Cool I'll do that as part of the PR then. On Thursday, December 17, 2015 at 10:56:25 PM UTC+2, Patrik Nordwall wrote: > > > > On Thu, Dec 17, 2015 at 6:48 PM, Raymond Roestenburg < > raymond.r...@gmail.com <javascript:>> wrote: > >> I will try one more comment though, >> >> Why not put the two back-off supervisors in the akka.pattern package >> instead of one of them in contrib, and have the BackoffSupervisor props >> methods create one or the other (and give the props methods some good >> names)? >> The actual back-off supervisor actors could just be private. >> > > Sounds good to me. > > >> >> >> On Thursday, December 17, 2015 at 1:42:41 PM UTC+2, Raymond Roestenburg >> wrote: >>> >>> >>> >>> On Thursday, December 17, 2015 at 1:18:47 PM UTC+2, Patrik Nordwall >>> wrote: >>>> >>>> >>>> >>>> On Thu, Dec 17, 2015 at 11:58 AM, Raymond Roestenburg < >>>> raymond.r...@gmail.com> wrote: >>>> >>>>> Hi Patrik, >>>>> >>>>> Henry Mai looped me in on the existence of >>>>> the TransparentExponentialBackoffSupervisor in akka-contrib and PR >>>>> https://github.com/akka/akka/pull/18776 (thanks Henry!). >>>>> I find it confusing that there are two. As a user I would like one >>>>> BackoffSupervisor, in akka.pattern, not two, one of which is in contrib >>>>> (I >>>>> know, users always want the impossible!). >>>>> >>>> >>>> Me too. I tried, but failed. It was motivated by that they are >>>> different, and should be different classes. >>>> >>>> >>>>> >>>>> This is a very common pattern that pops up all the time which deserves >>>>> a spot in akka.pattern IMHO. >>>>> Almost any time you're working with some network you can't just use >>>>> the default supervisor stuff since it causes too fast reconnects, I think >>>>> it should be part of akka-actor, not akka-contrib. >>>>> >>>>> Both have the issue I was referring to, so I could implement the fix >>>>> in both now, sidestepping the issue of wanting just one version. >>>>> >>>>> But let me apply some logic, (subjective, possibly flawed :-) >>>>> >>>>> Are there any plans (or even possibility) to change the 'Stop >>>>> behavior' in akka persistence? >>>>> >>>> >>>> Why? We had flawed failure handling in Akka Persistence 2.3. We must >>>> enforce stopping of the persistent actor when there are journal failures, >>>> becuase the state must not diverge from what has actually been stored. >>>> http://doc.akka.io/docs/akka/2.4.1/scala/persistence.html#Failures >>>> >>> >>> Yeah, I'm just pushing buttons, trying to convince (in points below) >>> that there is a good reason for Stop in many cases to indicate failure, >>> which removes the arguments made against it being used to indicate failure. >>> Alright, if this has already been decided I'll just fix it in both >>> versions, no point flogging a dead horse. >>> >>>> >>>> >>>>> >>>>> If it does not, I'm assuming everyone agrees that Stop is a good >>>>> option to indicate failure (in certain scenarios), which I think means >>>>> that >>>>> there is a good reason to have options on one implementation. >>>>> >>>>> If Stop is not good to indicate failure, I would expect >>>>> akka-persistence to change, which also means there is just one version of >>>>> the BackoffSupervisor. >>>>> >>>>> But then, what happens if someone puts this in front of a remote >>>>> actor, where deathwatch (i.e Stop) is the only option to indicate >>>>> failure?... >>>>> >>>>> "Location transparency, anyone?" ;-) >>>>> >>>>> Cheers, >>>>> Ray >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> Cheers, >>>>> Ray >>>>> >>>>> On Wednesday, December 16, 2015 at 9:30:43 PM UTC+2, Raymond >>>>> Roestenburg wrote: >>>>>> >>>>>> Ok, I'll put a PR in for this. >>>>>> >>>>>> Cheers, >>>>>> Ray >>>>>> >>>>>> On Wednesday, December 16, 2015 at 7:09:59 PM UTC+2, Patrik Nordwall >>>>>> wrote: >>>>>>> >>>>>>> Sounds like a good improvement. PR is very welcome. >>>>>>> >>>>>>> Cheers, >>>>>>> Patrik >>>>>>> >>>>>>> On Tue, Dec 15, 2015 at 1:31 PM, Raymond Roestenburg < >>>>>>> raymond.r...