Jari, Yes an asynchronous queue is definitely an option. I've actually used that approach before. It makes a lot of sense when trying to achieve high throughput since the audit logging can then be done on lower priority.
I was however hoping to be able to use JPA for this since a queue increases the complexity significantly (also regarding testing). Thanks, /Bengt 2011/7/7 Jari Fredriksson <ja...@iki.fi> > 7.7.2011 14:05, Bengt Rodehav kirjoitti: > > I'm using OpenJPA for persistence and would like to audit log any changes > > made to my entities. I serialize the objects to JSON (with Gson) and > store > > them in a separate table in the database. Since the audit log needs to > have > > the correct id's, the audit logging must take place after the entity has > > been persisted. > > > > I was hoping I could use the @PostPersist and @PostUpdate life cycle > > callbacks for this. I do seem to have the right information available and > > the serialization works fine but I don't know how I can persist my audit > log > > entries at this point. From what I've read, I'm not allowed to use the > > entity manager in a "Post" lifecycle callback which of course makes this > > hard. > > > > What do you recommend? Is there a good place in JPA/OpenJPA where I > > automatically can trigger the storing of an audit log entry as described > > above. Of course I can move this logic up from the persistence layer to a > > place where I can first have the entity manager persist my entity and > then > > explicitly call another service to do the audit log. However, this is a > > pretty general mechanism that I would like to have automatic support for > in > > my framework which is why I would like to have it pushed down into the > > persistence layer. > > > > Any ideas? > > > > I have not done anything like this, but some kind of queue and a > separate processor for that queue might be a solution. > > Maybe some message queue? Or a singleton Hashtable containing entries, > and a separate thread for persisting these to database. > > Something like that. > > > > -- > > AWAKE! FEAR! FIRE! FOES! AWAKE! > FEAR! FIRE! FOES! > AWAKE! AWAKE! > -- J. R. R. Tolkien > >
