Hi Filippo,
thanks a lot for your insights. This was very helpful.
Cheers
On Monday, May 9, 2016 at 5:46:50 PM UTC+2, Filippo De Luca wrote:
>
> Hi Peter,
> Assuming the actor has a status represented by a case class MyActorStatus.
> You need a way to write this status out and be able to reload.
>
> The akka-persistence uses the akka-serialization mechanism. It is an
> extension of Akka that you can use like this:
>
> private[this] var myStatus: MyActorStatus = _
>
> val serialization = SerializationExtension(actorSystem)
>
> def preStart(){
> super.preStart()
> myStatus = (for {
> bytes <- readStatus()
> status <- serialization.deserialize(bytes, classOf[MyActorStatus]
> } yield status).getOrElse(throw new Exception("Error recovering status"))
> }
>
> def postStop() {
>
> // I would save the satus async once in while as the backend could be
> //unavailable sometime.
> for {
> bytes <- serialization.serialize(myStatus)
> ok <- writeStatus(bytes)
> } yield ok
>
> super.postStop()
> }
>
> You can use this or another serialization depending on your persistence
> backend. It is a Sql DB you can use slick instead. If you are going to use
> something like s3 instead I think the akka serialization fit your needs.
>
> cheers
>
>
> On 9 May 2016 at 13:53, 'Peter' via Akka User List <
> [email protected] <javascript:>> wrote:
>
>> Hi Filippo,
>>
>> thanks for your answer. As also Patrick stated out, it seems to be the
>> better way to not go with akka persistence. But what I don't see, is an
>> very easy way with Serialisation. Can you probably give me a bit more about
>> what you have in mind?
>> In general, I need to make a snapshot of the actors state if this
>> changes. If the actor dies, this state needs to be recovered.
>>
>> Thanks, Peter
>>
>> On Monday, May 9, 2016 at 1:27:30 PM UTC+2, Filippo De Luca wrote:
>>>
>>> In my opinion you don't need akka-persistence at all. You just want to
>>> save the current actor state. It could be done very easily without
>>> akka-persistence using the Serialisation to serialize the status.
>>>
>>> On 9 May 2016 at 10:31, 'Peter Schrott' via Akka User List <
>>> [email protected]> wrote:
>>>
>>>> Dear Pros,
>>>>
>>>> From my Akka application it makes more sense to only use the snapshots.
>>>> I don't want to use the journal at all.
>>>>
>>>> Do you see any problems with doing that which I might not have
>>>> considered?
>>>>
>>>> My second problem with that is, that I wanted to delete old snapshots.
>>>> I.e. keep only the current one. The deletion should take place on the
>>>> SaveSnapshotSuccess. Initially I did not expect that the sequence
>>>> number is only updated at a journal logs. This of course makes sense after
>>>> thinking about it. But my problem remains, I can not identify my latest
>>>> snapshot as the sequence number stays at 0. I will always delete all
>>>> snapshots.
>>>>
>>>> Thanks for helping, Peter
>>>>
>>>> --
>>>> >>>>>>>>>> Read the docs: http://akka.io/docs/
>>>> >>>>>>>>>> Check the FAQ:
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>>>
>>>
>>>
>>> --
>>>
>>>
>>> [image: --]
>>> Filippo De Luca
>>> [image: http://]about.me/FilippoDeLuca
>>> <http://about.me/FilippoDeLuca?promo=email_sig>
>>>
>>>
>> --
>> >>>>>>>>>> Read the docs: http://akka.io/docs/
>> >>>>>>>>>> Check the FAQ:
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>
>
>
> --
>
>
> [image: --]
> Filippo De Luca
> [image: http://]about.me/FilippoDeLuca
> <http://about.me/FilippoDeLuca?promo=email_sig>
>
>
--
>>>>>>>>>> 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
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