Configuring bus properties

You can configure how many messages the bus can handle, when to discard messages, and which messaging engines the bus can communicate with. You can also specify changes that can be made to the bus that do not require a restart of the messaging engines.

1. Click Service integration -> Buses -> bus_name.
2. Specify the following properties for the bus:

   Description

   A service integration bus supports applications using message-based and service-oriented architectures. A bus is a group of interconnected servers and clusters that have been added as members of the bus. Applications connect to a bus at one of the messaging engines associated with its bus members.

   Inter-engine transport chain

   The transport chain used for communication between messaging engines in this bus.

   The transport chain must correspond to one of the transport chains defined in the Messaging engine inbound transports settings for the server. All servers automatically have a number of transport chains defined to them, and it is also possible to create new transport chains.

   When you specify the name of a transport chain, that chain must be defined to all servers hosting messaging engines in the bus. Otherwise, some messaging engines might not be able to communicate with their peers in the bus.

   When the use of permitted chains is enforced and a protocol is not specified for intra-bus communications then InboundSecureMessaging is assumed instead of InboundBasicMessaging. This can be overridden by setting the protocol attribute in the bus configuration. If InboundSecureMessaging is not a permitted chain then an error occurs.

   Discard messages

   Whether messages on a deleted message point should be retained at a system exception destination or can be discarded. Select this option to indicate that after a queue has been deleted, any messages remaining in the data store for that queue should be discarded.

   Configuration reload enabled

   Select this option to enable automatic update of configuration information on all the messaging engines on the bus.

   Changes to bus destinations or mediations are applied when destinations or mediations are added to or removed from the bus.

   Changes to the modifiable configuration information for any foreign bus connections are also updated automatically. The time when these changes take effect varies:

   Foreign Bus Connection properties

   Immediately

   WebSphere® MQ link properties

   On channel restart, except Description (immediately), and Initial State (on messaging engine restart)

   MQ sender channel properties

   On channel restart, except Initial State (on messaging engine restart or sender channel creation)

   MQ receiver channel properties

   On channel restart, except Initial State (on messaging engine restart or receiver channel creation)

   Publish/subscribe broker profile (0 to n) properties

   Immediately

   Service integration bus link properties

   On link restart, except Description (immediately), and Initial State (on messaging engine restart or link creation)

   To ensure that dynamic configuration updates are made on an application server, click Servers -> Server Types -> WebSphere application servers -> server_name -> [Server messaging] SIB service then select Configuration reload enabled.

   To ensure that dynamic configuration updates are made to each node, click System administration -> Console Preferences to display the Console Preferences window then select Synchronize changes with nodes.

   Default messaging engine high message threshold

   A threshold above which the messaging system will take action to limit the addition of more messages to a message point. When a messaging engine is created on the bus, the value of this property is used to set the default high message threshold for the messaging engine.

3. Specify topology, destination resources, web services and additional properties for the bus, as required.
   To restrict the number of audit messages, add a custom property called audit.bus.authentication with one of the following values:

   • all (audit all attempts to authenticate to the bus)
   • failure (audit only failure to authenticate to the bus)
   • none (do not audit any attempts to authenticate to the bus)
4. Optional: Add the sib.processor.PubSubProtocolWindowEnabled custom property to control the message flow between messaging engines in the publish/subscribe environments, where large number of messages flow across messaging engines. If the property value is set to true, the source messaging engine controls the message flow while sending messages to the target messaging engine. The source messaging engine evaluates the health of the target messaging engine by monitoring the ACKNOWLEDGEMENTs (ACKs) that are received for the already sent messages. Based on the ACK messages that are received, to avoid huge piling up of messages, the source messaging engine either continues to send the destined messages or temporarily stops sending messages until sufficient ACK messages are received.
5. Click OK.
6. Save your changes to the master configuration.