# Requests are not concurrent with SPDY and proxy\_cache modules

**URL:** <https://www.ruby-forum.com/t/requests-are-not-concurrent-with-spdy-and-proxy-cache-modules/242480>\
**Category:** NGINX\
**Created:** [June 26, 2015, 4:13pm UTC](https://www.ruby-forum.com/t/requests-are-not-concurrent-with-spdy-and-proxy-cache-modules/242480 "2015-06-26T16:13:47Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Detlef\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58f4c7/32.png) [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\
**Post date:** [June 26, 2015, 4:13pm UTC](https://www.ruby-forum.com/t/requests-are-not-concurrent-with-spdy-and-proxy-cache-modules/242480/1 "2015-06-26T16:13:47Z")

</div>

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. 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](https://lut.im/9QKXlT5T/LVFNWqxN)

2. With proxy\_cache support and SPDY enabled :  
[https://lut.im/DmJ2wqFp/43ZOyhTE](https://lut.im/DmJ2wqFp/43ZOyhTE)

Here is the configuration file I use to test on my laptop :  
8------------------------------------------------------------------------------------------------------------------------------------\>  
…  
####### tests SPDY  
keepalive\_requests 1000;  
keepalive\_timeout 10;

```
client_body_timeout 10;
client_header_timeout 10;
types_hash_max_size 2048;

server_tokens off;

server_names_hash_bucket_size 128;
server_name_in_redirect off;

proxy_http_version 1.1;

fastcgi_buffers 256 4k;

gzip_static on;
gzip_disable "MSIE [1-6]\.(?!.*SV1)";
gzip_vary on;
gzip_http_version 1.1;

ssl_session_timeout 5m;
ssl_session_cache shared:SSL:20m;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_ciphers

```

‘ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128:AES256:AES:DES-CBC3-SHA:HIGH:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK’;  
ssl\_prefer\_server\_ciphers on;  
ssl\_ecdh\_curve secp384r1;  
ssl\_dhparam /etc/nginx/ssl/dhparam.pem;

```
upstream node_servers {
    keepalive 64;
    server node-server1;
    server node-server2;
}

# cache options
proxy_buffering on;
proxy_cache_path /etc/nginx/cache/ levels=1:1:2 keys_zone=nodes:256m

```

inactive=2048m max\_size=4096m;  
proxy\_ignore\_client\_abort off;  
proxy\_intercept\_errors on;  
proxy\_ignore\_headers X-Accel-Expires Expires Cache-Control;

```
proxy_cache_methods GET;
spdy_keepalive_timeout 10s; # inactivity timeout after which the 

```

SPDY  
connection is closed  
spdy\_recv\_timeout 4s; # timeout if nginx is currently  
expecting  
data from the client but nothing arrives  
server {  
listen 127.0.0.1:443 ssl spdy;  
listen [::1]:443 ssl spdy;

```
    server_name beta.mydomain.com;

    ssl_certificate /etc/nginx/ssl/cert.pem;
    ssl_certificate_key /etc/nginx/ssl/key.pem;

    add_header Alternate-Protocol "443:npn-spdy/3.1";
    location / {
        proxy_set_header Host $http_host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_redirect off;
        proxy_pass http://node_servers;
        proxy_cache nodes;
        proxy_cache_valid any 1h;
        proxy_cache_min_uses 10;
        add_header X-Nginx-Cached $upstream_cache_status;
    }
}

```

…  
\<------------------------------------------------------------------------------------------------------------------------------------8

More infos : nginx-1.8.0-4.fc22.x86\_64

So my question is : can those two modules work together or am I missing  
something in the conf ?

Thank you

Posted at Nginx Forum:

> **[Requests are not concurrent with SPDY and proxy\_cache modules](https://forum.nginx.org/read.php?2,259906,259906#msg-259906)**
>
> 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. Requests are...

---

<div class="post-metadata">

**Author:** ![vgallissot](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/9e8a1a/32.png) [@vgallissot](https://www.ruby-forum.com/u/vgallissot)\
**Post date:** [June 26, 2015, 5:03pm UTC](https://www.ruby-forum.com/t/requests-are-not-concurrent-with-spdy-and-proxy-cache-modules/242480/2 "2015-06-26T17:03:26Z")

</div>

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.

> [https://lut.im/DmJ2wqFp/43ZOyhTE](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