Lock liquibase between validate and update

[joggeli34]

Lock liquibase for validate and update as suggested by:
liquibase/liquibase#2816 (comment)

Closes #25335

[geoand]

Thanks for the contribution.

Please format the code change according to the message above.

[famod]

I'm a bit puzzled by what is going to happen if this is run in conjunction with the upstream PR that resets some caches.
Do we have to roll back this change when that liquibase version lands?

[famod]

Is releaseLock() "lenient" in that it does not throw an exception if the lock has not been acquired?
What I have in mind is:

• waitForLock() fails with an exception
• finally kicks in
• releaseLock() fails (assumption!) because the lock has not been acquired
• the exception from finally shadows the one from waitForLock(), confusing the user

I'd move waitForLock() out of the try block or add a catch + addSuppressed() to the finally block.

This might seem like overengineering, but I had similar cases more often than not.

[famod]

So we're adding the overhead(?) of locking even in the case where we don't validate.

But given validate-on-migrate ist true by default it should be alright.

[joggeli34]

The overhead should be minimal, as the first thing liquibase.update() does is to acquire the lock. But if it already has it, it will result more or less in a map lookup, this should not generate much overhead.

[joggeli34]

The code must not be rollbacked after the upstream fix, as with this change it will prevent to load the changelog twice, once for validate and once for update

[famod]

Ok, so that upstream change (the reset) will not kick in with explicit locking because it'll bail out earlier because it detects that the db is already locked (by the locking approach of this PR).

Let's see what CI has to say.

[quarkus-bot]

Failing Jobs - Building 40bbf8c

Status	Name	Step	Failures	Logs	Raw logs
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✖	JVM Tests - JDK 17 MacOS M1	Set up runner	⚠️ Check →	Logs	Raw logs
✔️	JVM Tests - JDK 18

[gsmet]

Thanks!