Websphere MQ as a data source for Apache Spark Streaming - apache-spark

Question

I was digging into the possibilities for Websphere MQ as a data source for spark-streaming becuase it is needed in one of our use case.
I got to know that MQTT is the protocol that supports the communication from MQ data structures but since I am a newbie to spark streaming I need some working examples for the same.
Did anyone try to connect the MQ with spark streaming. Please devise the best way for doing so.

Answer 1

So, I am posting here the working code for CustomMQReceiver which connects the Websphere MQ and reads data :
public class CustomMQReciever extends Receiver<String> { String host = null;
int port = -1;
String qm=null;
String qn=null;
String channel=null;
transient Gson gson=new Gson();
transient MQQueueConnection qCon= null;
Enumeration enumeration =null;
public CustomMQReciever(String host , int port, String qm, String channel, String qn) {
super(StorageLevel.MEMORY_ONLY_2());
this.host = host;
this.port = port;
this.qm=qm;
this.qn=qn;
this.channel=channel;
}
public void onStart() {
// Start the thread that receives data over a connection
new Thread() {
#Override public void run() {
try {
initConnection();
receive();
}
catch (JMSException ex)
{
ex.printStackTrace();
}
}
}.start();
}
public void onStop() {
// There is nothing much to do as the thread calling receive()
// is designed to stop by itself isStopped() returns false
}
/** Create a MQ connection and receive data until receiver is stopped */
private void receive() {
System.out.print("Started receiving messages from MQ");
try {
JMSMessage receivedMessage= null;
while (!isStopped() && enumeration.hasMoreElements() )
{
receivedMessage= (JMSMessage) enumeration.nextElement();
String userInput = convertStreamToString(receivedMessage);
//System.out.println("Received data :'" + userInput + "'");
store(userInput);
}
// Restart in an attempt to connect again when server is active again
//restart("Trying to connect again");
stop("No More Messages To read !");
qCon.close();
System.out.println("Queue Connection is Closed");
}
catch(Exception e)
{
e.printStackTrace();
restart("Trying to connect again");
}
catch(Throwable t) {
// restart if there is any other error
restart("Error receiving data", t);
}
}
public void initConnection() throws JMSException
{
MQQueueConnectionFactory conFactory= new MQQueueConnectionFactory();
conFactory.setHostName(host);
conFactory.setPort(port);
conFactory.setTransportType(JMSC.MQJMS_TP_CLIENT_MQ_TCPIP);
conFactory.setQueueManager(qm);
conFactory.setChannel(channel);
qCon= (MQQueueConnection) conFactory.createQueueConnection();
MQQueueSession qSession=(MQQueueSession) qCon.createQueueSession(false, 1);
MQQueue queue=(MQQueue) qSession.createQueue(qn);
MQQueueBrowser browser = (MQQueueBrowser) qSession.createBrowser(queue);
qCon.start();
enumeration= browser.getEnumeration();
}
#Override
public StorageLevel storageLevel() {
return StorageLevel.MEMORY_ONLY_2();
}
}

Answer 2

I believe you can use JMS to connect to connect Websphere MQ, and Apache Camel can be used to connect to Websphere MQ. You can create a custom Receiver like so (note that this pattern could also be used without JMS):
class JMSReceiver(topicName: String, cf: String, jndiProviderURL: String)
extends Receiver[String](StorageLevel.MEMORY_AND_DISK_SER) with Serializable {
//Transient as this will get passed to the Workers from the Driver
#transient
var camelContextOption: Option[DefaultCamelContext] = None
def onStart() = {
camelContextOption = Some(new DefaultCamelContext())
val camelContext = camelContextOption.get
val env = new Properties()
env.setProperty("java.naming.factory.initial", "???")
env.setProperty("java.naming.provider.url", jndiProviderURL)
env.setProperty("com.webmethods.jms.clientIDSharing", "true")
val namingContext = new InitialContext(env); //using the properties file to create context
//Lookup Connection Factory
val connectionFactory = namingContext.lookup(cf).asInstanceOf[javax.jms.ConnectionFactory]
camelContext.addComponent("jms", JmsComponent.jmsComponentAutoAcknowledge(connectionFactory))
val builder = new RouteBuilder() {
def configure() = {
from(s"jms://topic:$topicName?jmsMessageType=Object&clientId=$clientId&durableSubscriptionName=${topicName}_SparkDurable&maxConcurrentConsumers=10")
.process(new Processor() {
def process(exchange: Exchange) = {
exchange.getIn.getBody match {
case s: String => store(s)
}
}
})
}
}
}
builders.foreach(camelContext.addRoutes)
camelContext.start()
}
def onStop() = if(camelContextOption.isDefined) camelContextOption.get.stop()
}
You can then create a DStream of your events like so:
val myDStream = ssc.receiverStream(new JMSReceiver("MyTopic", "MyContextFactory", "MyJNDI"))