@gmail.com> wrote: >>>>>>> >>>>>>>> BTW if you think this is a good idea, I would be happy to provide a >>>>>>>> PR for it (since I can't move to 2.4.1 yet anyway and I'm back-porting >>>>>>>> it >>>>>>>> right now). >>>>>>>> >>>>>>>> >>>>>>>> On Tuesday, December 15, 2015 at 2:28:36 PM UTC+2, Raymond >>>>>>>> Roestenburg wrote: >>>>>>>>> >>>>>>>>> Hey hAkkers, >>>>>>>>> >>>>>>>>> I'm trying out the new BackoffSupervisor (in 2.4.1) and there is >>>>>>>>> one thing that I did not really like (and please correct me if I am >>>>>>>>> wrong): >>>>>>>>> >>>>>>>>> There seems to be no way for the child to tell the >>>>>>>>> BackoffSupervisor that everything is ok again, the back-off is >>>>>>>>> automatically reset based on a duration of no errors: >>>>>>>>> >>>>>>>>> >>>>>>>>> https://github.com/akka/akka/blob/v2.4.1/akka-actor/src/main/scala/akka/pattern/BackoffSupervisor.scala#L204 >>>>>>>>> >>>>>>>>> https://github.com/akka/akka/blob/v2.4.1/akka-actor/src/main/scala/akka/pattern/BackoffSupervisor.scala#L207-L208 >>>>>>>>> >>>>>>>>> The minBackoff is both used as minimal back-off duration and as >>>>>>>>> this automatic reset duration. Which actually makes the minBackoff >>>>>>>>> hard to >>>>>>>>> set correctly, since it depends on the types of errors (and the speed >>>>>>>>> at >>>>>>>>> which the errors occur) in the child, and it makes it a bad idea to >>>>>>>>> set it >>>>>>>>> too low, since the back-off can then get stuck in repeating per >>>>>>>>> minBackoff >>>>>>>>> if the child does not crash fast enough the first time (within >>>>>>>>> minBackoff), >>>>>>>>> which means it will not properly back-off. >>>>>>>>> >>>>>>>>> >>>>>>>>> So in my case the child is something that connects over the >>>>>>>>> network and might crash, which could be a very fast error, or a very >>>>>>>>> slow >>>>>>>>> error. >>>>>>>>> A separate duration for reset would be a simple improvement, or >>>>>>>>> even better a message the child can send to the BackoffSupervisor to >>>>>>>>> indicate success (basically BackoffSupervisor .ResetRestartCount) and >>>>>>>>> a way >>>>>>>>> to disable the auto-reset at minBackoff. >>>>>>>>> >>>>>>>>> (I do appreciate that the BackoffSupervisor is done in such a way >>>>>>>>> that it can be dropped in between actors with hardly any change!) >>>>>>>>> >>>>>>>>> Cheers, >>>>>>>>> Ray >>>>>>>>> >>>>>>>> -- >>>>>>>> >>>>>>>>>> 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 https://groups.google.com/group/akka-user. >>>>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> -- >>>>>>> >>>>>>> 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 https://groups.google.com/group/akka-user. >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> >>>> >>>> >>>> -- >>>> >>>> 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 https://groups.google.com/group/akka-user. >> For more options, visit https://groups.google.com/d/optout. >> > > > > -- > > 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+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at https://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
