Cannot install a secondary instance that ingests from the same audit queue as the primary instance

[ramonsmits]

Describe the bug

Description

When installing SC it shows an error when adding a secondary instance that is already configured to read from the same queue:

Expected behavior

Allow multiple instance to be installed. This is also allowes when scaling out over multiple machines so should also be allowed on the same machine.

Versions

4.30.0

Steps to reproduce

1. Add first instance
2. Add secondary instance that ingest from the same queue
3. Observe the error message "Audit queue is already assigned to another instance" in SCMU installer

Relevant log output

No response

Additional Information

Workarounds

Maybe add the instance via powershell?

Possible solutions

Additional information

[awright18]

Is this a regression? I'm not sure that when the validations were updated that this requirement was known.

[ramonsmits]

I don't know, its an observation and to me it doesn't make sense to enforce this.

It would also just be a warning or require a "trust me, I know what I'm doing" check.

[awright18]

@ramonsmits I ran across this documentation about azero downtime upgrades that suggests using a remote audit instance that ingests messages from the same audit queue. So there is a scenario where that would be needed, but I don't believe this specific scenario is supported by the Service Control Management application.

[ramonsmits]

There is not much to "support" except that besides not blocking the port to also add the audit instance to the config of the primary instance.

[mauroservienti]

Would that work using PowerShell?

[ramonsmits]

Would that work using PowerShell?

Not sure, would need to test it

[awright18]

I'm not sure what the "Add-ServiceControlRemote" command actually does. I'm definitely in favor of removing this same audit queue restriction, especially if it would make RavenDB migrations from 3.5 to 5 simpler.