Mediathek WRR

System setup

OS: Ubuntu 16.04

apt install nginx-extras
apt install lua-nginx-redis
apt install redis-server

NGINX configuration

Copy the mvlb.lua script from GitHub repo to a /var/www/ sub directory.

Configure NGINX site configuration (e.g. /etc/nginx/sites-enabled/default)

lua_package_path "/usr/share/lua/5.1/nginx/?.lua;;";
lua_socket_pool_size 100;
lua_socket_connect_timeout 10ms;
lua_socket_read_timeout 10ms;

server {
        ...
        location / {
                access_by_lua_file /var/www/srv1/mvlb.lua;
        }
        ...
}

Redis commands

Add new server

Add server URL

NOTE: Do not add a trailing slash to the URL!

$ redis-cli
127.0.0.1:6379> hset mdthk:vlb:servers srv5 "http://verteiler5.mediathekview.de"

NOTE: srv5 is the key and must be unique

Set server weight

$ redis-cli
127.0.0.1:6379> zadd mdthk:vlb:weights 4 srv5

Show all servers

URLs:

$ redis-cli
127.0.0.1:6379> hgetall mdthk:vlb:servers
 1) "srv1"
 2) "http://verteiler1.mediathekview.de"
 3) "srv2"
 4) "http://verteiler2.mediathekview.de"
 5) "srv3"
 6) "http://verteiler3.mediathekview.de"
 7) "srv4"
 8) "http://verteiler4.mediathekview.de"
 9) "srv5"
10) "http://verteiler5.mediathekview.de"

Weights:

$ redis-cli
127.0.0.1:6379> zrange mdthk:vlb:weights 0 -1 withscores
 1) "srv2"
 2) "2"
 3) "srv3"
 4) "2"
 5) "srv1"
 6) "4"
 7) "srv4"
 8) "4"
 9) "srv5"
10) "4"

Remove a server

NOTE: To disable a server temporary, it's enough to remove the corresponding weights entry as shown below. Later you can add the entry again.

Remove server weight entry:

$ redis-cli
127.0.0.1:6379> zrem mdthk:vlb:weights srv5

Remove the server URL:

$ redis-cli
127.0.0.1:6379> hdel mdthk:vlb:servers srv5

Get server hit counters

$ redis-cli
127.0.0.1:6379> zrange mdthk:vlb:hits 0 -1 withscores
 1) "srv3"
 2) "2"
 3) "srv2"
 4) "3"
 5) "srv1"
 6) "4"
 7) "srv4"
 8) "4"
 9) "srv5"
10) "4"