On Thu, Jan 8, 2015 at 9:37 PM, Matan Safriel <[email protected]> wrote:
> Thanks for the reminder. The Phi Accrual Failure Detector is nice, > although it is unfortunate that tuning the threshold is an art (see mention > of EC2 in http://doc.akka.io/docs/akka/snapshot/scala/remoting.html > <http://www.google.com/url?q=http%3A%2F%2Fdoc.akka.io%2Fdocs%2Fakka%2Fsnapshot%2Fscala%2Fremoting.html&sa=D&sntz=1&usg=AFQjCNGnALe52S3LT83NV9UJM17jhcxrVg> > ). > In practise the acceptable-heartbeat-pause is the only thing that you will adjust. > I wonder what may "inconsistent" mean in "In the face of communication > failures that are unrecoverable because the state of the participating > systems are inconsistent, the remote system becomes Quarantined. " > For example, system messages could not be delivered. System messages are used for things like watch, remote deployment, supervision. System messages are acknowledged and retried if lost and are therefore normally delivered reliably, but for example the system redelivery buffer is limited in size and if that is exceeded there is no way back, and the system must be quarantined. > > Thanks in advance! > > > On Thursday, January 8, 2015 at 6:29:48 PM UTC+2, bearrito wrote: >> >> Your first step would probably be the documentation at : >> http://doc.akka.io/docs/akka/snapshot/scala/remoting.html >> <http://www.google.com/url?q=http%3A%2F%2Fdoc.akka.io%2Fdocs%2Fakka%2Fsnapshot%2Fscala%2Fremoting.html&sa=D&sntz=1&usg=AFQjCNGnALe52S3LT83NV9UJM17jhcxrVg> >> >> In particular the sections - "Lifecycle and Failure Recovery Model" >> >> You could also have a look at http://doc.akka.io/docs/akka/ >> snapshot/general/configuration.html and any of the sections with >> keywords "gated,retry,quarantine" >> >> -b >> >> On Thursday, January 8, 2015 4:12:08 AM UTC-5, Matan Safriel wrote: >>> >>> Hi, >>> >>> I have read this other thread about the case of a remote being >>> unavailable >>> <https://groups.google.com/forum/#!msg/akka-user/68TuTZLxqFI/3toNcO8yvMMJ>. >>> I assume it still applies to the most current version (?). >>> >> No, that looks old. We have added support for remote death watch. > >>> My question is, how do both the supervision system (the part that's >>> above user code) and the death watch, in short, Akka, determine that a >>> remote is unavailable, and whether that is in any way configurable. I may >>> assume some polling is relied upon and wonder how exactly does it reach >>> that determination of "unavailability". >>> >> Heartbeat messages are sent between the nodes, and the inter-arrival times are fed into the failure detector, which detects unreachability. > >>> In the same vein, I would like to ask whether actors perform any sort of >>> retry of their own, in case they determine that they *failed* *sending >>> or replying to *a message. Or is it the case that message sending is a >>> "one time attempt". >>> >> No, normal message delivery is at-most-once <http://doc.akka.io/docs/akka/2.3.8/general/message-delivery-reliability.html>. There is an utility for at-least-once <http://doc.akka.io/docs/akka/2.3.8/scala/persistence.html#At-Least-Once_Delivery> delivery. > Pointers to relevant source code are also welcome. >>> >>> Thanks in advance, >>> Matan >>> >>> *P.S. in case relevant changes are on the roadmap, it would be also cool >>> to know about it.* >>> >> -- > >>>>>>>>>> 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. > -- 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 http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
