# Arbiter Definition¶

## Description¶

The Arbiter object is a way to defined Arbiter daemons that will manage all the configuration and all the architecture of shinken like distributed monitoring and high availability. It reads the configuration, cuts it into parts (N schedulers = N parts), and then send them to all others elements. It manages the high availability part : if an element dies, it re-routes the configuration managed by this falling element to a spare one. Its other role is to receive input from users (like external commands of shinken.cmd) and send them to other elements. There can be only one active arbiter in the architecture.

The Arbiter definition is optionnal. If no arbiter is defined, Shinken will “create” one for the user. There will be no high availability for the Arbiter (no spare), and will use the default port in the server where the deamon is launched.

## Definition Format¶

Variables in red are required, while those in black are optional. However, you need to supply at least one optional variable in each definition for it to be of much use.

 define arbiter{ arbiter_name arbiter_name address dns name of ip address host_name hostname port port spare //[0/1]// modules modules
 timeout number of seconds to block the arbiter waiting for an answer data_timeout seconds to wait when sending data to another satellite(daemon) max_check_attempts number check_interval seconds to wait before issuing a new check }

## Example Definition:¶

define arbiter{
arbiter_name       Main-arbiter
host_name          node1
port               7770
spare              0
modules            module1,module2
}

## Variable Descriptions¶

arbiter_name

This variable is used to identify the short name of the arbiter which the data is associated with.

This directive is used to define the adress from where the main arbier can reach this arbiter (that can be itself). This can be a DNS name or a IP adress.

host_name

This variable is used by the arbiters daemons to define with ‘arbiter’ object they are : all theses daemons in differents servers use the same configuration, so the only difference is the serveur name. This value must be equal to the name of the server (like with the hostname command). If none is defined, the arbiter daemon will put the name of the server where it’s launched, but this will not be tolerated with more than one arbiter (because each daemons will think it’s the master).

port

This directive is used to define the TCP port used bu the daemon. The default value is 7770.

spare

This variable is used to define if the daemon matching this arbiter definition is a spare one of not. The default value is 0 (master).

modules

This variable is used to define all modules that the arbtier daemon matching this definition will load.

timeout

This variable defines how much time the arbiter will block waiting for the response of a inter-process ping (Pyro). 3 seconds by default. This operation will become non blocking when Python 2.4 and 2.5 is dropped in Shinken 1.4.

data_timeout

Data send timeout. When sending data to another process. 120 seconds by default.

max_check_attempts

If ping fails N or more, then the node is dead. 3 attempts by default.

check_interval

Ping node every N seconds. 60 seconds by default.