gzip compression using varnish cache - reverse-proxy

Question

Im trying to provide gzip compression using varnish cache. But when I set content-encoding as gzip using my below mentioned configuration for varnish (default.vcl). Browser failed to download those content for which i set content-encoding as gzipped.
Varnish configuration file:
backend default {
.host = "127.0.0.1";
.port = "9000";
}
backend socketIO {
.host = "127.0.0.1";
.port = "8083";
}
acl purge {
"127.0.0.1";
"192.168.15.0"/24;
}
sub vcl_fetch {
/* If the request is for pictures, javascript, css, etc */
if (req.url ~ "^/public/" || req.url ~ "\.js"){
unset req.http.cookie;
set beresp.http.Content-Encoding= "gzip";
set beresp.ttl = 86400s;
set beresp.http.Cache-Control = "public, max-age=3600";
/*set the expires time to response header*/
set beresp.http.expires=beresp.ttl;
/* marker for vcl_deliver to reset Age: */
set beresp.http.magicmarker = "1";
}
if (!beresp.cacheable) {
return (pass);
}
return (deliver);
}
sub vcl_deliver {
if (resp.http.magicmarker) {
/* Remove the magic marker */
unset resp.http.magicmarker;
/* By definition we have a fresh object */
set resp.http.age = "0";
}
if(obj.hits > 0) {
set resp.http.X-Varnish-Cache = "HIT";
}else {
set resp.http.X-Varnish-Cache = "MISS";
}
return (deliver);
}
sub vcl_recv {
if (req.http.x-forwarded-for) {
set req.http.X-Forwarded-For =
req.http.X-Forwarded-For ", " client.ip;
} else {
set req.http.X-Forwarded-For = client.ip;
}
if (req.request != "GET" &&
req.request != "HEAD" &&
req.request != "PUT" &&
req.request != "POST" &&
req.request != "TRACE" &&
req.request != "OPTIONS" &&
req.request != "DELETE") {
/* Non-RFC2616 or CONNECT which is weird. */
return (pipe);
}
# Pass requests that are not GET or HEAD
if (req.request != "GET" && req.request != "HEAD") {
return(pass);
}
#pipe websocket connections directly to Node.js
if (req.http.Upgrade ~ "(?i)websocket") {
set req.backend = socketIO;
return (pipe);
}
# Properly handle different encoding types
if (req.http.Accept-Encoding) {
if (req.url ~ "\.(jpg|png|gif|gz|tgz|bz2|tbz|mp3|ogg|js|css)$") {
# No point in compressing these
remove req.http.Accept-Encoding;
} elsif (req.http.Accept-Encoding ~ "gzip") {
set req.http.Accept-Encoding = "gzip";
} elsif (req.http.Accept-Encoding ~ "deflate") {
set req.http.Accept-Encoding = "deflate";
} else {
# unkown algorithm
remove req.http.Accept-Encoding;
}
}
# allow PURGE from localhost and 192.168.15...
if (req.request == "PURGE") {
if (!client.ip ~ purge) {
error 405 "Not allowed.";
}
return (lookup);
}
return (lookup);
}
sub vcl_hit {
if (req.request == "PURGE") {
purge_url(req.url);
error 200 "Purged.";
}
}
sub vcl_miss {
if (req.request == "PURGE") {
purge_url(req.url);
error 200 "Purged.";
}
}
sub vcl_pipe {
if (req.http.upgrade) {
set bereq.http.upgrade = req.http.upgrade;
}
}
Response Header:
Cache-Control:public, max-age=3600
Connection:keep-alive
Content-Encoding:gzip
Content-Length:11520
Content-Type:application/javascript
Date:Fri, 06 Apr 2012 04:53:41 GMT
ETag:"1330493670000--987570445"
Last-Modified:Wed, 29 Feb 2012 05:34:30 GMT
Server:Play! Framework;1.2.x-localbuild;dev
Via:1.1 varnish
X-Varnish:118464579 118464571
X-Varnish-Cache:HIT
age:0
expires:86400.000
Any suggestion on how to fix it and how to provide gzip compression using varnish.

Answer 1

Varnish Cache 3.0 does most of the handling of Accept-Encoding automatically and you shouldn't mess with it.
Basically, if you want Varnish to compress an object just set beresp.do_gzip in vcl_fetch and it will compress it before storing it in cache. Uncompression happens automatically when needed.

Answer 2

The content-length seems to be wrong, try un-setting it. Also, why are you using the beresp instead of obj in vcl_fetch?
...
obj.http.Content-Encoding="gzip";
remove obj.http.Content-Length;
...

Answer 3

Check and see if you are with apache, and have mod_deflate enabled,
try disabling it.