Content Encoding Error while returning data from memcached stored by ngx_srcache

n1xman nginx-forum at
Fri Mar 16 11:58:47 UTC 2012

I need little help here. First time browsing or memcached restart will
show you the data correctly; but when you refresh second time and it
will gives you content encoding error and I think it is something to do
with my nginx or ngx_srcache config for fetching data from memcached. I
checked using Wireshark from the client-end and found nginx sending
uncompressed data and I can see the Accept-encoding and
Connection-encoding on request and response header are set respectively.
I suspect the error triggers due to browser expect compressed data
instead of uncompressed data.

Backend I get uncompressed data and I assume that ngx_srcache will
compress said data before storing them on memcached. If ngx_srcache
compress data and store them in memcached by default, how do we pass
client accept encoding to memcached via ngx_srcache which is not
happening. If I use gzip off; then I get data properly.

Here are my configurations:

uname -a
Linux abmx-test 2.6.18-194.el5PAE #1 SMP Tue Mar 16 22:00:21 EDT 2010
i686 i686 i386 GNU/Linux

./nginx -V
nginx version: nginx/1.1.17
built by gcc 4.1.2 20080704 (Red Hat 4.1.2-48)
TLS SNI support disabled
configure arguments: --add-module=./contrib/echo-nginx-module-6c1f553
--add-module=./contrib/srcache-nginx-module-86e7a18 --with-debug
--with-http_ssl_module --with-http_realip_module
--with-http_addition_module --with-http_sub_module
--with-http_dav_module --with-http_mp4_module
--with-http_gzip_static_module --with-http_random_index_module
--with-http_secure_link_module --with-http_stub_status_module
--without-mail_pop3_module --without-mail_imap_module
--without-mail_smtp_module --with-mail_ssl_module

user  nginx;
worker_processes  1;

error_log  /usr/local/nginx/logs/error.log debug;
pid        /usr/local/nginx/logs/;

events {
    worker_connections  1024;

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local]
"$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    keepalive_timeout  65;
  gzip  on;
    gzip_static       on;
    gzip_buffers      16 8k;
    gzip_proxied      any;
    gzip_comp_level   8;
    gzip_http_version 1.1;
    gzip_min_length   512;
    gzip_types        text/plain text/css application/json
application/x-javascript application/xml application/xml+rss
text/javascript application/javascript text/x-js
application/x-shockwave-flash text/json;
    gzip_vary         on;

upstream my_mem {

server {
    listen       80;
    server_name  localhost;

    access_log /var/log/nginx/access.log main;
    error_log /var/log/nginx/error.log debug;

        default_type application/json;

location = /memc {

        memc_connect_timeout 100ms;
        memc_send_timeout 100ms;
        memc_read_timeout 100ms;

        set $memc_key $query_string;
        set $memc_exptime 30;
     #   set $memc_exptime $arg_exptime;

        memc_pass my_mem;

    location /mix2 {
        default_type  "application/json;charset=UTF-8";
        set $key $args;
        srcache_fetch GET /memc key=$key;
        srcache_store PUT /memc key=$key;
        srcache_store_statuses 200 301 302 404;
        srcache_response_cache_control off;

	# No data found in memcached
	   proxy_set_header Accept-Encoding "";


    location / {
        root   /usr/share/nginx/html;
        index  index.html index.htm;

    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /usr/share/nginx/html;


Error log when there is not data in memcached 

Error log when there is data in memcahced

Please advice.

Posted at Nginx Forum:,223951,223951#msg-223951

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