Messaging engines [Settings]
A messaging engine is a component, running inside a server, that manages messaging resources for a bus member. Applications are connected to a messaging engine when they access a service integration bus.
To view this page in the console, click the following path:
Service integration -> Buses -> bus_name -> [Topology] Messaging engines -> engine_name.
Configuration tab
The Configuration tab shows configuration properties for this object. These property values are preserved even if the runtime environment is stopped then restarted. See the information center task descriptions for information about how to apply configuration changes to the runtime environment.
General Properties
Name
The name of the messaging engine.
| Information | Value |
|---|---|
| Required | No |
| Data type | String |
UUID
The universal unique identifier assigned by the system to this messaging engine for administrative purposes.
| Information | Value |
|---|---|
| Required | No |
| Data type | String |
Description
An optional description for the messaging engine, for administrative purposes.
| Information | Value |
|---|---|
| Required | No |
| Data type | Text area |
Initial state
The initial state determines whether the messaging engine is started automatically.
If this property is selected, the messaging engine starts automatically when its associated application server is started. Until the messaging engine starts, it is unavailable.
| Information | Value |
|---|---|
| Required | No |
| Data type | drop-down list |
| Range |
|
Message store type
The type of message store used. Either file store or data store. Once the messaging engine has been created this cannot be changed, only configured.
| Information | Value |
|---|---|
| Required | No |
| Data type | drop-down list |
| Range |
|
High message threshold per message point
The number of messages queued on a message point on this messaging engine, at which point new messages are not accepted on the message point. However, certain messages that are already in the bus and that are being transmitted to this messaging engine might be accepted.
When the messaging engine is created, the high message threshold of the bus is used to set the default value for this property. When a message point is created on this messaging engine, the value of this property is used to set the default high message threshold for the message point.
| Information | Value |
|---|---|
| Required | No |
| Data type | Integer |
| Range | 1 through 9223372036854775807
There are implications for the Java Virtual Machine (JVM) heap size when using a high message threshold, if large numbers of messages are held on a queue (each message consumes approximately 200 bytes of storage). Therefore if you increase the high message threshold because you are expecting large numbers of messages on the queues, you should also modify the JVM heap size of the server as appropriate. |
Default blocked destination retry interval
The time delay, in milliseconds, that is introduced by the system under certain circumstances before a failed message delivery to an application will be retried. This delay can be overridden by individual Queue destination configurations.
When you configure a bus destination, we can specify an associated exception destination and a maximum number of times that an individual message fails to be consumed before it is put on that exception destination. Alternatively, if we do not specify an associated exception destination, the system continues to try to deliver the message. In this situation, the system attempts to deliver the message, without applying any delay, until it reaches the maximum failed deliveries limit set for the bus destination (a queue or a topic space). After the maximum failed deliveries limit is reached, the default blocked destination retry interval is applied before the message is retried.
The Default blocked destination retry interval specifies the time interval between retry attempts, which will be used by all queue and topic destinations associated with this messaging engine. We can override this default value when you configure an individual queue or topic destination.
| Information | Value |
|---|---|
| Required | No |
| Data type | Integer (milliseconds) |
| Default | The value taken from the sib.processor.blockedRetryTimeout custom property, if set. Otherwise it is set to 5000. |
| Range | 1 through 9223372036854775807
|
Target groups
A list of names of target groups with which the messaging engine will register.
Custom target groups are a type of target group used by JMS connection factories. When an application creates a connection to a service integration bus, it uses connection factory properties to specify suitable messaging engines to connect to. When a target type of "Custom" is specified in the connection factory targetType property, the application is connected to one of the messaging engines in the specified custom target group. A particular messaging engine is selected from the group according to the other connection factory properties specified.
| Information | Value |
|---|---|
| Required | No |
| Data type | Text area |
Bus name
The name of the service integration bus on which the messaging engine is configured.
| Information | Value |
|---|---|
| Required | No |
| Data type | String |
Bus UUID
The universal unique identifier of the service integration bus on which the messaging engine is configured.
| Information | Value |
|---|---|
| Required | No |
| Data type | String |
Message points
- Mediation points
- A mediation point is created on each messaging engine to which the mediation of a mediated destination is assigned. It is used to hold messages pending delivery to the mediation.
- Queue points
- A queue point is created on each messaging engine to which a point-to-point destination is assigned. It is used to hold messages pending delivery to receiving applications.
- Publication points
- A publication point is created on each messaging engine in the bus when a publish/subscribe destination is created. The publication point on a messaging engine is used to hold messages published by applications connected to that messaging engine until they are delivered to subscribers.
Additional Properties
- Mediation execution points
- Mediation execution points for the processing of messages from mediation message points that are on a WebSphere MQ server.
- Service integration bus links
- A communications link between this messaging engine and a messaging engine in a foreign service integration bus.
- Mediation thread pool
- The thread pool for allocating mediation handler threads.
- Message store
- The properties for the message store in use by this messaging engine as determined by the message store type field. The message store can be either a file store or a data store.
- WebSphere MQ client links
- A WebSphere MQ client link enables JMS client applications to connect, via this messaging engine, to the service integration bus, as though it were a WebSphere MQ queue manager.
- WebSphere MQ links
- Links between the messaging engine and WebSphere MQ networks. Each WebSphere MQ link connects the messaging engine as a queue manager to WebSphere MQ, providing a bridge between the bus and a WebSphere MQ network.
- Custom properties
- Arbitrary name-value pairs of data, where the name is a property key and the value is a string value that can be used to set internal system configuration properties. Defining a new property enables you to configure a setting beyond that which is available in the administrative console.
- Reliable messaging state
- Use this page to view and manage the WS-ReliableMessaging runtime state.
Related Items
- Bus member
- The bus member associated with this messaging engine.
Runtime tab
The Runtime tab shows runtime properties for this object. These properties directly affect the current runtime environment, but are not preserved when that environment is stopped. To preserve runtime property values, change the equivalent property values on the Configuration tab. See the information center task descriptions for information about how to apply configuration changes to the runtime environment.
General Properties
Status
The current status of the messaging engine. Status settings are started or stopped.
To be able to retrieve the status of messaging engines, you must be logged into the administrative console with at least monitor authority. If we do not have this authority, the messaging engine status is displayed as "Unavailable", even if the messaging engine has started.
| Information | Value |
|---|---|
| Required | No |
| Data type | String |
Message points
- Queue points
- A queue point is created on each messaging engine to which a point-to-point destination is assigned. It is used to hold messages pending delivery to receiving applications.
- Publication points
- A publication point is created on each messaging engine in the bus when a publish/subscribe destination is created. The publication point on a messaging engine is used to hold messages published by applications connected to that messaging engine until they are delivered to subscribers.
- Mediation points
- A mediation point is created on each messaging engine to which the mediation of a mediated destination is assigned. It is used to hold messages pending delivery to the mediation.
Remote message points
- Remote queue points
- The remote queue points that are producing/consuming messages to/from queue points on remote messaging engines.
- Remote mediation points
- The remote mediation points that are producing messages for mediation points on remote messaging engines.
- Remote publication points
- The remote publication points that are producing messages for publication points on remote messaging engines.
Related tasks
Related information:
Reference topic