Cannot connect to WebSphere MQ for Sterling B2B Integrator events

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A Global Mailbox node in a particular data center is unable to connect to WebSphere® MQ for Sterling B2B Integrator events.

Symptoms

An event, with the error code, GMWMQ0001E, is generated in the messages.log file at the time of the failure.

If your system is configured for monitoring by IBM® Control Center, a notification with the error code, GMWMQ0001E, is sent to IBM Control Center at the time of the failure. You can view the details of the event in the IBM Control Center user interface. If you configured the appropriate rule and action in IBM Control Center, you might receive an email notification at the time of the failure.

The error code, GMWMQ0001E, has the following message: 
Cannot connect to Websphere MQ
GMWMQ0001E is also delivered with the following details:
nodeId
Originating data center and node that attempted to WebSphere MQ in the format gm/data center name/hostname. If the notification originated from Sterling B2B Integrator, the format is gm/data center name/gmca/hostname
application
The application from which the events on the queue originated
service
The service ID associated with the queue in the data center in the format mq/<application name>
reason
Exception string from the queue
connectionList
The list of queue connections in the format host:port, host2:port2, and so forth
queueMgr
The name of the queue manager
queue
The name of the queue
channel
The name of the channel
userId
The ID of the user that connected to queue at the time of the reconnection
status
The status of the server, DOWN

Causes

Global Mailbox might be unable to access WebSphere MQ for the following reasons:

WebSphere MQ down
The WebSphere MQ component might be down.
Network problem
There is a network partition between the Global Mailbox instance and the WebSphere MQ component.
Incorrect configuration
The WebSphere MQ component might be incorrectly configured.

Environment

Windows, UNIX, or Linux®.

Diagnosing the problem

To confirm which node was unable to access WebSphere MQ, view the details of the event with the error code, GMWMQ0001E, at the time of the failure. Determine the data center and node (or nodes) unable to access the queue with nodeId.

Resolving the problem

In an installation where WebSphere MQ is connected between data centers, determine whether only some nodes are unable to access WebSphere MQ. If only some nodes are unable to access the message queue, there might be a network partition between the nodes and the queue. A network partition indicates that packets are not being correctly transmitted within the data center. There might be a network connection issue within your system.

In an installation where WebSphere MQ is connected to nodes within a data center, determine whether all nodes in that data center are unable to access WebSphere MQ. If all nodes are unable to access the message queue, there might be a network partition within your data center, or WebSphere MQ is down.

In the case that the message queue is down, ensure that WebSphere MQ is correctly configured. For more information about configuring WebSphere MQ, see Installing highly available WebSphere MQ for event processing.

When the problem is successfully resolved, a new event with the code, GMWMQ0001I, is generated in the messages.log file, or a notification with the code, GMWMQ0001I, is received from IBM Control Center with the following message: 
Successfully connected to Websphere MQ
The message is delivered with the following details:
status
The status of the server, UP
nodeId
Originating data center and node that successfully connected to WebSphere MQ in the format gm/data center name/hostname. If the notification originated from Sterling B2B Integrator, the format is gm/data center name/gmca/hostname
application
The application from which the events on the queue originated
service
The service ID associated with the queue in the data center in the format mq/<application name>
connectionList
The list of queue connections in the format host:port, host2:port2, and so forth
queueMgr
The name of the queue manager
queue
The name of the queue
channel
The name of the channel
userId
The ID of the user that connected to queue at the time of the reconnection
preceedingFailureCount
The total number of times a node in the system is unable to reach WebSphere MQ