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This article mainly explains "geo module in Nginx and how to use it to configure load balancing". Interested friends may wish to have a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn "the geo module in Nginx and how to configure load balancing with it".

The geo instruction is provided by the ngx_http_geo_module module. By default, nginx loads this module unless it is artificially-- without-http_geo_module.

The ngx_http_geo_module module can be used to create variables whose values depend on the client ip address.

Geo instruction

Syntax: geo [$address] $variable {...}

Default value:-

Configuration segment: http

Defines to get the ip address of the client from the specified variable. By default, nginx gets the client ip address from the $remote_addr variable, but it can also be obtained from other variables. Such as

Geo $remote_addr $geo {default 0; 127.0.0.1;} geo $arg_ttlsa_com $geo {default 0; 127.0.0.1;}

If the value of this variable does not represent a valid ip address, then nginx will use the address "255.255.255.255".

Nginx describes the address by cidr or address field, and supports the following parameters:

Delete: deletes the specified network

Default: if the client address does not match any of the defined addresses, nginx will use this value. If you use cidr, you can use "0. 0. 0. 0. 0. 0" instead of default.

Include: contains a file that defines addresses and values, and can contain multiple.

Proxy: defines a trusted address. If the request comes from a trusted address, nginx uses its "x-forwarded-for" header to obtain the address. Compared to ordinary addresses, trusted addresses are detected sequentially.

Proxy_recursive: enable recursive lookup address. If recursive lookup is turned off, nginx uses the last address in "x-forwarded-for" instead of the original client address when the client address matches a trusted address. If recursive lookup is enabled, when the client address matches a trusted address, nginx replaces the original client address with the last address in "x-forwarded-for" that does not match all trusted addresses.

Ranges: use to define an address in the form of an address field, and this parameter must be placed first. To speed up the loading of the address library, addresses should be defined in ascending order.

Geo $country {default zz; include conf/geo.conf; delete 127.0.0.0 ru; 16; proxy 192.168.100.0 vim conf/geo.conf10.2.0.0/16 ru 24; proxy 2001 Vera 0db8 Groupe Maple 32; 127.0.0.0 vim conf/geo.conf10.2.0.0/16 ru 24 ru; 127.0.0.1 vim conf/geo.conf10.2.0.0/16 ru 32 ru; 10.1.0.0 vim conf/geo.conf10.2.0.0/16 ru 192.168.2.0/24 ru

Example of address field:

Geo $country {ranges; default zz; 127.0.0.0-127.0.0.0 us; 127.0.0.1-127.0.0.1 ru; 127.0.0.1-127.0.255 us; 10.1.0.0-10.1.255.255 ru; 192.168.1.0-192.168.1.255 uk;}

The geo instruction mainly assigns values to variables according to ip. Therefore, only ip or network segment can be defined under the geo block, otherwise an error will be reported.

Global load balancing based on geo module

Server1: 192.168.6.101

Server2: 192.168.6.102

Server3: 192.168.6.121

Test machine 1 ip:192.168.6.2

Test machine 2 ip:192.168.6.8

Test machine 3 ip:192.168.6.189

1. Compile and install nginx on every server, so I won't say much!

Server1, I have not changed the configuration of server2 ~ just change his home page, which is good for testing!

Server1:

Shell $> cd / usr/local/nginx/htmlshell $> rm index.htmlshell $> echo "192.168.6.101" > index.html

Server2:

Shell $> cd / usr/local/nginx/htmlshell $> rm index.htmlshell $> echo "192.168.6.102" > index.html

Get all their services up.

Shell $> / usr/local/nginx/sbin/nginx

two。 Modify the configuration of server3 `

Shell $> cd / usr/local/nginx/conf/shell $> vim nginx.confworker_processes 1; events {worker_connections 1024;} http {include mime.types; default_type application/octet-stream; geo $geo {default default; 192.168.6.189 default default; 32 uk; 192.168.6.8 us # the subnet code here is 32 because I am a single network segment test. If you have vlan, you can be 24, such as # 192.168.0 tw 24 tw} upstream uk.server {server 192.168.6.101;} upstream us.server {server 192.168.6.102;} upstream default.server {server 192.168.6.121j8080;} sendfile on; keepalive_timeout 65; server {listen 80 Server_name 192.168.6.121; index index.html index.htm; root html; location / {proxy_redirect off; proxy_set_header host $host; proxy_set_header x-real-ip $remote_addr; proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for; proxy_pass http://$geo.server$request_uri;} error_page 500502 503 504 / 50x.html Location = / 50x.html {root html;}} server {listen 8080; server_name 192.168.6.121; location / {root html; index index.html index.htm;}

3. Test, open the browser input on test machine 1

Http://192.168.6.121

Display

Because the test machine 1 ip address is 192.168.6.2 according to the nginx configuration, it is obvious that he is accessing port server3 8080! I modified it because of server1 server2's index.html.

Open the browser on test machine 2 ~ enter

Http://192.168.6.121

Display

Open a browser on test machine 3 ~ enter

Http://192.168.6.121

The test machine 3 ip is 192.168.6.189.

Display:

Obviously, load balancing has played a role.

In this way, you can put the three servers in different idc rooms. Then you can do it in data synchronization ~ the advantage of this is that you don't have to tamper with the dns, because the intelligent dns sometimes parses the other party's dns address according to the visiting ip, matching him to a server. If the other party is a Netcom user, he uses the telecom dns, which will directly match him to the telecom server, nginx, to access the ip to match the server. In this way, as long as we collect the ip segments of each region, it will be fine.

At this point, I believe you have a deeper understanding of the "geo module in Nginx and how to use it to configure load balancing". You might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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