Connection Handling

Connections to a message server are specified by a broker host name and port number.

• Set MQ_BROKER_NAME_PROPERTY to specify the broker name.

• Set MQ_BROKER_PORT_PROPERTY to specify the port of the broker's port mapper service. In this case, the port mapper will dynamically assign the port to which the client connects.

• Set MQ_BROKER_SERVICE_PORT_PROPERTY to specify the number of a port to which the client connects. This is a static, fixed port assignment; it bypasses the broker's port mapper service. If you do need to connect to a fixed port on the broker, make sure that the service needed is enabled and available at the specified port by setting the imq.serviceName.protocolType.port broker property.

• Set the connection property MQ_CONNECTION_TYPE_PROPERTY to specify the underlying transport protocol. Possible values are TCP or SSL.

  Remember that you need to configure the JMS service port on the broker side as well. For example, if you want to connect your client via ssljms to port 1756, you would do the following.

  • On the client side: Set the MQ_SERVICE_PORT_PROPERTY to 1756 and set the MQ_CONNECTION_TYPE_PROPERTY to SSL.

  • On the broker side: Set the imq.serviceNameType.protocol.port property to 1756 as follows.

    imq.ssljms.ssl.port=1756

The MQ_PING_INTERVAL_PROPERTY also affects connection handling. This property is set to the interval (in seconds) that the connection can be idle before the C client runtime pings the broker to test whether the connection is still alive. This property is useful for either producers who use the connection infrequently or for clients who are exclusive consumers, passively waiting for messages to arrive. The default value is 30 seconds. Setting an interval that is too low may result in some performance loss. The minimum permitted value is 1 second to prevent this from happening.

Currently, the C-API does not support auto-reconnect or failover, which allows the client runtime to automatically reconnect to a broker if a connection fails.