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Posted to commits@jclouds.apache.org by ev...@apache.org on 2014/01/03 17:43:06 UTC

git commit: Examples for Rackspace Cloud Queues

Updated Branches:
  refs/heads/master f16743ddf -> 9dc24d239


Examples for Rackspace Cloud Queues


Project: http://git-wip-us.apache.org/repos/asf/jclouds-examples/repo
Commit: http://git-wip-us.apache.org/repos/asf/jclouds-examples/commit/9dc24d23
Tree: http://git-wip-us.apache.org/repos/asf/jclouds-examples/tree/9dc24d23
Diff: http://git-wip-us.apache.org/repos/asf/jclouds-examples/diff/9dc24d23

Branch: refs/heads/master
Commit: 9dc24d2391f716dc9eceac633aa8e0f0ff651b55
Parents: f16743d
Author: Everett Toews <ev...@rackspace.com>
Authored: Tue Dec 24 11:56:19 2013 -0600
Committer: Everett Toews <ev...@rackspace.com>
Committed: Fri Jan 3 10:41:39 2014 -0600

----------------------------------------------------------------------
 rackspace/README.md                             |   5 +
 rackspace/pom.xml                               |  10 +
 .../jclouds/examples/rackspace/SmokeTest.java   |   7 +
 .../rackspace/cloudqueues/Constants.java        |  46 ++++
 .../rackspace/cloudqueues/ProducerConsumer.java | 220 ++++++++++++++++++
 .../rackspace/cloudqueues/PublishSubscribe.java | 231 +++++++++++++++++++
 .../rackspace/cloudqueues/StreamMessages.java   | 190 +++++++++++++++
 7 files changed, 709 insertions(+)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/jclouds-examples/blob/9dc24d23/rackspace/README.md
----------------------------------------------------------------------
diff --git a/rackspace/README.md b/rackspace/README.md
index f63e3fa..ad2e876 100644
--- a/rackspace/README.md
+++ b/rackspace/README.md
@@ -71,6 +71,11 @@ The [clouddatabases package](https://github.com/jclouds/jclouds-examples/tree/ma
   * [TestDatabase.java](https://github.com/jclouds/jclouds-examples/blob/master/rackspace/src/main/java/org/jclouds/examples/rackspace/clouddatabases/TestDatabase.java) - An example of connecting to the database from the public Internet and making a simple request.
   * Other examples include deleting instances, databases, and users, and granting root access.
 
+The [cloudqueues package](https://github.com/jclouds/jclouds-examples/tree/master/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues) demonstrates how to accomplish common tasks for working with queues in the cloud.
+
+  * [ProducerConsumer.java](https://github.com/jclouds/jclouds-examples/blob/master/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/ProducerConsumer.java) - An example of the Producer/Consumer pattern.
+  * [PublishSubscribe.java](https://github.com/jclouds/jclouds-examples/blob/master/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/PublishSubscribe.java) - An example of the Publish/Subscribe pattern.
+  * [StreamMessages.java](https://github.com/jclouds/jclouds-examples/blob/master/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/StreamMessages.java) - An example of streaming messages off of a queue.
 
 ## Command Line
 

http://git-wip-us.apache.org/repos/asf/jclouds-examples/blob/9dc24d23/rackspace/pom.xml
----------------------------------------------------------------------
diff --git a/rackspace/pom.xml b/rackspace/pom.xml
index 940749d..ffbca61 100644
--- a/rackspace/pom.xml
+++ b/rackspace/pom.xml
@@ -74,6 +74,11 @@
       <artifactId>rackspace-clouddatabases-us</artifactId>
       <version>${jclouds.version}</version>
     </dependency>
+    <dependency>
+      <groupId>org.apache.jclouds.labs</groupId>
+      <artifactId>rackspace-cloudqueues-us</artifactId>
+      <version>${jclouds.version}</version>
+    </dependency>
     <!-- UK -->
     <dependency>
       <groupId>org.apache.jclouds.provider</groupId>
@@ -107,6 +112,11 @@
     </dependency>
     <dependency>
       <groupId>org.apache.jclouds.labs</groupId>
+      <artifactId>rackspace-cloudqueues-uk</artifactId>
+      <version>${jclouds.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.jclouds.labs</groupId>
       <artifactId>rackspace-autoscale</artifactId>
       <version>${jclouds.version}</version>
     </dependency>

