"Cluster-safe database upgrades" liquibase benefit mentioned - what does this mean?

General Discussion
1

Team,

I noticed this term was used

    Cluster-safe database upgrades

on

http://www.liquibase.org/

Does anyone know exactly what is meant by it and how liquibase supports this through it’s framework?

Thanks

2

I think it simply means that a lock table is used to perform migrations. Thus, if 2 instances of an application execute migrations at the same time, one is performing and the other one is waiting until the lock is free again.

3

Yes although it would seem odd for two separate processes to be attempting to process upgrades against the database at the same time.

4

The main use case is when you have Liquibase to auto-run on startup of a web application, and you have a cluster of servers that may end up being started at the same time…

Nathan