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Subject 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...
Date Thu, 03 Sep 2015 05:08:31 GMT
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 @@
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+        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&lt;String&gt; list = zk.getChildren(root, true);
+
+                    if (list.size() &lt; 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&lt;String&gt; list = zk.getChildren(root, true);
+                        if (list.size() &gt; 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&lt;String&gt; 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 &lt; 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&lt;String&gt; list = zk.getChildren(root, true);
+
+                    if (list.size() &lt; 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&lt;String&gt; list = zk.getChildren(root, true);
+                        if (list.size() &gt; 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&lt;String&gt; 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 &lt; 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 &lt; max; i++)
+                try{
+                    q.produce(10 + i);
+                } catch (KeeperException e){
+
+                } catch (InterruptedException e){
+
+                }
+        } else {
+            System.out.println("Consumer");
+
+            for (i = 0; i &lt; 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 &lt; 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">&nbsp;</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 &copy;
+         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&#40;stable&#41;</a></li>
 <li><a href="./doc/r3.4.6">Release 3.4.6&#40;current&#41;</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&#40;stable&#41;</a></li>
 <li><a href="./doc/r3.4.6">Release 3.4.6&#40;current&#41;</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&#40;stable&#41;</a></li>
 <li><a href="./doc/r3.4.6">Release 3.4.6&#40;current&#41;</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&#40;stable&#41;</a></li>
 <li><a href="./doc/r3.4.6">Release 3.4.6&#40;current&#41;</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&#40;stable&#41;</a></li>
 <li><a href="./doc/r3.4.6">Release 3.4.6&#40;current&#41;</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&#40;stable&#41;</a></li>
 <li><a href="./doc/r3.4.6">Release 3.4.6&#40;current&#41;</a></li>



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