http://git-wip-us.apache.org/repos/asf/jclouds-examples/blob/9dc24d23/rackspace/src/main/java/org/jclouds/examples/rackspace/SmokeTest.java
----------------------------------------------------------------------
diff --git a/rackspace/src/main/java/org/jclouds/examples/rackspace/SmokeTest.java b/rackspace/src/main/java/org/jclouds/examples/rackspace/SmokeTest.java
index e711831..97a6a73 100644
--- a/rackspace/src/main/java/org/jclouds/examples/rackspace/SmokeTest.java
+++ b/rackspace/src/main/java/org/jclouds/examples/rackspace/SmokeTest.java
@@ -24,6 +24,9 @@ import org.jclouds.examples.rackspace.cloudblockstorage.*;
 import org.jclouds.examples.rackspace.clouddns.*;
 import org.jclouds.examples.rackspace.cloudfiles.*;
 import org.jclouds.examples.rackspace.cloudloadbalancers.*;
+import org.jclouds.examples.rackspace.cloudqueues.ProducerConsumer;
+import org.jclouds.examples.rackspace.cloudqueues.PublishSubscribe;
+import org.jclouds.examples.rackspace.cloudqueues.StreamMessages;
 import org.jclouds.examples.rackspace.cloudservers.*;
 import org.jclouds.examples.rackspace.clouddatabases.*;
 import org.jclouds.examples.rackspace.autoscale.*;
@@ -111,5 +114,9 @@ public class SmokeTest {
       CreateWebhook.main(args);
       ExecuteWebhook.main(args);
       AutoscaleCleanup.main(args);
+
+      ProducerConsumer.main(args);
+      PublishSubscribe.main(args);
+      StreamMessages.main(args);
    }
 }

http://git-wip-us.apache.org/repos/asf/jclouds-examples/blob/9dc24d23/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/Constants.java
----------------------------------------------------------------------
diff --git a/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/Constants.java b/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/Constants.java
new file mode 100644
index 0000000..5ccd8be
--- /dev/null
+++ b/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/Constants.java
@@ -0,0 +1,46 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ */
+package org.jclouds.examples.rackspace.cloudqueues;
+
+import java.util.UUID;
+
+/**
+ * Constants used by the Rackspace Examples.
+ *
+ * @author Everett Toews
+ */
+public interface Constants {
+   // The provider configures jclouds To use the Rackspace Cloud (US)
+   // To use the Rackspace Cloud (UK) set the system property or default value to "rackspace-cloudqueues-uk"
+   final String PROVIDER = System.getProperty("provider.cbs", "rackspace-cloudqueues-us");
+   final String ZONE = System.getProperty("zone", "IAD");
+
+   final UUID PRODUCER_ID = UUID.fromString("3381af92-2b9e-11e3-b191-71861300734a");
+   final UUID CONSUMER_ID = UUID.fromString("3381af92-2b9e-11e3-b191-71861300734b");
+   final UUID PUBLISHER_ID = UUID.fromString("3381af92-2b9e-11e3-b191-71861300734c");
+   final UUID SUBSCRIBER_ID = UUID.fromString("3381af92-2b9e-11e3-b191-71861300734d");
+   final String NAME = "jclouds-example";
+
+   final int NUM_THREADS = 3;
+
+   final String PRODUCER_NAME = "producer.name";
+   final String PUBLISHER_NAME = "publisher.name";
+   final String MESSAGE_TEXT = "message.text";
+   final String MESSAGE_NUM = "message.num";
+}

