Requests are not concurrent with SPDY and proxy_cache modules

[Valentin V. Bartenev]

On Friday 26 June 2015 10:13:04 vgallissot wrote:
> Hi all, 
> 
> I'm experiencing a strange behaviour on my SPDY tests. 
> 
> I use nginx as a reverse proxy of a node.Js application. 
> 
> I enabled spdy module and proxy_cache (nginx.conf file bellow) and I
> actually see no difference in requests speed.

SPDY (and HTTP/2.0 as well) has no performance benefits for low-latency connections.


> Requests are well handed by
> SPDY protocol (one TCP connection and multiple streams catched with
> tcpdump), but they should be concurrent and they actually are sequentials
> like without SPDY support. 
> 
> Here are two screenshots of the waterfalls to see the behaviour
> 1) With proxy_cache support and SPDY not enabled : 
> https://lut.im/9QKXlT5T/LVFNWqxN
> 
> 2) With proxy_cache support and SPDY enabled : 
> https://lut.im/DmJ2wqFp/43ZOyhTE
> 
[..]

You're testing on loopback interface with about zero latency.  So nginx had time
and throughput to respond on the request before starting processing the next one,
since most of your resources are just a few kilobytes.

  wbr, Valentin V. Bartenev