Re: [akka-user] migrating from an earlier version of akka-streams ..

wow, this is not definitely well described in the current documentation. I went through a similar chain of mistakes and misconceptions regarding the semantic of the new groupBy/merge primitives. Thanks Debassigh for bringing this here. Regards, Juanjo. El miércoles, 27 de abril de 2016,

Re: [akka-user] migrating from an earlier version of akka-streams ..

Thanks for the clarification. A good point to keep in mind. regards. On Wed, Apr 27, 2016 at 11:22 AM, Roland Kuhn wrote: > Hi Debasish, > > The current fusing algorithm is called «aggressive» for a reason: it will > fuse everything it can. To run the subflows in parallel

Re: [akka-user] migrating from an earlier version of akka-streams ..

Hi Debasish, The current fusing algorithm is called «aggressive» for a reason: it will fuse everything it can. To run the subflows in parallel you will have to add a .async after the fold. But that will only be beneficial if the monoid’s |+| is rather expensive. Regards, Roland Sent from my

Re: [akka-user] migrating from an earlier version of akka-streams ..

Thanks Roland a lot for the clarification .. I can do this .. val netTxn: RunnableGraph[Future[akka.Done]] = transactions.map(validate) .groupBy(MaxGroupCount, _.accountNo) .fold(TransactionMonoid.zero)(_ |+| _) .mergeSubstreams Only difference

Re: [akka-user] migrating from an earlier version of akka-streams ..

> 26 apr 2016 kl. 20:14 skrev Debasish Ghosh : > > Just for the sake of completeness, this works .. > > transactions.map(validate) > .groupBy(MaxGroupCount, _.accountNo) > .fold(Map.empty[String, Transaction])((l, r) => l |+| > Map(r.accountNo

Re: [akka-user] migrating from an earlier version of akka-streams ..

The fold will be sequential On Tue, Apr 26, 2016 at 9:20 PM, Debasish Ghosh wrote: > Actually I realized just now that I don't need the groupBy and > mergeStreams for this .. Just the following will also do .. > > transactions.map(validate) >

Re: [akka-user] migrating from an earlier version of akka-streams ..

Actually I realized just now that I don't need the groupBy and mergeStreams for this .. Just the following will also do .. transactions.map(validate) .fold(Map.empty[String, Transaction])((l, r) => l |+| Map(r.accountNo -> r)) And the example in the Streams Cookbook for counting

Re: [akka-user] migrating from an earlier version of akka-streams ..

Just for the sake of completeness, this works .. transactions.map(validate) .groupBy(MaxGroupCount, _.accountNo) .fold(Map.empty[String, Transaction])((l, r) => l |+| Map(r.accountNo -> r)) .mergeSubstreams Since I cannot access the sub-streams I need to

Re: [akka-user] migrating from an earlier version of akka-streams ..

If you can devise a safe version of groupBy that lets us preserve that nice quality then I am more than all ears. -- Cheers, √ On Apr 26, 2016 8:02 PM, "Debasish Ghosh" wrote: > Thanks Viktor .. my main issue is that we lose the natural semantics of > groupBy as we

Re: [akka-user] migrating from an earlier version of akka-streams ..

Thanks Viktor .. my main issue is that we lose the natural semantics of groupBy as we learnt from SQL. We cannot access the substreams as separate abstractions that groupBy creates. On Tue, Apr 26, 2016 at 11:28 PM, Viktor Klang wrote: > Debasish, > > The problem with

Re: [akka-user] migrating from an earlier version of akka-streams ..

Debasish, The problem with groupBy was that it was too easy to create leaks and silently broken solutions with it, but I sympathize with your situation, I also felt the original as being more ergonomic. I think there is room for improvement in the current solution. -- Cheers, √ On Apr 26, 2016

Re: [akka-user] migrating from an earlier version of akka-streams ..

Roland - The problem is I cannot access the substreams separately within the fold. In the earlier solution the fold was on individual substreams (not on the whole stream). Here the fold gets *all* the elements from all substreams and I lose the ability to process substreams separately. Hence I

Re: [akka-user] migrating from an earlier version of akka-streams ..

Instead of using a fold sink which materializes to a Future you’ll need to use a fold combinator which produces the result as its only value after the substream has completed, i.e. you keep the computation results within the streaming domain a bit longer instead of going to the Future domain

[akka-user] migrating from an earlier version of akka-streams ..

Hi - I am trying to migrate some akka-streams code from an earlier version (akka-stream-experimental 1.0.RC4) .. please have a look at the following .. /** * Create multiple streams out of a single stream. The stream "transactions" is being * demultiplexed into many streams split by account