Hi Daniel, 11 mar 2014 kl. 09:13 skrev Daniel Wang <[email protected]>:
> Akka core developers, congratulations for the 2.3.0 release. My team are > using it to develop our product right now. Thank you. > > One thing we are discussing (and still haven't come to an conclusion) is how > to make sure all persistent events (commands if we use command-sourcing) will > be backward compatible. We can certainly use protobuf WDL to defined all > events/commands (and I did try), but it turns out working with Java POJO > classes with Akka is so unnature as we are all spoiled by pattern matching. I > also tried to use Twitter's scrooge to compile thrift files into scala code > (so all thrift structs are case classes), but I didn't manage to come up with > a general serializer (by 'general' I mean there is no need to serialized each > event/command type case-by-case as the protobuf serializer). I'm going to try > Kryo serializer soon. I wish I can have some luck. What we do with our own messages is to use the generated protobuf Java classes only as an intermediate step during serialization/deserialization so that we can work with case classes (for the reasons you state as well). This conversion will also help you decouple the versioning logic from the business logic, i.e. when you deserialize an old version of an event the conversion into a case class can synthesize defaults for those fields which are missing. > Processor's in-memory state snapshots are also need to be backward > compatible, otherwise each upgrade of events/commands will reply all history > events/commands, given events/commands persistence are backward copyable. The > idea on my mind is to 1) convert the scala-collection based memory snapshot > into a huge thrift/protobuf strutter, then 2) serialize the thrift/protobuf > structure to byte arrays. To make the conversion async (not to block > processor event loop), I may have to write a customer serializer. Yes, this sounds about right. Regards, Roland > > It will be great if someone from the Akka dev team can comment and share > their thoughts. > > > > -- > >>>>>>>>>> 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. Dr. Roland Kuhn Akka Tech Lead Typesafe – Reactive apps on the JVM. twitter: @rolandkuhn -- >>>>>>>>>> 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.
