Why WildFly model does not offer operation to force recovery to be run

[ochaloup]

On working on task [CLOUD-2262] Provide support for transaction recovery for transactions which contain subordinate transactions propagated… I was asked by jmesnil why is the recovery scan not exposed as a management operation in the transaction subsystem.

As I'm not sure about design decision behind I decided to move the question here to hopefully find more details.

My answer to this question would be that

forcing the recovery is not a standard operation that is about to be offered to a usual user. It's internal Narayana procedure which is not expected to be touched. It's helpful only for a person who really understands how Narayana works and what happens when it's called. It's useful for testing and for integration purposes. But I can't imagine that would be useful for an ordinary developer to force the recovery processing.

But a little bit against this logic there is defined a socket binding in the configuration (WildFly 17.0 Model Reference ). It is possible to communicate with the recovery manager through that socket to force the operation. Why that was not transferred to be an model operation?

Thanks

Ondra

[tomjenkinson]

Personally I think it would be fine to add it as an enhancement to WildFly. It is niche to need do it but it could be added. As you say, for a long time in standalone we have allowed connecting to the socket to trigger the scan. IIRC recovery-listener is disabled by default.

[mmusgrov]

ochaloup  wrote:

But a little bit against this logic there is defined a socket binding in the configuration (WildFly 17.0 Model Reference ). It is possible to communicate with the recovery manager through that socket to force the operation. Why that was not transferred to be an model operation?

Socket management is a big issue for many users so we expose the recovery socket to allow users to change the port.

I agree that we do not have a use case for adding a "trigger recovery operation": developers and tooling can use the socket to trigger recover scans and tooling can use internal mechanisms.

[ochaloup]

The work on the operation is to be tracked at the issue [WFLY-12610] Provide a proper :recover management operation for transactions - JBoss Issue Tracker