==============================================================================
--- websites/staging/zookeeper/trunk/content/releases.html (original)
+++ websites/staging/zookeeper/trunk/content/releases.html Thu Sep 3 05:08:27 2015
@@ -75,6 +75,12 @@
<h2 id="news">News</h2>
+<h3>31 August, 2015: release 3.5.1-alpha available</h3>
+
+<p>This is an alpha quality release that contains many bug fixes and improvements. It also introduces a few new features, including container znodes and <span class="caps">SSL </span>support for client-server communication.</p>
+
+<p>See the <a href="http://zookeeper.apache.org/doc/r3.5.1-alpha/releasenotes.html">ZooKeeper 3.5.1-alpha Release Notes</a> for details.</p>
+
<h3>6 August, 2014: release 3.5.0-alpha available</h3>
<p>This release is alpha quality and contains many improvements, new features, bug fixes and optimizations.</p>
@@ -247,6 +253,7 @@ In case you are already using 3.4.0 rele
<h3>Documentation</h3>
<ul>
+<li><a href="./doc/r3.5.1-alpha">Release 3.5.1-alpha</a></li>
<li><a href="./doc/r3.5.0-alpha">Release 3.5.0-alpha</a></li>
<li><a href="./doc/r3.4.6">Release 3.4.6(stable)</a></li>
<li><a href="./doc/r3.4.6">Release 3.4.6(current)</a></li>
Modified: websites/staging/zookeeper/trunk/content/svn.html
==============================================================================
--- websites/staging/zookeeper/trunk/content/svn.html (original)
+++ websites/staging/zookeeper/trunk/content/svn.html Thu Sep 3 05:08:27 2015
@@ -106,6 +106,7 @@
<h3>Documentation</h3>
<ul>
+<li><a href="./doc/r3.5.1-alpha">Release 3.5.1-alpha</a></li>
<li><a href="./doc/r3.5.0-alpha">Release 3.5.0-alpha</a></li>
<li><a href="./doc/r3.4.6">Release 3.4.6(stable)</a></li>
<li><a href="./doc/r3.4.6">Release 3.4.6(current)</a></li>