Orchestrator is running multiple workflows and should only trigger a single instance

Products

• VCF Operations/Automation (formerly VMware Aria Suite)

Issue/Introduction

1. When a workflow in Aria Orchestrator is triggered by an Assembler event subscription (e.g., compute.provision.post), two instances of the workflow are executed simultaneously instead of the expected single instance. This can lead to inconsistent results, such as one instance completing successfully while the other fails or is canceled.

   Log entries in /services-logs/prelude/vco-app/file-logs/vco-server-app.log will show two separate workflow 'started' events with different execution IDs for the same workflow. These events often occur on different Orchestrator pods at nearly the exact same time.

   Example log of the first instance (canceled):

   <FQDN>/services-logs/prelude/vco-app/file-logs/vco-server-app.log:558:2025-10-30T15:26:55.064Z INFO vco [host='<vco pod a>' thread='WorkflowExecutorPool-Thread-43' user='<user>' org='<org id>' trace='-'] {} ch.dunes.workflow.engine.mbean.helper.WorkflowHandler - ************* Workflow '<workflow>' (id: <workflow id>) started. Execution id: <token> *************
   <FQDN>/services-logs/prelude/vco-app/file-logs/vco-server-app.log:708:2025-10-30T15:27:33.015Z INFO vco [host='<vco pod a>' thread='WorkflowExecutorPool-Thread-43' user='<user>' org='<org id>' trace='-'] {|__SYSTEM|<user>:<workflow>:<workflow id>:token=<token> ch.dunes.workflow.engine.mbean.helper.WorkflowHandler - ******** Workflow '<workflow>' (id: <workflow id>) has finished with status [ canceled ]. Execution id: <token> **********
   

   Example log of the second instance (completed):

   <FQDN>/services-logs/prelude/vco-app/file-logs/vco-server-app.log:839:2025-10-30T15:26:55.095Z INFO vco [host='<vco pod b>' thread='WorkflowExecutorPool-Thread-14' user='<user>' org='<org id>' trace='-'] {} ch.dunes.workflow.engine.mbean.helper.WorkflowHandler - ************* Workflow '<workflow>' (id: <workflow id>) started. Execution id: <another token>2 *************
   <FQDN>/services-logs/prelude/vco-app/file-logs/vco-server-app.log:2361:2025-10-30T15:38:16.404Z INFO vco [host='<vco pod b>' thread='WorkflowExecutorPool-Thread-14' user='<user>' org='<org id>' trace='-'] {|__SYSTEM|<user>:<workflow>:<workflow id>:token=<another token>2} ch.dunes.workflow.engine.mbean.helper.WorkflowHandler - ******** Workflow '<workflow>' (id: <workflow id>) has finished with status [ completed ]. Execution id: <another token>2 **********

Environment

• Aria Orchestrator 8.18.x

• Aria Assembler

Cause

The issue is caused by a duplicate event subscription configured in Assembler. Two separate subscriptions are actively listening for the same event topic (e.g., compute.provision.post) and are both configured to trigger the same Orchestrator workflow.

Resolution

To resolve this issue, you must identify and remove the redundant event subscription.

1. Navigate to Aria Assembler in the UI.

2. Review all configured event topic subscriptions, filtering for the topic ID in question (e.g., compute.provision.post).

3. Identify the subscriptions that target the same Orchestrator workflow, paying attention to project constraints.

4. Disable or delete the duplicate subscriptions, ensuring only one desired subscription remains active for that workflow and event topic.