Thanks, Roland On Wednesday, February 15, 2017 at 11:28:59 PM UTC+2, rkuhn wrote: > > > 15 feb. 2017 kl. 22:18 skrev Igor Berman <[email protected] <javascript:> > >: > > Hello All > Wanted to get a bit of advice regarding following usecase: > I have local ActorSystem that handles messages with some key inside. Every > such message causes mutation of db state by the key: read old value by key, > compute new state given message, write new value to the db. > > To guarantee consistent update per each key I thought of spliting > processing of incoming messages by ConsistentHashingPool, so that all > messages with same key will be handled by the same child actor. Number of > children will give me sort of partitioning of key-set into finite number of > actors, it will provide concurrency of updates across keys from different > partitions too. Suppose I can't use akka-persistence module and need to > maintain "state" inside this db. > > Now concerning implementation of update itself: if I wrap processing in > some future (so that actor won't be blocked to read from db and to write to > db) and then pipe the result to the sender I might break the order of > processing within same key(e.g. when update logic running in future for > some msg is not yet finished write to db, the next msg will be taken from > mailbox by actor and will submit another processing that might interleave > with the first one), so I found technique of becoming "unresponsive" and > stashing all messages and then, when future completes unbecoming and > unstashing all messages(from here > http://chariotsolutions.com/blog/post/order-chaos-maintaining-ordered-processing-messages-akka-actors/ > ) > > On the other hand, I'll need some thread pool anyway for those > futures(since reads/writes are blocking), so maybe just doing this blocking > work inside actor and configuring it with custom dispatcher will give same > effect, while being more simple solution > > > Yes, this is the right conclusion: Actors establish order within chaos and > manage resources. > > Regards, > > Roland > > > thanks in advance > Igor > > -- > >>>>>>>>>> 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] <javascript:>. > To post to this group, send email to [email protected] > <javascript:>. > Visit this group at https://groups.google.com/group/akka-user. > For more options, visit https://groups.google.com/d/optout. > > >
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