Troubleshooting Federation "Stopping Link" Messages in RabbitMQ

Products

• VMware Tanzu RabbitMQ

Issue/Introduction

In some cases, federation issues can arise when an upstream or policy references a queue that no longer exists or was never created. This can lead to "stopping link" messages, which indicate that the system is unable to find the referenced queue. This issue may occur due to one of the following:

• The queue has been deleted or was never created.

• A policy is still referencing a non-existent queue.

• The policy itself is misconfigured.

Cause

The core issue typically stems from a mismatch between the federation policy and the actual state of the queues. This may happen if:

1. A queue that a policy references has been deleted.

2. A policy continues to point to a queue that no longer exists.

3. The policy configuration itself is incorrect or outdated.

This situation can lead to "stopping link" errors and interrupt normal federation behavior, as the system cannot establish a connection with the missing queue.

Resolution

To improve the stability of federated systems and prevent issues like this from occurring in the future,  we can take following actions:

1. Avoid Using Classic Queues: Classic queues may be less reliable, especially in federated environments. If possible, consider migrating to more resilient queue types to ensure better availability and consistency.

2. Minimize Frequent Queue Changes: Frequently creating and deleting queues can lead to inconsistencies between what the policy expects and what is actually available. It's important to adopt a stable approach for queue management to prevent unexpected disruptions.

3. Use Quorum Queues or Exchanges: Quorum queues (QQs) offer higher reliability and fault tolerance than classic queues, especially in environments with federation. Alternatively, you can use exchanges to route messages, reducing dependency on specific queues.