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!).
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? 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 < >> [email protected]> 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 [email protected]. >>> To post to this group, send email to [email protected]. >>> 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
