Running Hazelcast put() and replace() calls in the calling thread

Question

Is it possible to force Hazelcast to run put(), replace(), and delete() methods on the TransactionalMap on the calling thread? I want the XA transaction to carry over from writing to Hazelcast to writing to the database in the MapStore, but Hazelcast is queueing the changes to be run on other threads, so they aren't in the same transaction context.

I've got it set up as a write-through persistence, but I see that it's queueing the TxnSetOperation and running them on a separate thread.

This is in a Spring Boot application using the Hazelcast autoconfiguration with a JPA / Hibernate store backing to PostgreSQL.

Answer 1

MapStore operations don't run in the same transactional context. If you want transactional persistent updates with Hazelcast, you need to use XA transactions and not enable MapStore. Then you can set the persistent store as a different XA resource in your context. You can have a check the related section in Hazelcast's reference manual: http://docs.hazelcast.org/docs/latest/manual/html-single/index.html#providing-xa-transactions

Answer 2

Alsparlan's answer is partially correct, but there's no way to enlist a resource in a MapStore with the same transactional context as your actions against the Hazelcast TransactionalMap. The link he provided does NOT talk about this (unfortunately), but the Javadoc for TransactionalMap does:

When using MapStore, the call to any MapStore method is outside the transactional boundary. If you need to have an XATransaction spanning Hazelcast operations and one more other XAResources (such as a database), you should not use MapStore. Instead, enlist both resources in a transaction

I've removed my MapStore usage and wired my Spring Boot repositories directly into my services so I can make my changes to Hazelcast and my datasource in the same service methods inside the same transaction. Along with this solution to declaratively enlisting the Hazelcast XAResource this is working for me now.