On Sat, Feb 11, 2017 at 4:57 PM, 'Michael Rose' via grpc.io < grpc-io@googlegroups.com> wrote:
> A few questions: > > 1) Under this design, is it possible to add a load balancing constraints > for retried/hedged requests? Especially during hedging, I'd like to be able > to try a different server since the original server might be garbage > collecting or have otherwise collected a queue of requests such that a > retry/hedge to this server will not be very useful. Or, perhaps the key I'm > looking up lives on a specific subset of storage servers and therefore > should be balanced to that specific subset. While that's the domain of a LB > policy, what information will hedging/retries provide to the LB policy? > > 2) "Clients cannot override retry policy set by the service config." -- is > this intended for inside Google? How about gRPC users outside of Google > which don't use the DNS mechanism to push configuration? It seems like > having a client override for retry/hedging policy is pragmatic. > > 3) Retry backoff time -- if I'm reading it right, it will always retry in > random(0, current_backoff) milliseconds. What's your feeling on this vs. a > retry w/ configurable jitter parameter (e.x. linear 1000ms increase w/ 10% > jitter). Is it OK if there's no minimum backoff? > I was about to ask the same thing :) The current text: The failed RPCs will be retried after *x* seconds, where *x* is defined as random(0, current_backoff). What I would instead expect: The failed RPCs will be retried after *x* seconds, where *x* is defined as random(current_backoff*(1-jitter), current_backoff*(1+jitter)) where jitter would be 0.25, for example, to indicate 25% jitter. > Regards, > Michael > > On Friday, February 10, 2017 at 5:31:01 PM UTC-7, ncte...@google.com > wrote: >> >> I've created a gRFC describing the design and implementation plan for >> gRPC Retries. >> >> Take a look at the gRPC on Github >> <https://github.com/grpc/proposal/pull/12>. >> > > *CONFIDENTIALITY NOTICE: This email message, and any documents, files or > previous e-mail messages attached to it is for the sole use of the intended > recipient(s) and may contain confidential and privileged information. Any > unauthorized review, use, disclosure or distribution is prohibited. If you > are not the intended recipient, please contact the sender by reply email > and destroy all copies of the original message.* > > -- > 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 post to this group, send email to grpc-io@googlegroups.com. > Visit this group at https://groups.google.com/group/grpc-io. > To view this discussion on the web visit https://groups.google.com/d/ > msgid/grpc-io/62809dba-3349-4a60-9aa9-ccc044d27f53%40googlegroups.com > <https://groups.google.com/d/msgid/grpc-io/62809dba-3349-4a60-9aa9-ccc044d27f53%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- 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 post to this group, send email to grpc-io@googlegroups.com. Visit this group at https://groups.google.com/group/grpc-io. To view this discussion on the web visit https://groups.google.com/d/msgid/grpc-io/CAO78j%2BJDAH1LQ5-OjdtUwKaE%2BJGg2y6p5-Gte3BMtV0nSj2dZg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
