2009/03/09 21:23:19 [warn] 26827#0: 4096 worker_connections are more than open file resource limit: 1024

A solution is to use the command ulimit in nginx start script, just before lunching nginx:

[...]
ulimit  -n 65536
[...]

Some Content Delivery Network providers

• Akamaï
  • Akamaï on Crunchbase
• BitGravity
  • BitGravity on Crunchbase
• EdgeCast Networks
  • EdgeCast Networks on Crunchbase
• Limelight Network
  
  • Limelight Network on Crunchbase
• Panther Express
  • Panther Express on Crunchbase

# nginx -t
2008/11/13 09:37:03 [emerg] 12299#0: could not build the server_names_hash, you should increase server_names_hash_bucket_size: 32
2008/11/13 09:37:03 [emerg] 12299#0: the configuration file /etc/nginx/nginx.conf test failed

server_names_hash_bucket_size controls the maximum length of a virtual host entry (ie the length of the domain name).

In other words, if your domain names are long, increase this parameter.

You need to add this flag in the http context:

http {
    server_names_hash_bucket_size 64;
    ...
}

After increasing the value, test your configuration file and reload nginx:

# nginx -t
2008/11/13 09:48:06 [info] 12315#0: the configuration file /etc/nginx/nginx.conf syntax is ok
2008/11/13 09:48:06 [info] 12315#0: the configuration file /etc/nginx/nginx.conf was tested successfully
# kill -HUP `cat /var/run/nginx.pid`

This code indicates that “the server is currently unable to handle the request due to a temporary overloading or maintenance of the server”.

The 503 code is used to avoid crawlers or caching proxy use the maintenance page as the new valid content for the request. You certainly don’t want Google save this content in his search index as the content of your website

To achieve this we will use a rewrite rule in lighttpd to redirect all requests to a single PHP script which will return a 503 error code and print an informative message.

Lighttpd configuration

url.rewrite = ( "" => "/maintenance.php" )

This configuration will redirect any request to maintenance.php script.

If you need to serve an image in your maintenance page, you have to add another rule to the rewrite process like that :

url.rewrite = ( "upgrading.png" => "$0",
                "" => "/maintenance.php" )

Let some users see the website

It might be usefull to let admins or developers access the website during the maintenance.
For that, you can disable the maintenance rewrite rule for certain IP addresses :

 $HTTP["remoteip"] != “192.168.1.42″ {
               url.rewrite = ( "upgrading.png" => "$0",
                      "" => "/maintenance.php" )
}

PHP code example

<?php
header("HTTP/1.1 503 Service Unavailable");
?>
We're currently upgrading our servers...

Links

• RFC 2616 HTTP/1.1
• HTTP status codes on Wikipedia

$HTTP[”host”] =~ “^lescampeurs\.org” {
    url.redirect = (
        ”^/(.*)$” => “http://www.lescampeurs.org/$1″
    )
}

Links:

• Lighttpd mod_redirect
• HTTP 3xx status codes

Here is how to configure Apache to send log entries to cronolog :

CustomLog "|/usr/sbin/cronolog /home/log/apache2/%Y-%m-%d_domain.com_access.log" combined

This will create a log file named 2008-06-02_domain.com_access.log for today.

Cronolog reads log entries from standard input and writes them to the output file specified by your template.

More examples

• Rotate by month :

CustomLog "|/usr/sbin/cronolog /home/log/apache2/%Y-%m_domain.com_access.log" combined

• Rotate by week number :

CustomLog "|/usr/sbin/cronolog /home/log/apache2/%Y-%W_domain.com_access.log" combined

• Rotate hourly

CustomLog "|/usr/sbin/cronolog /home/log/apache2/%H_domain.com_access.log" combined

Links

• All cronolog templating flags
• Apache 2 mod_log_config documentation

With Apache2

    <DirectoryMatch "^/.*/\.svn/">
            Order allow,deny
            Deny from all
    </DirectoryMatch>

With lighttpd

    $HTTP["url"] =~ "/\.svn/" {
        url.access-deny = ( "" )
    }

server.modules += ( "mod_redirect" )

Force your domain with www.

$HTTP["host"] =~ "^domain\.com$" {
    url.redirect = ( "^/(.*)" => "http://www.domain.com/$1" )
}

Force your domain without www.

$HTTP["host"] =~ "^www\.domain\.com$" {
    url.redirect = ( "^/(.*)" => "http://domain.com/$1" )
}

Redirect HTTP requests to HTTPS

$SERVER["socket"] == ":80" {
    $HTTP["host"] =~ "(.*)" {
        url.redirect = ( "^/(.*)" => "https://%1/$1" )
    }
}

Redirect an old domain to your new domain

$HTTP["host"] =~ "^www1\.domain\.com" {
    url.redirect = ( "^/(.*)" => "http://www.domain.com/$1" )
}

Redirect a url that can be matched by a mod_rewrite rule

Lets say that you want to redirect http://www.domain.com/party to http://blog.domain.com/party while you have a mod_rewrite rule on www.domain.com that redirect all URLs to a controller (“^(.*)$” => “/index.php$1″).

Your redirect will not work because mod_rewrite always execute before redirect rules. To bypass this, you need to use the $0 as the rule target to pass URLs through unmangled.

e.g.

url.redirect = ( "^/party(.*)" => "http://blog.domain.com/party$1" )
url.rewrite-once = ( "^/party" => "$0" )

tested with lighttpd 1.4.x