http://git-wip-us.apache.org/repos/asf/jclouds-examples/blob/9dc24d23/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/ProducerConsumer.java
----------------------------------------------------------------------
diff --git a/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/ProducerConsumer.java b/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/ProducerConsumer.java
new file mode 100644
index 0000000..c578298
--- /dev/null
+++ b/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/ProducerConsumer.java
@@ -0,0 +1,220 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ */
+package org.jclouds.examples.rackspace.cloudqueues;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.io.Closeables;
+import org.jclouds.ContextBuilder;
+import org.jclouds.openstack.marconi.v1.MarconiApi;
+import org.jclouds.openstack.marconi.v1.domain.CreateMessage;
+import org.jclouds.openstack.marconi.v1.domain.Message;
+import org.jclouds.openstack.marconi.v1.features.ClaimApi;
+import org.jclouds.openstack.marconi.v1.features.MessageApi;
+import org.jclouds.openstack.marconi.v1.features.QueueApi;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.List;
+import java.util.Properties;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+
+import static java.lang.String.format;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.CONSUMER_ID;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.MESSAGE_NUM;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.MESSAGE_TEXT;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.NAME;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.NUM_THREADS;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.PRODUCER_ID;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.PRODUCER_NAME;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.PROVIDER;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.ZONE;
+
+/**
+ * Setting up a Producer/Consumer model in Cloud Queues consists of posting messages to your queue, consumers claiming
+ * messages from that queue, and then deleting the completed message.
+ *
+ * The producer-consumer mode has the following characteristics:
+ *
+ * 1. Messages are acted upon by one (and only one) worker.
+ * 2. Worker must delete message when done.
+ * 3. TTL restores message to unclaimed state if worker never finishes.
+ * 4. Ideal for dispatching jobs to multiple processors.
+ *
+ * This mode is ideal for dispatching jobs to multiple processors.
+ *
+ * @author Everett Toews
+ */
+public class ProducerConsumer implements Closeable {
+   private final MarconiApi marconiApi;
+   private final QueueApi queueApi;
+
+   /**
+    * To get a username and API key see
+    * http://apache.jclouds.org/documentation/quickstart/rackspace/
+    *
+    * The first argument (args[0]) must be your username
+    * The second argument (args[1]) must be your API key
+    */
+   public static void main(String[] args) throws IOException {
+      ProducerConsumer producerConsumer = new ProducerConsumer(args[0], args[1]);
+
+      try {
+         producerConsumer.createQueue();
+         producerConsumer.produceAndConsume();
+         producerConsumer.deleteQueue();
+      }
+      catch (Exception e) {
+         e.printStackTrace();
+      }
+      finally {
+         producerConsumer.close();
+      }
+   }
+
+   public ProducerConsumer(String username, String apiKey) {
+      // If this application we're running *inside* the Rackspace Cloud, you would want to use the InternalUrlModule
+      // as below to have all of the Cloud Queues traffic go over the internal Rackspace Cloud network.
+      // Iterable<Module> modules = ImmutableSet.<Module> of(new InternalUrlModule());
+
+      marconiApi = ContextBuilder.newBuilder(PROVIDER)
+            .credentials(username, apiKey)
+            // .modules(modules)
+            .buildApi(MarconiApi.class);
