MQSeries.net :: View topic - Excessive creation of short lived objects using client Mode

gcrooks · Posted: Tue Jan 30, 2007 4:47 am Post subject:

I have a Business Partner that has a java application that connections and uses the Java MQ API v6.0.
They are using this in client mode with the java client connecting using the MQ API to a remote queue on another server machine v6.0.
This is entire Linux environment.
They run their test application detailed below and then profile with netbeans they see a large number of objects being created by the MQAPI.
So much so that they see the GC being heavily utilised and impacts performance.

In Client Mode they are seeing 190 objects per message
In Binding mode they are seeing 30 objects per message

Can anybody tell me why this excessive creation of objects
Thanks

Below is info from the Business Partner
--Process -----------------------------------------------

1. Clear MQ message queue and run 'put_inbound_queue_1.sh'
2. Attach Netbeans 5.5 profiler to the simulator and take initial memory
snapshot (see attached screenshot)
3. Press enter to start putting messages (10,000)
4. Take final memory snapshot

Similar steps are followed for the profiling of 10,000 MQ GET operations

---Operation---
CLASSPATH=/export/opt/mqm/samp/java/base/bin:/opt/mqm/java/lib/com.ibm.mq.jar
MQM_HOST=app1.dev
MQM_CHANNEL=CHANNEL1
MQM_QMGR=distra.queue.manager
MQM_CONNECTIONS=1
MQM_QNAME=INBOUND.QUEUE.1
MSG_SIZE=20
MSG_COUNT=10000
MQM_COMMIT_BATCH=1
java -agentpath:/opt/netbeans-5.5/profiler1/lib/deployed/jdk15/linux/libprofilerinterface.so=/opt/netbeans-5.5/profiler1/lib,5140 -server -showversion -verbose:gc -Xloggc:gc.log -Xms1500m -Xmx1500m -XX:NewSize=100m -XX:MaxNewSize=100m -XX:SurvivorRatio=2 -XX:MaxTenuringThreshold=16 -XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled -XX:+UseParNewGC -XX:+DisableExplicitGC -XX:+PrintHeapAtGC -XX:+PrintGCTimeStamps -XX:+PrintGCDetails -XX:+PrintGCApplicationStoppedTime -XX:-OmitStackTraceInFastThrow -classpath $CLASSPATH OutboundSimNoReport $MQM_HOST $MQM_CHANNEL $MQM_QMGR $MQM_CONNECTIONS $MQM_QNAME $MSG_SIZE $MSG_COUNT $MQM_COMMIT_BATCH

import com.ibm.mq.MQC;
import com.ibm.mq.MQEnvironment;
import com.ibm.mq.MQException;
import com.ibm.mq.MQGetMessageOptions;
import com.ibm.mq.MQMessage;
import com.ibm.mq.MQQueue;
import com.ibm.mq.MQQueueManager;

public class InboundSim implements Runnable {

public static final int SHOW_SUMMARY_EVERY_XXX_NO_OF_MSGS = 250;

private static volatile boolean stopRunning;

private String instance;
private String qMgrName;
private String qName;
private int commitEveryXNoOfMsg;

public InboundSim(String instance,
String qMgrName,
String qName,
int commitEveryXNoOfMsg) {
this.instance = instance;
this.qMgrName = qMgrName;
this.qName = qName;
this.commitEveryXNoOfMsg = commitEveryXNoOfMsg;
}

public void run() {
try {
System.out.println(instance+":: Connecting to queue manager: "+qMgrName);
MQQueueManager qMgr = new MQQueueManager(qMgrName);

System.out.println(instance+":: Accessing inbound queue: "+qName);
MQQueue inbound = qMgr.accessQueue(qName, MQC.MQOO_INPUT_AS_Q_DEF);

MQGetMessageOptions gmo = new MQGetMessageOptions();
gmo.options = MQC.MQGMO_SYNCPOINT | MQC.MQGMO_WAIT;
gmo.waitInterval = 1000;

MQMessage msg = new MQMessage();
int i = 0;
int currentTotal = 0;
long start = System.currentTimeMillis();

System.out.println(instance+":: Committing every "+commitEveryXNoOfMsg+" msgs...");

while(!stopRunning) {
try {
msg.messageId = MQC.MQMI_NONE;
msg.correlationId = MQC.MQCI_NONE;
inbound.get(msg, gmo);
} catch (MQException ex) {
if (ex.reasonCode == MQException.MQRC_NO_MSG_AVAILABLE) {
continue;
} else {
throw ex;
}
}

if (i > 0 && (i % commitEveryXNoOfMsg) == 0) {
qMgr.commit();
}

i++;
currentTotal++;
if ((i % SHOW_SUMMARY_EVERY_XXX_NO_OF_MSGS) == 0) {
long end = System.currentTimeMillis();
long duration = end - start;
System.out.println(instance+":: ["+i+"]: current MPS: "+((int) (currentTotal/(duration/1000.0))));
start = end;
currentTotal = 0;
}
}

// Close the queue
System.out.println(instance+":: Closing the queue");
inbound.close();

// Disconnect from the QueueManager
System.out.println(instance+":: Disconnecting from the Queue Manager");
qMgr.disconnect();
System.out.println(instance+":: Done!");
} catch (MQException ex) {
System.out.println("A WebSphere MQ Error occured : Completion Code " +
ex.completionCode + " Reason Code " + ex.reasonCode);
}
}

public static void main(String args[]) throws Exception {
// Command line args
String hostname = args[0];
String channel = args[1];
String qMgrName = args[2];
final int noOfConnections = Integer.parseInt(args[3]);
String qName = args[4];
int commitEveryXNoOfMsg = Integer.parseInt(args[5]);

System.out.println("Press [Enter] to start.");
try {
System.in.read();
} catch (Exception ignore) {}

MQEnvironment.hostname = hostname;
MQEnvironment.port = -1;
MQEnvironment.channel = channel;
System.out.println("Connecting to host: "+hostname);
System.out.println("Connecting to channel: "+channel);

System.out.println("Start "+noOfConnections+" simultaneous connection(s)");

final Thread[] threads = new Thread[noOfConnections];

for (int i=0; i<noOfConnections; i++) {
InboundSim is = new InboundSim("Connection #"+(i+1),
qMgrName,
qName,
commitEveryXNoOfMsg);
threads[i] = new Thread(is);
threads[i].start();
}

Runtime.getRuntime().addShutdownHook(new Thread() {
public void run() {
stopRunning = true;
for (int i=0; i<noOfConnections; i++) {
try {
threads[i].join();
} catch (Exception ignore) {}
}
}
});
}
}