Serving Static Content

Overview on `root` directive

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- specifies directory to search for files (similar to DocumentRoot in apache)

- can be placed within level of http, server, or location contexts

server {

    root /www/data;

      # determines root directory for the 1st 2 locations

    location / {

    }

    location /images/ {

    }

    location ~ \.(mp3|mp4) {

        root /www/media;

          # this location specifies its own root directory

    }

}

Using index files

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- if requested URI ends with `/` such as http://webserver.com/images/, nginx

  treats the request as a request for directory and tries to look for an index

  file

- `index` directive determines the filename of the index file

  (default: index.html)

- if nginx cannot see an index file, it returns "HTTP Code 404"

prevents returning HTTP code 404 (if file is not found) and return a directory listing instead	location /images/ {     autoindex on; }
lists more than 1 filename for index file (searches them in order)	location / {     index index.$geo.html index.htm index.html;       # `$geo` value depends on client's address }
if index.html is not found but index.php is there, the request will be proxied	location / {     root /data;     index index.html index.php; } location ~ \.php {     fastcgi_pass localhost:8000;     ... }

Trying Several Options

----------------------

- this done by using `try_files` directive

serves default.gif if the file requested by URI is not found	server {     root /www/data;     location /images/ {         try_files $uri /images/default.gif;     } }
returns an error code if any of the given options doesn't resolve the issue	location / {     try_files $uri $uri/ $uri.html =404; }
redirect you to a backend server when the requested file is not found	location / {     try_files $uri $uri/ @backend; } location @backend {     proxy_pass http://backend.example.com; }

Optimizing Speed for Static Content

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Enabling sendfile  - nginx handles file transmission itself  - by default, it copies file into buffer    before sending  - enabling sendfile prevents buffering  - sendfile enables direct copying from    one file descriptor to another	location /mp3 {     sendfile           on;       # enables sendfile     sendfile_max_chunk 1m;       # limits file size handled by sendfile     ... }
Enabling tcp_nopush  - enables nginx to send HTTP response    headers in one packet right after the    chunk of data has been obtained by    sendfile	location /mp3 {     sendfile   on;     tcp_nopush on;     ... }
Enabling tcp_nodelay  - this disables Nagle's algorithm  - Nagle's algorithm are for slow    connections only; consolidates a    number of small packets into a larger    one and sends it in 200ms delay  - by default, `tcp_nodelay` is set to on    meaning Nagle's algorithm is disabled	location /mp3  {     tcp_nodelay       on;     keepalive_timeout 65;     ... }
Optimizing backlog queue  - general rule is when a connection is    established, it is put into "listen"    queue of a listen socket	to measure current listen queue: netstat -Lan example output: Current listen queue sizes (qlen/incqlen/maxqlen) Listen         Local Address         0/0/128        *.12345            10/0/128        *.80       0/0/128        *.8080 output above tells us that there is 10 unaccepted connections while having a maximum connection limit of 128 if the output is like this: Current listen queue sizes (qlen/incqlen/maxqlen) Listen         Local Address         0/0/128        *.12345            192/0/128        *.80       0/0/128        *.8080 the unaccepted connection is greater than the limit which is common when the website is experiencing heavy traffic to increase the limit on OS side: echo 'net.core.somaxconn = 4096' > /etc/sysctl.conf sysctl -p then increase the limit on Nginx side afterwards: server {     listen 80 backlog 4096;     # reload nginx after this change  ... }