Subscribing to event message topics
You can subscribe to topics that return messages about the configuration, state, or operational status of your integration node, integration server, or message flows.
About this task
A subscriber can send a subscription request to the pub/sub broker that specifies the event messages that the subscriber wants to receive. To receive IBM® Integration Bus event messages, use the following information to define the subscription requests.
- For an MQTT pub/sub broker, the topic root is
IBM/IntegrationBus
. For example,IBM/IntegrationBus/integrationNodeName/Status/ExecutionGroup/integrationServerName
- For an MQ pub/sub broker, the topic root is
$SYS/Broker
. For example,$SYS/Broker/integrationNodeName/Status/ExecutionGroup/integrationServerName
topicRoot/+/StatisticsAccounting/#
where topicRoot is IBM/IntegrationBus
for
an MQTT pub/sub broker and $SYS/Broker
for an MQ
pub/sub broker. For more information about how you can use wildcards,
see Special characters in topics.You can subscribe to IBM Integration Bus messages in the following categories:
- Message flow performance
- If you enable message flow accounting and statistics collection
for an integration node, the integration node publishes messages (JSON
or XML publications) at an interval that you can control by setting
the statsInterval property of the integration node.
You can subscribe to these messages on the following topics:
- For JSON publications:
topicRoot/integrationNodeName/Statistics/JSON/recordType/integrationServerName/messageFlowName
- For XML publications:
topicRoot/integrationNodeName/StatisticsAccounting/recordType/integrationServerName/messageFlowName
Note: For an MQ pub/sub broker, each message is a JMS TextMessage that contains the statistics report in XML format. If you want the message in a JMS BytesMessage format, use one of the following methods:- Set the environment variable MQSI_STATS_MQSTR=false.
- Run the mqsichangeproperties command
with the pubsub component to change the format. For example:
The pubsub component change overrides the use of environment variables. For more information, see Parameter values for the pubsub component.mqsichangeproperties IBNODE -b pubsub -o OperationalEvents/MQ -n format -v none
- For JSON publications:
- Resource performance
- If you enable resource statistics collection for one or more integration
servers on an integration node, the integration node publishes messages
(JSON or XML publications) at 20-second intervals. You can subscribe
to these messages on the following topics:
- For JSON publications:
topicRoot/integrationNodeName/Statistics/JSON/Resource/integrationServerName
- For XML publications:
topicRoot/integrationNodeName/ResourceStatistics/integrationServerName
Note: For an MQ pub/sub broker, each message is a JMS TextMessage that contains the resource statistics report in XML format. If you want the message in a JMS BytesMessage format, use one of the following methods:- Set the environment variable MQSI_STATS_MQSTR=false.
- Run the mqsichangeproperties command with the pubsub component to change the format.
For more information about how to interpret the resource statistics that are included in the publication, see Viewing resource statistics data.
- For JSON publications:
- Configuration changes
- The integration node publishes messages (XML publications) when
an entity is created, changed, or deleted on an integration server.
You can subscribe to these messages on the following topic:
topicRoot/integrationNodeName/Configuration/ExecutionGroup/integrationServerName
For an example message, see Example: changes to the local configuration of the integration node.
- State changes
- The integration node publishes messages (XML publications) when
an integration node, integration server, or message flow stops or
starts. You can subscribe to these messages on the following topics:
- State changes associated with an integration node:
topicRoot/integrationNodeName/Status
- State changes associated with an integration server (including
state changes to resources that are deployed to an integration server):
topicRoot/integrationNodeName/Status/ExecutionGroup/integrationServerName
For an example message, see Example: changes to state of an integration node or message flow.
- State changes associated with an integration node:
- Workload management
-
The message rate statistics are collected at a checkpoint that occurs every 20 seconds. The total message rate is calculated at this checkpoint, and if the total message rate exceeds the notification threshold, the out of range XML message is published. If the total message rate continues to stay above the notification threshold, then no further out of range messages are published.
If you enable the notification threshold, you can subscribe to the following topics:- Message flow is in a library within an application:
topicRoot/integrationNodeName/WorkloadManagement/AboveThreshold/integrationServerName/applicationName/libraryName/messageFlowName
- Message flow is in a library that is not within an application:
topicRoot/integrationNodeName/WorkloadManagement/AboveThreshold/integrationServerName/libraryName/messageFlowName
- Message flow is directly in an application (not in a library within
the application):
topicRoot/integrationNodeName/WorkloadManagement/AboveThreshold/integrationServerName/applicationName/messageFlowName
- Message flow is not in an application or a library:
topicRoot/integrationNodeName/WorkloadManagement/AboveThreshold/integrationServerName/messageFlowName
- Message flow is in a library within an application:
- Monitoring
- You can configure your message flow to emit event messages that
can be used to support transaction monitoring and auditing, and business
process monitoring; see Configuring monitoring for message flows. To receive
event messages from your message flows, subscribe to the following
topic:
topicRoot/Monitoring/integrationServerName/messageFlowName
Note: When you use the built-in MQTT pub/sub broker, Monitoring events are not published by default. You must enable the publication of Monitoring events to the built-in MQTT pub/sub broker.
Results
Subscribers receive statistics reports only from those integration nodes that are enabled to produce statistics.