Thanks again Martin. On Tuesday, 6 May 2014 14:37:48 UTC+8, Martin Krasser wrote: > > Good so I am on the write track. I am confused a little about the Views > keeping stage in memory and with snapshots. What state would this be? > Surely the read model itself is maintaining most of the state, e.g. in a > database. Could the Views themselves sometimes be the read model that were > queried by the client? Is that meant to be the primary approach or not? > > > Yes, this is meant to be the primary approach. >
So, please correct me if I am wrong, the View(s) are a front for the read model, which is stored either 1) inside each View object's state or 2) in a hidden backend store? Which one of those is most common? Or something else? Views that track updates from many processors make absolutely sense and >> have already been requested several times (see ticket). >> > > I won't ask when we can hope for a solution but I will ask (not > necessarily you but anyone reading) what are people doing until then? > > There are several options, some are > > - Let the backend store (Cassandra, MongoDB or whatever) update custom > views (e.g. database tables) whenever a new message is added to the journal > (using triggers). > Are you talking about the backend store for the journal (for which LevelDB is the default)? And that when a new event is added to the backend store / journal a trigger fires that updates custom denormalised entries for the read model? - Let processors update a database directly to create a view (via channels > to avoid duplicates during replay). > I'm not so sure I understand this one. Let the Processor update the domain model AND the read model backend store? I guess that's possible if it is on the same node. And use a Channel to ensure the read model doesn't get redundantly updated. Processor =Channel=> Actor (which is the read model or updates the backend store)? Cheers, Ashley. -- >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>>>>>> Check the FAQ: >>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups "Akka User List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
