No worries. I updated the issue and the CL. I will comment in the CL with a few more details.
> On Nov 10, 2021, at 2:30 PM, Andrey T. <xnow4fippy...@sneakemail.com> wrote: > > Thank you Robert, > I somehow missed the reference to the ticket in the first message, sorry > about that. > > As for the CL - I think adding link to the github issue, and add a bit of > explanation in a commit message would help. > I added link to your CL to the github issue's discussion, hopefully it will > bring more attention to it. > > A. > > On Wednesday, November 10, 2021 at 1:22:42 PM UTC-7 ren...@ix.netcom.com > wrote: > As reported in the OP, the issue was filed long ago > https://github.com/golang/go/issues/47840 > <https://github.com/golang/go/issues/47840> > > My CL https://go-review.googlesource.com/c/net/+/362834 > <https://go-review.googlesource.com/c/net/+/362834> is a viable fix (and > should of been supported originally). > > >> On Nov 10, 2021, at 12:59 PM, Andrey T. <xnow4f...@sneakemail.com >> <applewebdata://13B131F9-B302-4B65-8230-FBAD3381F1E0>> wrote: >> > >> Fellas, >> I would say the 5x throughput difference is a serious problem.Would you be >> kind and open an issue on github about it? >> Also, the PR that you have might benefit from explanation about what you are >> trying to solve (and probably link to an issue on github), so it would get >> more attention. >> >> Thanks! >> >> Andrey >> >> >> On Tuesday, November 9, 2021 at 4:50:34 PM UTC-7 ren...@ix.netcom.com >> <http://ix.netcom.com/> wrote: >> Well, I figured out a way to do it simply. The CL is here >> https://go-review.googlesource.com/c/net/+/362834 >> <https://go-review.googlesource.com/c/net/+/362834> >> >> The frame size will be used for all connections using that transport, so it >> is probably better to create a transport specifically for the >> high-throughput transfers. >> >> You can also create perform single shot requests like: >> >> if useH2C { >> rt = &http2.Transport{ >> AllowHTTP: true, >> DialTLS: func(network, addr string, cfg *tls.Config) (net.Conn, error) >> { >> return dialer.Dial(network, addr) >> }, >> MaxFrameSize: 1024*256, >> } >> } >> >> var body io.ReadCloser = http.NoBody >> >> req, err := http.NewRequestWithContext(ctx, "GET", url, body) >> if err != nil { >> return err >> } >> >> resp, err := rt.RoundTrip(req) >> >> >>> On Nov 9, 2021, at 3:31 PM, Robert Engels <ren...@ix.netcom.com <>> wrote: >>> >>> To be clear, I have no plans to submit a Cl to improve this at this time. >>> >>> It would require some api changes to implement properly. >>> >>>> On Nov 9, 2021, at 12:19 PM, Kirth Gersen <kirth...@gmail.com <>> wrote: >>>> >>>> Great ! >>>> >>>> > I made some local mods to the net library, increasing the frame size to >>>> > 256k, and the http2 performance went from 8Gbps to 38Gbps. >>>> That is already enormous for us. thx for finding this. >>>> >>>> 4 -> Indeed a lot of WINDOW_UPDATE messages are visible when using >>>> GODEBUG=http2debug=1 >>>> >>>> >>>> On Tuesday, November 9, 2021 at 6:28:16 PM UTC+1 ren...@ix.netcom.com >>>> <http://ix.netcom.com/> wrote: >>>> I did a review of the codebase. >>>> >>>> Http2 is a multiplexed protocol with independent streams. The Go >>>> implementation uses a common reader thread/routine to read all of the >>>> connection content, and then demuxes the streams and passes the data via >>>> pipes to the stream readers. This multithreaded nature requires the use of >>>> locks to coordinate. By managing the window size, the connection reader >>>> should never block writing to a steam buffer - but a stream reader may >>>> stall waiting for data to arrive - get descheduled - only to be quickly >>>> rescheduled when reader places more data in the buffer - which is >>>> inefficient. >>>> >>>> Out of the box on my machine, http1 is about 37 Gbps, and http2 is about 7 >>>> Gbps on my system. >>>> >>>> Some things that jump out: >>>> >>>> 1. The chunk size is too small. Using 1MB pushed http1 from 37 Gbs to 50 >>>> Gbps, and http2 to 8 Gbps. >>>> >>>> 2. The default buffer in io.Copy() is too small. Use io.CopyBuffer() with >>>> a larger buffer - I changed to 4MB. This pushed http1 to 55 Gbs, and http2 >>>> to 8.2. Not a big difference but needed for later. >>>> >>>> 3. The http2 receiver frame size of 16k is way too