These are interesting results, thanks for investigating and sharing results!
I see that you have mostly been focusing on throughput in your posts, have you done testing for latency differences too? On Saturday, November 13, 2021 at 6:11:40 PM UTC-7 ren...@ix.netcom.com wrote: > As another data point, I decided to test a few implementations of http2 > downloads on OSX. > > Using a Go server with default frame size (16k): > > Go client: 900 MB/s > Java client: 1300 MB/s > curl: 1500 MB/s > > Using a Java server with default frame size (16k): > > Go client: 670 MB/s > Java client: 720 MB/s > curl: 800 M/s > > Using Go server using 256k client max frame size: > > Go client: 2350 MB/s > Java client: 2800 MB/s > h2load: 4300 MB/s > > Using Java server using 256k client max frame size: > > Go client: 2900 MB/s > Java client: 2800 MB/s > h2load: 3750 MB/s > > For h2load, I needed to create a PR to allow the frame size to be set, see > https://github.com/nghttp2/nghttp2/pull/1640 > > > On Nov 10, 2021, at 7:04 PM, robert engels <ren...@ix.netcom.com> wrote: > > 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. <xnow4f...@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 >> >> My CL 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> 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 >> wrote: >> >>> Well, I figured out a way to do it simply. The CL is here >>> 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 >>> 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> wrote: >>>> >>>> http/2 implementation seems ~5x slower in bytes per seconds (when >>>> transfer is cpu capped). >>>> >>>> POC: 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 ) 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. >>>> 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. >> >> 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...@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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