Hi John, The main problem with serializing ActorRefs directly is that they contain a unique identifier that identifies a current inhabitant of the corresponding actor path (see http://doc.akka.io/docs/akka/2.3.6/scala/actors.html#Actor_Lifecycle). Once the system is restarted and starts to replay the stored events the old UIDs will not match with the newly created actors. If you need to serialize references to certain actors you must serialize their path (ActorPath) and create an ActorSelection from them when you deserialize. Unfortunately you will need to resolve the ActorSelection with an Identify message to get the current ActorRef back, but there is no other way to do it. Of course this also relies on certain actors existing at a given path -- you might want to create them if they don't, but this depends on your use case.
-Endre On Tue, Oct 28, 2014 at 4:48 PM, John Stephen <[email protected]> wrote: > Hi, > > We are using Java, sharding and Akka persistence for our application > We have decided to use json serialisation of our objects / classes to > resolve sharding serialisation issues that we encountered in the cloud. > We are now trying to get Akka persistence to work by storing the journal > in DynamoDB. > We are using Jackson to perform the json serialisation. > > The serialisation does not seem to be a problem. We can store it in > DynamoDB as a string (so that we can view it manually). > But we have hit a problem when deserialising / replaying the journal items. > The classes have an actor reference that needs to be instantiated. > We tried to get access to the ExtendedActorSystem by calling > "JavaSerializer.currentSystem().value()" but this is returning a null > pointer (see snippet of code below) > > ActorRef deserializedActorRef = > JavaSerializer.currentSystem().value().provider().resolveActorRef(identifier); > > Does anybody know how to get access to the ExtendedActorSystem from a > custom serialiser ? > Or another way of resolving this problem ? > > Thanks > > John > > Notice: This email is confidential and may contain copyright material of > members of the Ocado Group. Opinions and views expressed in this message > may not necessarily reflect the opinions and views of the members of the > Ocado Group. > > If you are not the intended recipient, please notify us immediately and > delete all copies of this message. Please note that it is your > responsibility to scan this message for viruses. > > References to the “Ocado Group” are to Ocado Group plc (registered in > England and Wales with number 7098618) and its subsidiary undertakings (as > that expression is defined in the Companies Act 2006) from time to time. > The registered office of Ocado Group plc is Titan Court, 3 Bishops Square, > Hatfield Business Park, Hatfield, Herts. AL10 9NE. > > -- > >>>>>>>>>> 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. > -- Akka Team Typesafe - The software stack for applications that scale Blog: letitcrash.com Twitter: @akkateam -- >>>>>>>>>> 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.