small. There is >>>> overhead on every frame - the most costly is updating the window. >>>> >>>> I made some local mods to the net library, increasing the frame size to >>>> 256k, and the http2 performance went from 8Gbps to 38Gbps. >>>> >>>> 4. I haven’t tracked it down yet, but I don’t think the window size update >>>> code is not working as intended - it seems to be sending window updates >>>> (which are expensive due to locks) far too frequently. I think this is the >>>> area that could use the most improvement - using some heuristics there is >>>> the possibility to detect the sender rate, and adjust the refresh rate >>>> (using high/low water marks). >>>> >>>> 5. The implementation might need improvements using lock-free structures, >>>> atomic counters, and busy-waits in order to achieve maximum performance. >>>> >>>> So 38Gbps for http2 vs 55 Gbps for http1. Better but still not great. >>>> Still, with some minor changes, the net package could allow setting of a >>>> large frame size on a per stream basis - which would enable much higher >>>> throughput. The gRPC library allows this. >>>> >>>> >>>>> On Nov 8, 2021, at 10:58 AM, Kirth Gersen <kirth...@ <>gmail.com >>>>> <http://gmail.com/>> wrote: >>>>> >>>> >>>>> http/2 implementation seems ~5x slower in bytes per seconds (when >>>>> transfer is cpu capped). >>>>> >>>>> POC: https://github.com/nspeed-app/http2issue >>>>> <https://github.com/nspeed-app/http2issue> >>>>> >>>>> I submitted an issue about this 3 months ago in the Go Github ( >>>>> https://github.com/golang/go/issues/47840 >>>>> <https://github.com/golang/go/issues/47840> ) but first commenter >>>>> misunderstood it and it got buried (they're probably just swamped with >>>>> too many open issues (5k+...)). >>>>> >>>>> Everything using Golang net/http is impacted, the Caddy web server for >>>>> instance. >>>>> >>>>> I know it probably doesn't matter for most use cases because it's only >>>>> noticeable with high throughput transfers (>1 Gbps). >>>>> Most http benchmarks focus on "requests per second" and not "bits per >>>>> seconds" but this performance matters too sometimes. >>>>> >>>>> If anyone with expertise in profiling Go code and good knowledge of the >>>>> net/http lib internal could take a look. It would be nice to optimize it >>>>> or at least have an explanation. >>>>> >>>>> thx (sorry if wrong group to post this). >>>>> >>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google Groups >>>>> "golang-nuts" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send an >>>>> email to golang-nuts...@ <>googlegroups.com <http://googlegroups.com/>. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/golang-nuts/89926c2f-ec73-43ad-be49-a8bc76a18345n%40googlegroups.com >>>>> >>>>> <https://groups.google.com/d/msgid/golang-nuts/89926c2f-ec73-43ad-be49-a8bc76a18345n%40googlegroups.com?utm_medium=email&utm_source=footer>. >>>> >>>> >>>> -- >>>> You received this message because you are subscribed to the Google Groups >>>> "golang-nuts" group. >>>> To unsubscribe from this group and stop receiving emails from it, send an >>>> email to golang-nuts...@googlegroups.com <>. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/golang-nuts/7332f727-6716-4c4d-85c5-a86cacd0c89fn%40googlegroups.com >>>> >>>> <https://groups.google.com/d/msgid/golang-nuts/7332f727-6716-4c4d-85c5-a86cacd0c89fn%40googlegroups.com?utm_medium=email&utm_source=footer>. >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "golang-nuts" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to golang-nuts...@googlegroups.com >> <applewebdata://13B131F9-B302-4B65-8230-FBAD3381F1E0>. > >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/golang-nuts/1bfe6aec-abd2-4f63-bf77-bbfa6fd213ban%40googlegroups.com >> >> <https://groups.google.com/d/msgid/golang-nuts/1bfe6aec-abd2-4f63-bf77-bbfa6fd213ban%40googlegroups.com?utm_medium=email&utm_source=footer>. > > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com > <mailto:golang-nuts+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/golang-nuts/1b63863b-45af-45d0-a885-8716acc65ac7n%40googlegroups.com > > <https://groups.google.com/d/msgid/golang-nuts/1b63863b-45af-45d0-a885-8716acc65ac7n%40googlegroups.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. 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