Team, Consider I have domain model Bank Customer'*s* Account's
Bank object will have many customers. Every customer will have multiple accounts. Consider I implement the above model using akka persistence. For the sake of discussion consider I make each as different Aggregate Roots using PersistentActor's. I want to implement a query : Give my all customers whose balance is less then 100$. Do you mean, 1. Create one PersistentView XYZ. 2. This XYZ will listen from all 3 AR's. 3. PersistentView XYZ will replicate these events as state to some DB consider cassandra. 4. Client will query directly cassandra to find "all customers whose balance is less then 100$". Is my understanding correct? If not, can you let me know how to achieve this using PersistentView? -Prakhyat M M On Tuesday, 19 August 2014 22:49:14 UTC+5:30, Martin Krasser wrote: > > > On 19.08.14 18:48, delasoul wrote: > > As I am no Spark expert - will it be used only as kind of > messaging(streaming) middleware to sync write and read store or also to > somehow change/merge/ > filter the events it gets/pulls from the write store > > > usually, to process (transform/aggregate/filter/...) these events. > > or is this all done via the plugin for PersistentViews? > (I guess it has to be like this, otherwise using only one backend store > cannot be supported?) > > thanks, > > michael > > On Tuesday, 19 August 2014 17:48:16 UTC+2, Martin Krasser wrote: >> >> >> On 19.08.14 17:41, Ashley Aitken wrote: >> >> >> >> On Tuesday, 19 August 2014 19:33:55 UTC+8, Martin Krasser wrote: >>> >>> If so, it sounds like a great solution but why would that require an >>> extension to the Akka Persistence design/API? >>> >>> >>> Because transformed/joined/... event streams in backend store on the >>> read side must be consumable by PersistentViews (for creating read models). >>> I still see this backend store to maintain changes (= >>> transformed/joined/... events) instead of current state. >>> >> >> I am sorry I still don't see this. >> >> This suggests to me that spark is talking directly to the read model >> datastore (e.g. graph database, MongoDB, SQL database). >> >> So are you suggesting: >> >> 1. journal -> spark -> Akka actors (like PersistentView) -> read model >> data store >> >> or >> >> 2. journal -> spark -> read model data store (like graph database, >> MongoDb, SQL database) -> Akka actors <- Queries >> >> >> I was suggesting 2. >> >> >> I see PersistentView(for generalised topics) as the glue between the >> Akka journal (write store) and read stores (1.). >> >> Thanks for your patience. >> >> 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. >> >> >> -- >> Martin Krasser >> >> blog: http://krasserm.blogspot.com >> code: http://github.com/krasserm >> twitter: http://twitter.com/mrt1nz >> >> -- > >>>>>>>>>> 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 http://groups.google.com/group/akka-user. > For more options, visit https://groups.google.com/d/optout. > > > -- > Martin Krasser > > blog: http://krasserm.blogspot.com > code: http://github.com/krasserm > twitter: http://twitter.com/mrt1nz > > -- >>>>>>>>>> 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.
