Hello,

I'm trying to port hibernate lucene support to SOLR. Digging through the code, I found out the lucene index is updated after transaction is successfully completed.

This ensures that in the case of a rollback, the index is not artificially updated.

However, wouldn't it be nice if we could push the integration further, such as that in the case of a Lucene index update failure, the transaction is rolled back? Basically, the lucene update should be included in the transaction.

This could be done using index updates for post-insert, post-update, post-delete events. But then the nice mechanism of processing queues of index update messages would be lost (another reason would be that if db operation fails, index is inconsistent).

Implementing the Synchronization interface, unfortunately is not helpful - it does not allow to rollback a transaction. So my question is: can this be achieved? and how ?

Thanks,
Marius Hanganu

It can only be achieve by some sort of 2 Phase-Commit protocol, but it's a lot of work.
Do you really think DB transaction should rollback is case indexation is failing? In most systems, Indexation is a nice-to-have feature while a DB operation is a must-have. You can always try and reindex.

BTW, what do ou mean by

I thought about using SOLR as the back-end Hibernate Search as an alternative to direct Lucene calls, this might be (at least partially) possible. But I don't know how useful such a feature would be

We use SOLR as an indexing engine for our application, and db sync with solr is required.

When I said "porting" I should have probably said "small adaptation", since I'm using far lesser features than the ones in the engine you've wrote.

The use case is that someone decided for SOLR as indexing engine. Deciding btw SOLR and lucene is another topic (basically related to the features SOLR provides).

OK Cool.
Tell me how you did it when you're done, That might be a nice additional feature to add to Hibernate Search.

BTW, can you describe the top 5 features that made you choose SOLR instead of straight Lucene?