Hi Ray, Generally I agree that to lessen response times it is a good idea to have a > valid established connection ready before subsequent requests are made to > the same server
Sounds like we have agreement on the benefit of having this callback. However I think the option you are proposing is too niche and there would > not be a benefit for many users so I don't see the point in adding it. It > does not necessarily work well because as discussed curl must process the > GOAWAY and that is not guaranteed to happen immediately. I may have misunderstood, but there does not seem to be anything preventing cURL from handling the GOAWAY frame in this case. My proposal is to add a callback that signals the application when a GOAWAY frame is received (cURL still handles GOAWAY frame as-is). This may be a chicken-and-egg situation since we don't currently have such a callback in cURL, so the benefits are not yet clear. However, I believe that supporting this could be helpful for some use cases, including my own and the one described in issue #4839 that you previously referenced. If cURL implemented a GOAWAY callback, developers could respond appropriately on receipt of a GOAWAY, enabling graceful shutdown of HTTP/2 connections in their applications. Thanks, On Tue, Jan 9, 2024 at 11:40 AM Ray Satiro via curl-library < curl-library@lists.haxx.se> wrote: > On 1/7/2024 7:47 PM, Cao Duc Quan wrote: > > You are asking for a low level signal that almost nobody needs. It sounds >> like you are trying to work around a server or application issue. > > Agree my use case is quite odd but that is the protocol we developed for > years and I saw the benefit of having this low-level signal. Is there any > down-side to support this? > > > Generally I agree that to lessen response times it is a good idea to have > a valid established connection ready before subsequent requests are made to > the same server. However I think the option you are proposing is too niche > and there would not be a benefit for many users so I don't see the point in > adding it. It does not necessarily work well because as discussed curl must > process the GOAWAY and that is not guaranteed to happen immediately. > > curl could use improvement in connection upkeep, see the TODO. [1] There > is only curl_easy_upkeep [2] which will send HTTP/2 PING, but currently it > is only for easy handles that are not part of a multi (eg easy interface > was used curl_easy_perform and not curl_multi_perform) and do not have a > shared connection cache. I think it may be possible to change it to covered > shared connection caches, I will check. > > > [1]: https://curl.se/docs/todo.html#Monitor_connections_in_the_conne > [2]: https://curl.se/libcurl/c/curl_easy_upkeep.html > > -- > Unsubscribe: https://lists.haxx.se/mailman/listinfo/curl-library > Etiquette: https://curl.se/mail/etiquette.html > -- -------------------------------- Watson Cao VN: (+84) 0976574864 CA: (+1) 2368658864
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