You may consider creating a custom resolver (or extend the current ares resolver) to limit the number of addresses returned.
On Sunday, May 22, 2022 at 7:11:39 AM UTC-7 peter....@meraki.net wrote: > Thanks for the reply; I wanted to verify there wasn't some method that I > wasn't aware of. > It's a simple enough option to add and evaluate when creating the > PickFirstSubchannelList. > > I'm using the pick_first load balancer since I only want one subchannel > connected at any one time. > I want to limit the number of subchannels attempted by pick_first so that > a channel fails to TRANSIENT_FAILURE state faster if a smaller subset of > subchannels fail. > > On Friday, May 20, 2022 at 11:26:06 AM UTC-7 apo...@google.com wrote: > >> > Is there a method or option to limit the number of subchannels created >> to be fewer than the number of addresses resolved by ares? >> >> First, are you trying to limit the number of subchannels created, or the >> number of connections created? (note, a subchannel data structure takes >> some memory of course but does not necessarily have an active TCP >> connection associated with it). >> >> We don't have an option for limiting the number of subchannels. However, >> we do have a concept of load balancing policy (also see >> https://github.com/grpc/grpc/blob/master/doc/load-balancing.md#:~:text=The%20gRPC%20client%20supports%20an,and%20managing%20their%20connectivity%20behavior), >> >> which can be used as a coarse grained knob for configuring the number of >> active connections that a channel will have open. >> >> Some key points: >> - if you're using the pick_first load balancing policy (the default one), >> then the channel will try to maintain just one connection at a time, no >> matter how many addresses were resolved >> - if you're using the round_robin policy, then the channel will try to >> maintain one connection to each address that was resolved >> - there are other LB policies using lookaside load balancers linked to >> from >> https://github.com/grpc/grpc/blob/master/doc/load-balancing.md#:~:text=The%20gRPC%20client%20supports%20an,and%20managing%20their%20connectivity%20behavior >> >> >> >> On Monday, May 16, 2022 at 10:22:41 AM UTC-7 peter....@meraki.net wrote: >> >>> Hi, >>> >>> Is there a method or option to limit the number of subchannels created >>> to be fewer than the number of addresses resolved by ares? >>> >>> Is there anything in the execution chain: ares resolver -> server >>> address list -> address sorting -> subchannel list creation that can >>> ultimately reduce the # of subchannels created? >>> >>> Regards, >>> Peter Hurley >>> >> -- 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/0679cdee-4684-4890-9ce4-23624023f9e9n%40googlegroups.com.
