Galera Load Balancer

Galera Load Balancer (GLB) is a third-party tool produced by FromDual. Downloads and official documentation is available on their site: http://www.fromdual.com/. Similar to Galera, GLB only runs on Linux.

It consists of a daemon called glbd.

There is no client to manage GLB. To send administrative commands to GLB, for example to add or drop nodes, the generic nc tool can be used. The nc tool can communicate with a TCP daemon and print the reply on the screen, which is basically all we need to manage GLB. Here's the general syntax to send a command to glbd from the command line:

echo "<command>" | nc -q 1 <host_address> <port>

The host_address variable is the hostname or IP address, which glbd is running on, probably 127.0.0.1. The port variable is the port which glbd is listening to. There is no standard port; we have to specify it when we start the daemon.

The syntax to start glbd is as follows:

glbd [OPTIONS] <port> <node_list...