When converting messages between WebSphere® MQ format and service integration format, service integration processes the message header fields and properties relating to message delivery mode, reliability, and persistence.
The WebSphere MQ format message contains the following indications of the quality of service:
This property is present in all WebSphere MQ format messages. The property specifies the quality of service that WebSphere MQ provides for the message as follows:
MQMD persistence | Quality of service |
---|---|
MQPER_PERSISTENT | Persistent quality of service. WebSphere MQ assures once and once only delivery of the message. |
MQPER_NOT_PERSISTENT | Nonpersistent quality of service. WebSphere MQ can discard the message in exceptional circumstances. |
MQPER_PERSISTENCE_AS_Q_DEF | WebSphere MQ sets the quality of service (persistent or nonpersistent) to the value configured for the destination queue. |
For more information about the WebSphere MQ persistent and nonpersistent qualities of service, see the WebSphere MQ documentation .
This property is present in WebSphere MQ format JMS messages that include the MQRFH2 header. The property contains the JMSDeliveryMode that was set when the application issued send for the message.
Message reliability levels - JMS delivery mode and service integration quality of service describes how service integration sets the message reliability. Briefly: JMS applications send messages with a JMS delivery mode (persistent or nonpersistent), then service integration uses JMS connection factory settings to map the JMS delivery mode to a service integration message reliability setting, and finally additional settings on bus destinations (including foreign destinations and alias destinations) can override this message reliability. When service integration converts the message to WebSphere MQ format, it sets the MQMD persistence indicator as follows:
Service integration message reliability | MQMD persistence |
---|---|
Reliable persistent | Persistent |
Assured persistent | Persistent |
Reliable nonpersistent | Nonpersistent |
Express nonpersistent | Nonpersistent |
Best effort nonpersistent | Nonpersistent |
The sending application can optionally override this by setting the JMS_IBM_MQMD_Persistence message property in the message.
When service integration receives a message from WebSphere MQ, it uses the MQMD persistence value of the message together with the corresponding service integration reliability value that you configure in the WebSphere MQ link receiver or the WebSphere MQ server queue point to determine the reliability of the service integration message.