Network Deployment (Distributed operating systems), v8.0 > Reference > Developer best practices
Migration of message fields
When you use the WAS message migration utility to migrate a message from JMS format to service integration format, most fields are migrated unchanged. However, some fields are changed and some are not supported by service integration.
Changes to messages due to migration
All JMS message types migrate unchanged:
- Message
- TextMessage
- MapMessage
- StreamMessage
- ObjectMessage
- BytesMessage
User properties set on the message by an application are also unaltered.
The JMS message types provide header fields that can change as a result of migration:
JMS Message Header fields. The first column of the table contains the list of the header field names. The second column indicates if the fields of the messages are migrated without any changes.
Header field name State after migration JMSMessageID Unchanged JMSCorrelationID Unchanged JMSDeliveryMode Unchanged JMSPriority Unchanged JMSTimestamp Unchanged JMSExpiration Unchanged JMSRedelivered Can be reset as a result of the migration process. JMSType Unchanged JMSDestination The name of the destination is unaltered. Other properties of the destination are mapped to their equivalents in the later version, where possible. JMSReplyTo The name of the reply destination is unaltered, and assumed to exist on the bus to which the messages are being migrated.
- References to temporary queues or topics are migrated in the same way as for permanent reply destinations. It will not be possible to send reply messages to these destinations because they will not exist in the bus.
- Topic reply-to destinations are assumed to be topics within the default topic space, which must exist for the reply message to be sent.
JMSX properties can also change as a result of migration.
JMSX properties. The first column of the table contains the list of the JMSX property names. The second column indicates if the properties have changed or not supported by the service integration bus after the migration.
JMSX property name State after migration JMSXUserID Unchanged JMSXAppID Unchanged JMSXDeliveryCount Can be reset as a result of the migration process. JMSXGroupID Unchanged JMSXGroupSeq Unchanged JMSXProducerTXID Not supported by service integration bus. JMSXConsumerTXID Not supported by service integration bus. JMSXRcvTimestamp Not supported by service integration bus. JMSXState Not supported by service integration bus. The following JMS_IBM properties do not change as a result of migration.
JMS_IBM properties. The first column of the table contains the list of the JMS_IBM property names. The second column indicates the state of the properties after the migration. The JMS_IBM properties do not change after migration.
JMS_IBM property name State after migration JMS_IBM_Report_* Unchanged JMS_IBM_MsgType Unchanged JMS_IBM_Feedback Unchanged JMS_IBM_Format Unchanged JMS_IBM_PutApplType Unchanged JMS_IBM_Encoding Unchanged JMS_IBM_Character_Set Unchanged JMS_IBM_PutDate Unchanged JMS_IBM_PutTime Unchanged JMS_IBM_Last_Msg_In_Group Unchanged