Frequently Asked Questions - Connecting to MQ on IBM Order Management on Cloud using different clients

1. Can Managed XMS .NET be used as a publisher and subscriber to MQ in OMoC?
We have seen issues with use of Managed XMS .NET in this regard -
Using XMS .NET to connect to MQ resulted in TCP connections being dropped after 4-5 minutes of connections.

XMS .NET being as a publisher-
The parameter HBINT was changed from 300 seconds to 60 seconds. Read more about this parameter at -https://www.ibm.com/docs/en/ibm-mq/9.2?topic=order-heartbeat-interval-hbint
With this change, connection drops were alleviated.

 XMS .NET being used as a subscriber-
Subscriber was not going stale in minutes, however ran for close to 55 hours before connections went stale.
To help counter above, the suggestion was to flush out the subscriber every 12 hours or so.

Recommendation - It is recommended using websphere mq .net client to connect to OMoC MQ since this provides a much better exception handling, overcoming the above listed issues

Also note - passing  OutboundSNI=HOSTNAME in the SSL stanza of the mqclient.ini file is not supported Managed XMS .NET-https://www.ibm.com/docs/en/ibm-mq/9.2?topic=file-which-mq-clients-can-read-each-attribute

2.  Can C or .NET(Unmanaged) be used for connections to MQ in OMoC?
If the third-party client or tool is C or .NET(Unmanaged), pass OutboundSNI=HOSTNAME in the SSL stanza of the mqclient.ini file. This attribute can be read by C, unmanaged .NET, IBM MQ classes for Java, and IBM MQ classes for Java, and IBM MQ classes for JMS clients only.

3. How can Kafka adapter from Confluent platform (using Oracle JDK) be used to connect to MQ in OMoC?
Here are configurations to help make a successful initial connection from Kafka adapter to MQ.
Config settings included -
The cipher suite selected for Oracle JDK - TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 with
2.   JVM option: -Dcom.ibm.mq.cfg.useIBMCipherMappings=false
3.  To set up the JVM option, pass an environment variable before starting kafka connect service -
export EXTRA_ARGS="-Dcom.ibm.mq.cfg.useIBMCipherMappings=false"
Here’s an example Confluent MQ connect configuration:
{
 "name": "IbmMQSourceConnectorConnector_Test",
 "config": {
   "connector.class": "io.confluent.connect.ibm.mq.IbmMQSourceConnector",
   "mq.hostname": "test-dev-1-mq.oms.supply-chain.ibm.com",
   "mq.port": "15443",
   "mq.queue.manager": "OM_QMGR",
   "mq.channel": "SYSTEM.TLS.SVRCONN",
   "mq.tls.keystore.location": "<path to keystore.jks file>",
   "mq.tls.keystore.password": "<keystore password>",
   "mq.tls.truststore.location": "<pass to truststore.jks file>",
   "mq.tls.truststore.password": "<trustore password>",
   "jms.destination.name": "YOUR_MQ_TOPIC_NAME",
   "jms.destination.type": "QUEUE",
   "kafka.topic": "your-kafka-topic-name",
   "mq.ssl.cipher.suite": "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384"
 }
}

The stability and performance of the connections from Kafka adapter to OMoC MQ have not been tested