Customers that want to use JBossCache 2.x might be reluctant to
migrate their data from one format to the other. I can see how an
existing customer might think this is a proper pain in the ass,
independent of the benefits, and might reduce adoption among them.
We want to remove barriers upgrading, but at the same time, we want
new customer to use new marshalling, so I'd actually implement the
possibility to use 1.x marshalling which is plan java serialization at
the CacheLoader level. This could easily achieved adding a property to
the <properties> section.
The default in 2.x should be to use VAM and only people who are
resilient to change their existing stores to VAM should use the 1.x
option, which would need explicitly definition.
This option also makes it easier for migration purpouses as customers
should be able to start two cache instances with different cache loader
marshalling method set. They could then loop through the first one using
get operations and call put in the second instance.
Just note that this does not apply to the marshalling done at
replication level as there's no hard data that needs migrating.