Re: Unidirectional streams PR

[Kazuho Oku <[e-mail]>]

2017-07-07 10:05 GMT+09:00 Martin Thomson <[e-mail]>:
> On 7 July 2017 at 10:57, Kazuho Oku <[e-mail]> wrote:
>> Could somebody clarify what a server is expected to do when there are
>> no more streams than can be used to send a response (i.e. when a
>> server has used all the Stream IDs up to 2^32-2 and then receives a
>> request)?
>
> I think that the only sensible approach is to give up on the
> connection before this point is reached.
>
> A client can't know exactly how many streams a server has open, so I
> think that the only sensible course of action is to initiate graceful
> shutdown whenever the endpoint might be inclined to MAX_STREAM_ID that
> is 2^32-1 or greater.
>
> (In the PR, the limit is 2^32-1.)

Thank you for the clarification.

So it would be sensible to stop initiating new requests on an existing
connection when the number of unused stream IDs of the peer becomes as
low as max-concurrent-streams multiplied by some safety factor
(something like 10 would be enough, considering the probability of
loss or reordering of packets carrying DATA frames and consecutive
MAX_STREAM_ID frames).

-- 
Kazuho Oku