+      queueApi = marconiApi.getQueueApiForZoneAndClient(ZONE, PRODUCER_ID);
+   }
+
+   private void createQueue() {
+      queueApi.create(NAME);
+   }
+
+   private void produceAndConsume() throws ExecutionException, InterruptedException {
+      System.out.format("Producer Consumer%n");
+
+      ExecutorService executorService = Executors.newFixedThreadPool(NUM_THREADS);
+
+      executorService.execute(new Consumer("1"));
+      executorService.execute(new Consumer("2"));
+
+      Future producerFuture = executorService.submit(new Producer("1"));
+      producerFuture.get();
+
+      executorService.shutdown();
+   }
+
+   private void deleteQueue() {
+      queueApi.delete(NAME);
+   }
+
+   /**
+    * Always close your service when you're done with it.
+    *
+    * Note that closing quietly like this is not necessary in Java 7.
+    * You would use try-with-resources in the main method instead.
+    */
+   public void close() throws IOException {
+      Closeables.close(marconiApi, true);
+   }
+
+   private void sleep(long millis) {
+      try {
+         Thread.sleep(millis);
+      }
+      catch (InterruptedException e) {
+         e.printStackTrace();
+      }
+   }
+
+   public class Producer implements Runnable {
+      private final String producerName;
+      private final MessageApi messageApi;
+
+      protected Producer(String producerName) {
+         this.producerName = producerName;
+         messageApi = marconiApi.getMessageApiForZoneAndClientAndQueue(ZONE, PRODUCER_ID, NAME);
+      }
+
+      public void run() {
+         for (int i = 0; i < 32; i++) {
+            messageApi.create(produce(i));
+            sleep(250);
+         }
+      }
+
+      private List<CreateMessage> produce(int messageNum) {
+         StringBuilder bodyBuilder = new StringBuilder();
+         bodyBuilder.append(format("%s=%s%n", PRODUCER_NAME, producerName))
+                    .append(format("%s=%d%n", MESSAGE_NUM, messageNum))
+                    .append(format("%s=%s%n", MESSAGE_TEXT, "Queue This Way"));
+
+         CreateMessage message = CreateMessage.builder().ttl(300).body(bodyBuilder.toString()).build();
+
+         System.out.format("  Producer %s Message %s:%d%n", producerName, producerName, messageNum);
+
+         return ImmutableList.of(message);
+      }
+   }
+
+   public class Consumer implements Runnable {
+      private final String consumerName;
+      private final MessageApi messageApi;
+      private final ClaimApi claimApi;
+
+      protected Consumer(String consumerName) {
+         this.consumerName = consumerName;
+         messageApi = marconiApi.getMessageApiForZoneAndClientAndQueue(ZONE, CONSUMER_ID, NAME);
+         claimApi = marconiApi.getClaimApiForZoneAndClientAndQueue(ZONE, CONSUMER_ID, NAME);
+      }
+
+      public void run() {
+         for (int i = 0; i < 32; i++) {
+            List<Message> messages = claimApi.claim(120, 60, 2);
+            consume(messages);
+            sleep(300);
+         }
+      }
+
+      private void consume(List<Message> messages) {
+         for (Message message : messages) {
+            Properties props = loadStringProperties(message.getBody());
+
+            System.out.format("  Consumer %s Message %s:%s (%s)%n", consumerName,
+                  props.getProperty(PRODUCER_NAME), props.getProperty(MESSAGE_NUM), props.getProperty(MESSAGE_TEXT));
+
+            messageApi.deleteByClaim(message.getId(), message.getClaimId().get());
+         }
+      }
+
+      private Properties loadStringProperties(String body) {
+         Properties properties = new Properties();
+
+         try {
+            properties.load(new StringReader(body));
+         }
+         catch (IOException e) {
+            // IOException will never occur here because we're loading directly from a String
+         }
+
+         return properties;
+      }
+   }
+}

http://git-wip-us.apache.org/repos/asf/jclouds-examples/blob/9dc24d23/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/PublishSubscribe.java
----------------------------------------------------------------------
diff --git a/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/PublishSubscribe.java b/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/PublishSubscribe.java
new file mode 100644
index 0000000..63fd70d
--- /dev/null
+++ b/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/PublishSubscribe.java
@@ -0,0 +1,231 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ */
+package org.jclouds.examples.rackspace.cloudqueues;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.io.Closeables;
+import org.jclouds.ContextBuilder;
+import org.jclouds.openstack.marconi.v1.MarconiApi;
+import org.jclouds.openstack.marconi.v1.domain.CreateMessage;
+import org.jclouds.openstack.marconi.v1.domain.Message;
+import org.jclouds.openstack.marconi.v1.domain.MessageStream;
+import org.jclouds.openstack.marconi.v1.features.MessageApi;
+import org.jclouds.openstack.marconi.v1.features.QueueApi;
+import org.jclouds.openstack.marconi.v1.options.StreamMessagesOptions;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.List;
+import java.util.Properties;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+
+import static java.lang.String.format;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.MESSAGE_NUM;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.MESSAGE_TEXT;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.NAME;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.NUM_THREADS;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.PROVIDER;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.PUBLISHER_ID;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.PUBLISHER_NAME;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.SUBSCRIBER_ID;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.ZONE;
+import static org.jclouds.openstack.marconi.v1.options.StreamMessagesOptions.Builder.limit;
+
+/**
+ * Characteristics of the Publish/Subscribe model in Cloud Queues are:
+ *
+ * 1. All subscribers listen to the messages on the queue.
+ * 2. Messages are not claimed.
+ * 3. Subscribers can send a marker/cursor to skip messages already seen.
+ * 4. TTL deletes messages eventually.
+ *
+ * Ideal for notification of events to multiple listeners at once.
+ *
+ * @author Everett Toews
+ */
+public class PublishSubscribe implements Closeable {
+   private final MarconiApi marconiApi;
+   private final QueueApi queueApi;
+
+   /**
+    * To get a username and API key see
+    * http://apache.jclouds.org/documentation/quickstart/rackspace/
+    *
+    * The first argument (args[0]) must be your username
+    * The second argument (args[1]) must be your API key
+    */
+   public static void main(String[] args) throws IOException {
+      PublishSubscribe publishSubscribe = new PublishSubscribe(args[0], args[1]);
+
+      try {
+         publishSubscribe.createQueue();
+         publishSubscribe.publishAndSubscribe();
+         publishSubscribe.deleteQueue();
+      }
+      catch (Exception e) {
+         e.printStackTrace();
+      }
+      finally {
+         publishSubscribe.close();
+      }
+   }
+
+   public PublishSubscribe(String username, String apiKey) {
+      // If this application we're running *inside* the Rackspace Cloud, you would want to use the InternalUrlModule
+      // as below to have all of the Cloud Queues traffic go over the internal Rackspace Cloud network.
+      // Iterable<Module> modules = ImmutableSet.<Module> of(new InternalUrlModule());
+
+      marconiApi = ContextBuilder.newBuilder(PROVIDER)
+            .credentials(username, apiKey)
+            // .modules(modules)
+            .buildApi(MarconiApi.class);
+      queueApi = marconiApi.getQueueApiForZoneAndClient(ZONE, PUBLISHER_ID);
+   }
+
+   private void createQueue() {
+      queueApi.create(NAME);
+   }
+
+   private void publishAndSubscribe() throws ExecutionException, InterruptedException {
+      System.out.format("Publisher Subcriber%n");
