7.2

Table 4‑2. Workflow Subscription and Event Broker Terminology (Continued)
Term Description
Tenant Administrator The user with privileges to create, read, update, and delete
tenant workflow subscriptions for their tenant.
Workflow Subscription Specifies the event topic and conditions that trigger a
vRealize Orchestrator workflow.
System Workflow Subscription A specialized workflow subscription that reacts to system events
and to events in all the tenants.
Tenant Workflow Subscription A specialized workflow subscription that specifies which
conditions trigger a vRealize Orchestrator workflow for events in
the same tenant.
Blockable and Replyable Event Topics
Event topics might support blockable and replyable events. The behavior of a workflow subscription
depends on whether the topic supports these event types and how you configure the workflow
subscription.
Non-Blockable Event Topics
Non-blockable event topics only allow you to create non-blocking subscriptions. Non-blocking
subscriptions are triggered asynchronously and you can not rely on the order that the subscriptions are
triggered or that the vRealize Orchestrator workflows run. Non-blocking subscriptions only return a
response if the topic is replyable.
Blockable Event Topics
Some event topics support blocking. If a workflow subscription is marked as blocking, then all messages
that meet the configured conditions are not received by any other workflow subscriptions with matching
conditions until the first workflow is finished. If you have multiple blocking workflow subscriptions for the
same event topic, you prioritize the subscriptions.
Blocking subscriptions run in priority order. The highest priority value is 0 (zero). If you have more than
one blocking subscription for the same event topic with the same priority level, the subscriptions run in
alphabetical order based on the name. After all blocking subscriptions are processed, the message is
sent to all the nonblocking subscriptions at the same time. Because the blocking workflow subscriptions
run synchronously, the changed event payload includes the updated event when the subsequent workflow
subscriptions are notified.
You apply blocking to one or more workflow subscriptions depending on the selected workflow and your
goals.
For example, you have two provisioning workflow subscriptions where the second workflow depends on
the results of the first. The first one changes a property during provisioning, and a second records the
new property, perhaps a machine name, in a file system. The ChangeProperty subscription is prioritized
as 0 and the RecordProperty is prioritized as 1 because it uses the results of the ChangeProperty
Life Cycle Extensibility
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