# -*- ruby -*-
# vim: set noet nosta sw=4 ts=4 :
require 'arborist/monitor/snmp' unless defined?( Arborist::Monitor::SNMP )
# SNMP memory availability checks.
# Returns total available memory in Kb to the 'available_memory' attribute.
#
class Arborist::Monitor::SNMP::Memory
include Arborist::Monitor::SNMP
extend Loggability
log_to :arborist
# OIDS for discovering memory usage.
#
MEMORY = {
mem_avail: '1.3.6.1.4.1.2021.4.6.0'
}
# Global defaults for instances of this monitor
#
DEFAULT_OPTIONS = {
error_at: 95, # in percent full
}
### This monitor is complex enough to require creating an instance from the caller.
### Provide a friendlier error message the class was provided to exec() directly.
###
def self::run( nodes )
return new.run( nodes )
end
### Create a new instance of this monitor.
###
def initialize( options=DEFAULT_OPTIONS )
options = DEFAULT_OPTIONS.merge( options || {} )
options.each do |name, value|
self.public_send( "#{name.to_s}=", value )
end
end
# Set an error if memory used is below this many kilobytes.
attr_accessor :error_at
### Perform the monitoring checks.
###
def run( nodes )
super do |snmp, host|
self.gather_free_memory( snmp, host )
end
end
#########
protected
#########
### Collect available memory information for +host+ from an existing
### (and open) +snmp+ connection.
###
def gather_free_memory( snmp, host )
self.log.debug "Getting available memory for: %s" % [ host ]
mem_avail = snmp.get( SNMP::ObjectId.new( MEMORY[:mem_avail] ) ).varbind_list.first.value.to_f
self.log.debug " Available memory on %s: %0.2f" % [ host, mem_avail ]
config = @identifiers[ host ].last || {}
error_at = config['error_at'] || self.error_at
if mem_avail <= error_at
@results[ host ] = {
error: "Available memory is under %0.1fMB" % [ error_at.to_f / 1024 ],
available_memory: mem_avail
}
else
@results[ host ] = { available_memory: mem_avail }
end
end
end # class Arborist::Monitor::SNMP::Memory