+
+      ExecutorService executorService = Executors.newFixedThreadPool(NUM_THREADS);
+
+      executorService.execute(new Subscriber("1"));
+      executorService.execute(new Subscriber("2"));
+
+      Future publisherFuture = executorService.submit(new Publisher("1"));
+      publisherFuture.get();
+
+      executorService.shutdown();
+   }
+
+   private void deleteQueue() {
+      queueApi.delete(NAME);
+   }
+
+   /**
+    * Always close your service when you're done with it.
+    *
+    * Note that closing quietly like this is not necessary in Java 7.
+    * You would use try-with-resources in the main method instead.
+    */
+   public void close() throws IOException {
+      Closeables.close(marconiApi, true);
+   }
+
+   private void sleep(long millis) {
+      try {
+         Thread.sleep(millis);
+      }
+      catch (InterruptedException e) {
+         e.printStackTrace();
+      }
+   }
+
+   public class Publisher implements Runnable {
+      private final String publisherName;
+      private final MessageApi messageApi;
+
+      protected Publisher(String publisherName) {
+         this.publisherName = publisherName;
+         messageApi = marconiApi.getMessageApiForZoneAndClientAndQueue(ZONE, PUBLISHER_ID, NAME);
+      }
+
+      public void run() {
+         for (int i = 0; i < 32; i++) {
+            messageApi.create(publish(i));
+            sleep(200);
+         }
+      }
+
+      private List<CreateMessage> publish(int messageNum) {
+         StringBuilder bodyBuilder = new StringBuilder();
+         bodyBuilder.append(format("%s=%s%n", PUBLISHER_NAME, publisherName))
+                    .append(format("%s=%d%n", MESSAGE_NUM, messageNum))
+                    .append(format("%s=%s%n", MESSAGE_TEXT, "Read all about it"));
+
+         CreateMessage message = CreateMessage.builder().ttl(300).body(bodyBuilder.toString()).build();
+
+         System.out.format("  Publisher  %s Message %s:%d%n", publisherName, publisherName, messageNum);
+
+         return ImmutableList.of(message);
+      }
+   }
+
+   public class Subscriber implements Runnable {
+      private final String subscriberName;
+      private final MessageApi messageApi;
+      private int consecutiveSleepCount = 0;
+
+      protected Subscriber(String subscriberName) {
+         this.subscriberName = subscriberName;
+         messageApi = marconiApi.getMessageApiForZoneAndClientAndQueue(ZONE, SUBSCRIBER_ID, NAME);
+      }
+
+      /**
+       * Process messages off the queue until we haven't seen any messages 3 times in a row.
+       */
+      public void run() {
+         StreamMessagesOptions streamMessagesOptions = limit(2);
+         MessageStream stream = messageApi.stream(streamMessagesOptions);
+
+         while (consecutiveSleepCount < 3) {
+            if (stream.nextMarker().isPresent()) {
+               process(stream);
+               consecutiveSleepCount = 0;
+               streamMessagesOptions = stream.nextStreamOptions();
+            }
+            else {
+               sleep(150);
+               consecutiveSleepCount++;
+               // leave the streamMessagesOptions from the previous loop as is so it can be used in the next loop
+            }
+
+            stream = messageApi.stream(streamMessagesOptions);
+         }
+      }
+
+      private void process(MessageStream messageStream) {
+         for (Message message : messageStream) {
+            Properties props = loadStringProperties(message.getBody());
+
+            System.out.format("  Subscriber %s Message %s:%s (%s)%n", subscriberName,
+                  props.getProperty(PUBLISHER_NAME), props.getProperty(MESSAGE_NUM), props.getProperty(MESSAGE_TEXT));
+         }
+      }
+
+      private Properties loadStringProperties(String body) {
+         Properties properties = new Properties();
+
+         try {
+            properties.load(new StringReader(body));
+         }
+         catch (IOException e) {
+            // IOException will never occur here because we're loading directly from a String
+         }
+
+         return properties;
+      }
+   }
+}

