How to use compensating API implements a xa dasource?

[kylin]

We have developed a MongoDBManagedConnectionFactory, which add Ra to WildFly via CLI

/subsystem=resource-adapters/resource-adapter=mongodbQS:add(module=org.jboss.teiid.resource-adapter.mongodb)
/subsystem=resource-adapters/resource-adapter=mongodbQS/connection-definitions=mongodbDS:add(jndi-name=java:/mongoDS, class-name=org.teiid.resource.adapter.mongodb.MongoDBManagedConnectionFactory, enabled=true, use-java-context=true)
/subsystem=resource-adapters/resource-adapter=mongodbQS/connection-definitions=mongodbDS/config-properties=RemoteServerList:add(value=${mongodb.serverlist})
/subsystem=resource-adapters/resource-adapter=mongodbQS/connection-definitions=mongodbDS/config-properties=Database:add(value=${mongodb.dbname})
/subsystem=resource-adapters/resource-adapter=mongodbQS:activate

then get ConnectionFactory via jndi. But the above implementation not support XA requirement, I am in wonder,  whether can we use compensating API to enhance ManagedConnectionFactory implmentation that let mongo data source to satisfy XA requirement? Can we use compensating API to implement?

[gytis]

Compensating transactions implement a different protocol to the XA. You can surely use compensating transactions to assure atomic outcome in your application. Just keep in mind, that at the moment crash recovery is not yet implemented (although it is in our plans). Other than that it's fully functional.

There are a couple of posts in our blog from a couple years back, which you can read to get yourself more familiar with compensating transactions: Narayana team blog: Compensating Transactions: When ACID is too much (Part 1: Introduction), Narayana team blog: Compensating Transactions: When ACID is too much (Part 2: Non-Transactional Resources).

Also try our quickstarts: quickstart/compensating-transactions at master · jbosstm/quickstart · GitHub.

[gytis]

In theory I think it should be possible to bridge XAResource to the compensating transaction, which could control MongoDB. But at the moment it's just a speculation, I would need a bit more time to think about this.

p.s. we have a JIRA for the opposite scenario to yours: [JBTM-1680] Allow 2PC participants to enlist in a compensation-based transaction - JBoss Issue Tracker. But since we never had such requirement, nobody worked on it up to now.

[smarlow]

[1] does not answer your question but you may want to follow the discussion and contribute as well.  It might be interesting for you to describe how you are using MongoDB in your application (in terms of what types of components are reading/writing MongoDB). 

Regards,

Scott

[1] update on WildFly NoSQL prototype integration...

[kylin]

Thanks, I would list the requirement jiras in Teiid:

• [TEIID-3907] Support compensating transactions for updatable non-XA sources - JBoss Issue Tracker
• https://issues.jboss.org/browse/JBDVPL-302
• [TEIID-2957] MongoDB: Implement Compensating transactions - JBoss Issue Tracker

[gytis]

kylin, could you paste the link to your source code?

[tomjenkinson]

Hi Kylin,

Please can you provide a link to your source code so Gytis can take a look?

Thanks,

Tom

[tomjenkinson]

Hi kylin, how did you get on with this? Can we help you further?