Your CL works well with the POC. Side question not specific to this issue: how to test changes to golang.org/x/net with net/http ? The 'h2_bundle' trick with go generate & bundle requires to fork the std lib too ? I have a hard time figuring how to do this. I tried with gotip but I get an error with "gotip generate" (bundle: internal error: package "strings" without types was imported from "golang.org/x/net/http2") Any doc/tutorial on how to deal with this 'bundle' trick ?
thx Le lundi 15 novembre 2021 à 17:32:48 UTC+1, ren...@ix.netcom.com a écrit : > Since http2 multiplexes streams it will delicately affect latency on other > streams. This is why I suggested using multiple transports - one for high > throughput transfers and another for lower latency “interactive” sessions. > > On Nov 15, 2021, at 9:23 AM, Kevin Chowski <ke...@chowski.com> wrote: > > 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. > 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/3138434b-d480-4473-8b20-2598412a0eden%40googlegroups.com > > <https://groups.google.com/d/msgid/golang-nuts/3138434b-d480-4473-8b20-2598412a0eden%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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