http://git-wip-us.apache.org/repos/asf/jclouds-examples/blob/9dc24d23/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/StreamMessages.java
----------------------------------------------------------------------
diff --git a/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/StreamMessages.java b/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/StreamMessages.java
new file mode 100644
index 0000000..d096ad4
--- /dev/null
+++ b/rackspace/src/main/java/org/jclouds/examples/rackspace/cloudqueues/StreamMessages.java
@@ -0,0 +1,190 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ */
+package org.jclouds.examples.rackspace.cloudqueues;
+
+import com.google.common.collect.Lists;
+import com.google.common.io.Closeables;
+import org.jclouds.ContextBuilder;
+import org.jclouds.openstack.marconi.v1.MarconiApi;
+import org.jclouds.openstack.marconi.v1.domain.CreateMessage;
+import org.jclouds.openstack.marconi.v1.domain.Message;
+import org.jclouds.openstack.marconi.v1.domain.MessageStream;
+import org.jclouds.openstack.marconi.v1.features.MessageApi;
+import org.jclouds.openstack.marconi.v1.features.QueueApi;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.List;
+import java.util.Properties;
+import java.util.concurrent.ExecutionException;
+
+import static java.lang.String.format;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.CONSUMER_ID;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.MESSAGE_NUM;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.MESSAGE_TEXT;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.NAME;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.PRODUCER_ID;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.PRODUCER_NAME;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.PROVIDER;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.PUBLISHER_ID;
+import static org.jclouds.examples.rackspace.cloudqueues.Constants.ZONE;
+import static org.jclouds.openstack.marconi.v1.options.StreamMessagesOptions.Builder.marker;
+
+/**
+ * Stream messages off of a queue. In a very active queue it's possible that you could continuously stream messages
+ * indefinitely.
+ *
+ * You can also resume where you left off by remembering the marker.
+ *
+ * @author Everett Toews
+ */
+public class StreamMessages implements Closeable {
+   private final MarconiApi marconiApi;
+   private final QueueApi queueApi;
+
+   /**
+    * To get a username and API key see
+    * http://apache.jclouds.org/documentation/quickstart/rackspace/
+    *
+    * The first argument (args[0]) must be your username
+    * The second argument (args[1]) must be your API key
+    */
+   public static void main(String[] args) throws IOException {
+      StreamMessages streamMessages = new StreamMessages(args[0], args[1]);
+
+      try {
+         streamMessages.createQueue();
+         streamMessages.createMessages();
+         streamMessages.streamMessages();
+         streamMessages.deleteQueue();
+      } catch (Exception e) {
+         e.printStackTrace();
+      } finally {
+         streamMessages.close();
+      }
+   }
+
+   public StreamMessages(String username, String apiKey) {
+      // If this application we're running *inside* the Rackspace Cloud, you would want to use the InternalUrlModule
+      // as below to have all of the Cloud Queues traffic go over the internal Rackspace Cloud network.
+      // Iterable<Module> modules = ImmutableSet.<Module> of(new InternalUrlModule());
+
+      marconiApi = ContextBuilder.newBuilder(PROVIDER)
+            .credentials(username, apiKey)
+            // .modules(modules)
+            .buildApi(MarconiApi.class);
+      queueApi = marconiApi.getQueueApiForZoneAndClient(ZONE, PUBLISHER_ID);
+   }
+
+   private void createQueue() {
+      queueApi.create(NAME);
+   }
+
+   private void createMessages() throws ExecutionException, InterruptedException {
+      System.out.format("Create Messages%n");
+
+      MessageApi messageApi = marconiApi.getMessageApiForZoneAndClientAndQueue(ZONE, PRODUCER_ID, NAME);
+      List<CreateMessage> createMessages = Lists.newArrayList();
+
+      for (int i=0; i < 10; i++) {
+         for (int j=0; j < 10; j++) {
+            StringBuilder bodyBuilder = new StringBuilder();
+            bodyBuilder.append(format("%s=%s%n", PRODUCER_NAME, PRODUCER_ID))
+                       .append(format("%s=%d%n", MESSAGE_NUM, i*10+j))
+                       .append(format("%s=%s%n", MESSAGE_TEXT, "Hear Ye! Hear Ye!"));
+
+            CreateMessage createMessage = CreateMessage.builder().ttl(300).body(bodyBuilder.toString()).build();
+            createMessages.add(createMessage);
+         }
+
+         messageApi.create(createMessages);
+
+         System.out.format("  Created %d messages%n", createMessages.size());
+
+         createMessages.clear();
+      }
+   }
+
+   private void streamMessages() {
+      System.out.format("Stream Messages%n");
+
+      MessageApi messageApi = marconiApi.getMessageApiForZoneAndClientAndQueue(ZONE, CONSUMER_ID, NAME);
+      MessageStream stream = messageApi.stream();
+      String marker = "";
+
+      while(stream.nextMarker().isPresent()) {
+         for (Message message: stream) {
+            Properties messageProps = loadStringProperties(message.getBody());
+            int messageNum = Integer.valueOf(messageProps.getProperty(MESSAGE_NUM));
+
+            System.out.format("  Read message %d%n", messageNum);
+
+            if (messageNum == 49) {
+               System.out.format("  Breaking at message %d%n", messageNum);
+               // Breaking here to illustrate how to resume using the marker below
+               break;
+            }
+         }
+
+         marker = stream.nextStreamOptions().getMarker();
+         stream = messageApi.stream(stream.nextStreamOptions());
+      }
+
+      stream = messageApi.stream(marker(marker));
+
+      while(stream.nextMarker().isPresent()) {
+         for (Message message: stream) {
+            Properties messageProps = loadStringProperties(message.getBody());
+            int messageNum = Integer.valueOf(messageProps.getProperty(MESSAGE_NUM));
+
+            System.out.format("  Read message %d%n", messageNum);
+         }
+
+         stream = messageApi.stream(stream.nextStreamOptions());
+      }
+   }
+
+   private void deleteQueue() {
+      queueApi.delete(NAME);
+   }
+
+   private Properties loadStringProperties(String body) {
+      Properties properties = new Properties();
+
+      try {
+         properties.load(new StringReader(body));
+      }
+      catch (IOException e) {
+         // IOException will never occur here because we're loading directly from a String
+      }
+
+      return properties;
+   }
+
+   /**
+    * Always close your service when you're done with it.
+    *
+    * Note that closing quietly like this is not necessary in Java 7.
+    * You would use try-with-resources in the main method instead.
+    */
+   public void close() throws IOException {
+      Closeables.close(marconiApi, true);
+   }
+}