Hey Martin, thanks for the response. Definitely understand that there's not a requirement that the processor be aware of the View. However if the processors are dynamically created, and I need to have a View for each processor, then the creation of the views needs to be somewhat closely coupled to the creation of the processors. Right? That's what I couldn't get around and which led me to use pub/sub instead. The processors emit events which a single View actor aggregates.
On Tuesday, March 11, 2014 2:23:55 AM UTC-5, Martin Krasser wrote: > > > On 10.03.14 11:36, Mike wrote: > > Thanks Martin and Patrik. That makes sense but I have a number of views > that aggregate data in different ways. If I need to have a one to one > correspondence between Views and Processors, it seems like I would need to > tightly couple the creation of those Views to the Processors (or their > supervisors). This would tightly link these two parts of the application > when otherwise the processors don't need to have any knowledge of the > views. Am I going about this the wrong way? > > > Not sure I get your point. Processors are comepletely unaware of the > existence of corresponding views. Also, there's no coupling of the lifetime > of view actors and their corresponding processor actor. > > Does that answer your question? > > > On Friday, March 7, 2014 1:39:52 AM UTC-6, Patrik Nordwall wrote: >> >> >> >> >> On Thu, Mar 6, 2014 at 7:01 PM, Mike <wmf...@gmail.com> wrote: >> >>> Using an in memory projection seems to work great. The only limitation >>> I've run into (which may be just a limitation in my understanding ...) is >>> that a view can only monitor the event stream for a single processor. I >>> require a view to aggregate state across a large number of processors >>> >> >> Can't you achieve this by having many one-to-one Views that forwards >> the events to one aggregator actor? >> >> >>> so I've resorted to using a pub/sub mechanism. But is there a mechanism >>> or design to support a view monitoring a group of processors - for instance >>> via an ActorPath instead of a processorId? >>> >>> >>> On Thursday, March 6, 2014 10:07:16 AM UTC-6, Ryan Bair wrote: >>>> >>>> Thank you both. >>>> >>>> On Thursday, March 6, 2014 2:13:48 AM UTC-5, Patrik Nordwall wrote: >>>>> >>>>> >>>>> >>>>> >>>>> On Thu, Mar 6, 2014 at 8:08 AM, Martin Krasser <kras...@googlemail.com >>>>> > wrote: >>>>> >>>>>> Hi Ryan, >>>>>> >>>>>> >>>>>> On 05.03.14 21:35, Ryan Bair wrote: >>>>>> >>>>>> I'm working on a project where I would like to retain a history of >>>>>> actions performed against an entity and then leverage that history for >>>>>> business (what actions led the user to do X) as well as providing the >>>>>> user >>>>>> with information about past actions. >>>>>> >>>>>> Event Sourcing seems like it would provide a good way to accomplish >>>>>> this as the events are produced and stored as a regular part of the >>>>>> application flow, removing the need to do separate bookkeeping. I'm >>>>>> really >>>>>> impressed by Martin's work on the new Persistence module (and >>>>>> Eventsourced >>>>>> before it) and would like to move in that direction. However, I don't >>>>>> see a >>>>>> way to query the `journal` other than through recovery. >>>>>> >>>>>> Does it make sense to grow Persistence in this direction, or is there >>>>>> a better way to tackle what I am attempting? Perhaps simply querying the >>>>>> underlying data store directly? >>>>>> >>>>>> >>>>>> Generating query/read models (by projecting an event stream onto an >>>>>> in-memory data structure, tables in a database, or whatever) is an >>>>>> application-level concern. Akka-persistence is not meant to be a >>>>>> database >>>>>> with a query interface. Seems that Datomic is closer to what you're >>>>>> looking >>>>>> for. >>>>>> >>>>>> Just as a point of clarification, I'm looking to query the >>>> events themselves, not the resulting state. >>>> >>>>> >>>>> I agree, and would like to add that you can use a persistent View to >>>>> replicate the event stream to the query side, and there store a >>>>> representation that is optimal for these queries (e.g. in sql database). >>>>> >>>>> /Patrik >>>>> >>>>> >>>> I'm thinking I'll go this way and query the database directly. I might >>>> make a JDBC/slick journal implementation and use database views for the >>>> queries. >>>> >>>>> >>>>>> -- >>>>>> >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>> >>>>>>>>>> Check the FAQ: http://akka.io/faq/ >>>>>> >>>>>>>>>> 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 akka-user+...@googlegroups.com. >>>>>> To post to this group, send email to akka...@googlegroups.com. >>>>>> Visit this group at http://groups.google.com/group/akka-user. >>>>>> For more options, visit https://groups.google.com/groups/opt_out. >>>>>> >>>>>> >>>>>> -- >>>>>> 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://akka.io/faq/ >>>>>> >>>>>>>>>> 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 akka-user+...@googlegroups.com. >>>>>> To post to this group, send email to akka...@googlegroups.com. >>>>>> Visit this group at http://groups.google.com/group/akka-user. >>>>>> For more options, visit https://groups.google.com/groups/opt_out. >>>>>> >>>>> >>>>> >>>>> >>>>> -- >>>>> >>>>> Patrik Nordwall >>>>> Typesafe <http://typesafe.com/> - Reactive apps on the JVM >>>>> Twitter: @patriknw >>>>> >>>> -- >>> >>>>>>>>>> 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 akka-user+...@googlegroups.com. >>> To post to this group, send email to akka...@googlegroups.com. >>> Visit this group at http://groups.google.com/group/akka-user. >>> For more options, visit https://groups.google.com/groups/opt_out. >>> >> >> >> >> -- >> >> Patrik Nordwall >> Typesafe <http://typesafe.com/> - Reactive apps on the JVM >> Twitter: @patriknw >> > -- > >>>>>>>>>> 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 akka-user+...@googlegroups.com <javascript:>. > To post to this group, send email to akka...@googlegroups.com<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. 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