HTTP Chunked Transfer Question

[Nick Dunkin <Ni...@vecima.com>]

Hi,

I’m curious about people’s experiences with the chunked transfer options in traffic server.

proxy.config.http.chunking_enable


  1.  Is anyone using this feature to deliver low latency video segments for either HLS or DASH?
  2.  If the origin server also supports chunked transfer, does ATS deliver each “chunk” immediately on to the client, or does it wait until the whole payload has been received from the origin?

Thanks,

Nick

Nick Dunkin
Director, Software Engineering
Manager – Architecture and New Product Introduction
o:  +1 678.258.4071
e: nick.dunkin@vecima.com<ma...@vecima.com>

[cidimage001.png@01D6CC8C.6FC5A580]

Re: HTTP Chunked Transfer Question

[Miles Libbey <ml...@apache.org>]

We are very much not chunked fans.

Just filed
https://github.com/apache/trafficserver/issues/7544
today -- chunked encoding from the origin for relatively large files are
consistently stalling out for us.
and had several other problems over the last few years
https://github.com/apache/trafficserver/issues/7230
also had some corrupted objects get into place, so, anytime we use the
origin that frequently uses chunked encoding, we use this header_rewrite:
      cond %{SEND_RESPONSE_HDR_HOOK} [AND]
      cond %{STATUS} =200 [AND]
      cond %{HEADER:Transfer-Encoding} ="chunked" [OR]
      cond %{HEADER:Content-Length} =""
        set-header Cache-Control "no-store"
so that downstream caches only end up caching the objects sent with a
content-length.

And then chunked encoding goes away with http2...

And to answer specific questions:
- The low latency HLS spec avoided chunked encoding, so our expiraments
with it have not used chunked.
- When the origin sends chunked, ATS "streams" the response just like in
non-chunked encoding.
miles

On Fri, Feb 19, 2021 at 2:12 PM Nick Dunkin <Ni...@vecima.com> wrote:

> Hi,
>
>
>
> I’m curious about people’s experiences with the chunked transfer options
> in traffic server.
>
>
>
> *proxy.config.**http**.**chunking**_enable*
>
>
>
>    1. Is anyone using this feature to deliver low latency video segments
>    for either HLS or DASH?
>    2. If the origin server also supports chunked transfer, does ATS
>    deliver each “chunk” immediately on to the client, or does it wait until
>    the whole payload has been received from the origin?
>
>
>
> Thanks,
>
>
>
> Nick
>
>
>
> *Nick Dunkin*
>
> Director, Software Engineering
>
> Manager – Architecture and New Product Introduction
>
> *o: * *+1 678.258.4071*
>
> *e:* nick.dunkin@vecima.com
>
>
>
> [image: cidimage001.png@01D6CC8C.6FC5A580]
>