Event message architecture

Integration servers publish messages on reserved topics after significant events within the integration server. By subscribing to these topics, a client is informed when these events occur.

For each topic, the type of event and message body are explained. The body of these messages is either in JSON or XML format, depending on the topic.

An event publication can contain more than one entry if the topic is the same.

The general notation of the system topics on which events are published is as follows:

$SYS/Broker/integrationNodeName/event_type/integrationServerName
/applications/application_name/libraries/library_name/messageflows/message_flow_name

For an integration server that is managed by an integration node, integrationNodeName is the name of the integration node that manages the integration server. For an independent integration server, specify the literal string integration_server in place of an integration node name.

For example:

For an integration server that is managed by an integration node:

$SYS/Broker/myIntegrationNode1/Statistics/JSON/SnapShot/myIntegrationServer3/applications/myApplicationA
/libraries/myLibraryD/messageflows/myMessageFlow6

For an independent integration server:

$SYS/Broker/integration_server/Statistics/JSON/SnapShot/myIntegrationServer3/applications/myApplicationA
/libraries/myLibraryD/messageflows/myMessageFlow6

For events that are published by using MQTT as the transport, the notation is as follows:

IBM/IntegrationBus/integrationNodeName/event_type/integrationServerName
/applications/application_name/libraries/library_name/messageflows/message_flow_name

integrationNodeName

The name of the integration node that issues or raises this event, or, in the case of an independent integration server, the literal string integration_server.

event_type

event_type is the type of the event. The possible event types are shown in the following table:

Table 1. Types of event and how they are represented in publication topics. The table describes the event groups, event types, and the equivalent notation for `event_type`.
Event group	Event type	Notation format for `event_type`
OperationalEvents	Resource statistics (JSON) Resource statistics (XML) Message flow statistics (JSON) Message flow statistics (XML) Workload Management	`Statistics/JSON/Resource` `ResourceStatistics` `Statistics/JSON` `StatisticsAccounting` `WorkloadManagement`
BusinessEvents	Monitoring	Monitoring
AdminEvents	Admin log (JSON)	AdminLog/JSON

Message flow statistics and resource statistics event types are published in both JSON and XML format. Admin events are published in JSON format. All other event types are published in XML format. For more information, see Output formats for message flow accounting and statistics data.

When you subscribe to events, the topic structure enables you to filter the events by integration node, integration server, and type of event. For specific events, additional information is included in the topic to help filter on the specific object that raised the event. The inclusion of the string Broker (or for MQTT, IntegrationBus) at the second level of the topic hierarchy allows for future extension to additional subsystems that publish system management events through the integration node or server. For more information, see Subscribing to event message topics.