Skip to content
Unverified Commit 88258b40 authored by Pavlo Khrystenko's avatar Pavlo Khrystenko Committed by Pavlo Khrystenko
Browse files

rpc v2: backpressure `chainhead_v1_follow` (#6058)



closes #5871

> The chainHead_v1_follow is using unbounded channels to send out
messages on the JSON-RPC connection which may use lots of memory if the
client is slow and can't really keep up with server i.e, substrate may
keep lots of message in memory

This PR changes the outgoing stream to abort and send a `Stop` event
downstream in the case that client doesn't keep up with the producer.

*In depth notes about how this PR should be integrated by downstream
projects. This part is mandatory, and should be
reviewed by reviewers, if the PR does NOT have the `R0-Silent` label. In
case of a `R0-Silent`, it can be ignored.*

- `rpc::Subscription::pipe_from_stream` - now takes `Self` param by
reference, change was made to allow sending events to the `Subscription`
after calls to `pipe_from_stream`.
- `chainhead_follow::submit_events` - now uses `Abortable` stream to end
it early in case
     - connection was closed by the client
     - signal received that subscription should stop
     - error has occured when processing the events
     - client can't keep up with the events produced
- TODO:
  - make the abort logic less hacky

---------

Co-authored-by: default avatarNiklas Adolfsson <[email protected]>
Co-authored-by: default avatarAlexandru Vasile <[email protected]>
(cherry picked from commit a0aefc6b

)
Signed-off-by: default avatarPavlo Khrystenko <[email protected]>
parent fc627930
Pipeline #502068 waiting for manual action with stages
in 1 hour, 17 minutes, and 17 seconds
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment