> On 31 Oct 2019, at 10:02, Christopher Faulet <cfau...@haproxy.com> wrote:
>
> Le 29/10/2019 à 18:48, Ing. Andrea Vettori a écrit :
>> Here is a direct session to backend server from the client machine in clear
>> text http2 without upgrade. Note that in this case output is NOT truncated
>> if I call the command without the ‘-n’ option. To do this test I temporary
>> overriden the host’s name dns resolution on the client (curl has a handy
>> option to do that but haven’t found it on nghttp).
> ...
>> The following is the same client to the haproxy server, to port 80 i.e. no
>> “proto h2” on the front-end. Proto h2 on the backend. Note that in this case
>> output is truncated if I call the command without the ‘-n’ option
> ...
>> Finally this is the output when port 82 is called on haproxy, i.e. the
>> frontend with “proto h2” option. This also produces truncated output.
>>
> ...
>
> Ok, Thanks for these infos. So, from the H2 point of view, the responses are
> valid and well formatted. But the responses size are radically different. If
> the size should be the same for all the three responses, the bug is probably
> in the communication between HAProxy and the server. Because the 2nd response
> is ~144K lower than the 1st one. And the 3rd is ~232K lower. So, far from the
> internal buffer size.
Yes, I also noticed that the connections that go through haproxy have data
packets with very different lengths while the direct connection seems a lot
more consistent with respect to size.
>
> To emit a flag END_STREAM on a DATA frame, internally, we need to reach the
> end of the HTTP message. It is marked by a dedicated block of data
> (HTX_BLK_EOM). This one is present if the flag END_STREAM was received on the
> other side.
Is it normal that the data frame with END_STREAM has zero length on haproxy
responses while it’s > 0 (1 actually) on the direct connection ?
>
> So now, the next move is to provide a network capture. Sorry to ask it again
> :) Because you use dedicated ports for your tests, I guess it will be quite
> simple. Could you provide the result of the following command, executed on
> HAProxy server ?
>
> tcpdump -i any -w h2toh2.cap port 82 or port 8080
>
> You can fill the capture with some requests on http://g.testhost.com:82. It
> could be also usefull to have the capture of a successfull request.
>
> Sorry to bother you with all these stuff. But for now, I don't know where to
> start my investigation.
Sure I’ll do as soon as possibile and thank you very much for your continued
support.
—
Ing. Andrea Vettori
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