Krishna, I'll mention that we also have a short guide on custom LBs <https://grpc.io/docs/guides/custom-load-balancing/> that can help you with the fundamentals.
On Monday, November 6, 2023 at 3:53:01 PM UTC-8 Larry Safran wrote: > Yes, you will need a custom NameResolver. > You could have your NameResolver do one of the following > 1) Extend DnsNameResolver (as is done by the internal GrpcNameResolver) > and override the doResolve method > 2) Directly extend NameResolver and have a field with a DnsNameResolver > created through the DnsNameResolverProvider (which should be gotten from > the registry). > > There is already a load balancer that is switching between 2 child load > balancers. It is experimental and can be specified as > "priority_experimental". What it does is to use a specific attribute that > must be set by the NameResolver. Even if you go with your own load > balancer, that would be the best way to differentiate which addresses > should be used for which child. If you want to use it as an example, it is > https://github.com/grpc/grpc-java/blob/master/xds/src/main/java/io/grpc/xds/PriorityLoadBalancer.java > > > > On Mon, Nov 6, 2023 at 1:53 PM Krishna Sai Veera Reddy < > krishnasaiv...@gmail.com> wrote: > >> Hey Larry, >> >> Thank you for your response! Are there any examples out in the wild on >> how to do this? Also the part that is confusing me is the name resolution. >> Do we have to add a custom name resolution policy as well so that we get >> both the LB and round robin IP addresses in `acceptResolvedAddresses >> <https://github.com/grpc/grpc-java/blob/master/examples/src/main/java/io/grpc/examples/customloadbalance/ShufflingPickFirstLoadBalancer.java#L66>` >> >> method in the LB policy? >> >> On Friday, November 3, 2023 at 12:50:20 PM UTC-7 Larry Safran wrote: >> >>> This is a perfect scenario for a custom LB policy. Since LB policies >>> form a tree, you could easily have your policy delegate to either a >>> PickFirst or RoundRobin policy depending on whether or not the LB is up. >>> Just have your policy define a ForwardingLoadbalanceHelper whose >>> updateBalancingState passes the picker from the oppropriate downstream >>> policy. >>> >>> On Fri, Nov 3, 2023 at 12:29 PM Krishna Sai Veera Reddy < >>> krishnasaiv...@gmail.com> wrote: >>> >>>> Hello All, >>>> >>>> I am working on a gRPC client that connects to a gRPC service fronted >>>> by an LB but would like the client to automatically fallback to using >>>> round-robin DNS to directly connect to the backend servers when the LB >>>> goes >>>> down. How do I go about this? Would I need to implement my own custom LB >>>> policy? Any help is appreciated and thanks in advance! >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "grpc.io" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to grpc-io+u...@googlegroups.com. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/grpc-io/df8f4a85-5020-4c68-bb94-cbea67d7c75an%40googlegroups.com >>>> >>>> <https://groups.google.com/d/msgid/grpc-io/df8f4a85-5020-4c68-bb94-cbea67d7c75an%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "grpc.io" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to grpc-io+u...@googlegroups.com. >> > To view this discussion on the web visit >> https://groups.google.com/d/msgid/grpc-io/2e7b95aa-cd66-40f5-bf41-0484fa12892cn%40googlegroups.com >> >> <https://groups.google.com/d/msgid/grpc-io/2e7b95aa-cd66-40f5-bf41-0484fa12892cn%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "grpc.io" group. To unsubscribe from this group and stop receiving emails from it, send an email to grpc-io+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/grpc-io/51db24a6-3faa-4f9e-a979-54a0d5368921n%40googlegroups.com.
