Messaging engines [Collection]

Messaging engines [Collection]

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.

To browse or change the properties of a listed item, select its name in the list.

To act on one or more of the listed items, select the check boxes next to the names of the items to act on, then use the buttons provided.

To change which entries are listed, or to change the level of detail displayed for those entries, use the Filter settings.

Name

The name of the messaging engine.

Description

An optional description for the messaging engine, for administrative purposes.

Status

The current status of the messaging engine. Status settings are started or stopped.

Buttons

Button Description
Enable policy assistance This button only applies to messaging engines in a clustered environment.
Start the wizard that provides messaging engine policy assistance, that is, guidance about creating one or more messaging engines for the cluster and configuring the messaging engine behavior. This button is available only when messaging engine policy assistance is not enabled already.

Add messaging engine This button only applies to messaging engines in a clustered environment.
Add a new messaging engine to the server cluster.

Remove messaging engine This button only applies to messaging engines in a clustered environment.
Remove the selected messaging engines from the server cluster.

Start Start selected items.
Stop Stop the selected messaging engines. We must first select the messaging engines to be stopped. We can select a Stop mode:

Immediate

The messaging engine stops after all messaging operations that are occurring at the time of the stop request have completed. After a stop request is issued, no new messaging operations can start.
For each existing connection, the messaging engine waits for the current operation to complete, unless the operation is one that blocks processing in the messaging engine, such as a receive operation. In this case, the operation is interrupted. Asynchronous consumers can complete, even though they might take an arbitrary amount of time to process the current message. The messaging engine then backs out of active transactions and disallows any further operations on that connection. When all connections are in this invalidated state, the messaging engine stops.

Force

The messaging engine stops without allowing messaging operations to complete. Applications are forcefully disconnected.
This mode completes the shutdown of the messaging engine in as short a time as possible. When a messaging engine that was stopped using force mode is restarted, the restart might take longer than if it was stopped using immediate mode, because more recovery actions are needed. For example, messages might be left in an indoubt state and we must deal with these messages to resolve any indoubt transactions.

Tip: If an immediate stop takes too long, we can select the Force option to escalate it to a force stop. This overrides the previous selection of the Immediate option.

Button	Description
Enable policy assistance	This button only applies to messaging engines in a clustered environment. Start the wizard that provides messaging engine policy assistance, that is, guidance about creating one or more messaging engines for the cluster and configuring the messaging engine behavior. This button is available only when messaging engine policy assistance is not enabled already.
Add messaging engine	This button only applies to messaging engines in a clustered environment. Add a new messaging engine to the server cluster.
Remove messaging engine	This button only applies to messaging engines in a clustered environment. Remove the selected messaging engines from the server cluster.
Start	Start selected items.
Stop	Stop the selected messaging engines. We must first select the messaging engines to be stopped. We can select a Stop mode: Immediate The messaging engine stops after all messaging operations that are occurring at the time of the stop request have completed. After a stop request is issued, no new messaging operations can start. For each existing connection, the messaging engine waits for the current operation to complete, unless the operation is one that blocks processing in the messaging engine, such as a receive operation. In this case, the operation is interrupted. Asynchronous consumers can complete, even though they might take an arbitrary amount of time to process the current message. The messaging engine then backs out of active transactions and disallows any further operations on that connection. When all connections are in this invalidated state, the messaging engine stops. Force The messaging engine stops without allowing messaging operations to complete. Applications are forcefully disconnected. This mode completes the shutdown of the messaging engine in as short a time as possible. When a messaging engine that was stopped using force mode is restarted, the restart might take longer than if it was stopped using immediate mode, because more recovery actions are needed. For example, messages might be left in an indoubt state and we must deal with these messages to resolve any indoubt transactions. Tip: If an immediate stop takes too long, we can select the Force option to escalate it to a force stop. This overrides the previous selection of the Immediate option.