Bump patch version.
# -*- ruby -*-
# vim: set noet nosta sw=4 ts=4 :
require 'arborist/monitor/snmp' unless defined?( Arborist::Monitor::SNMP )
# Machine load/cpu checks.
#
# Sets current 1, 5, and 15 minute loads under the 'load' attribute,
# and calculates/warns on cpu overutilization.
#
class Arborist::Monitor::SNMP::CPU
include Arborist::Monitor::SNMP
extend Configurability, Loggability
log_to :arborist_snmp
# OIDS for discovering system load.
#
OIDS = {
load: '1.3.6.1.4.1.2021.10.1.3',
cpu: '1.3.6.1.2.1.25.3.3.1.2'
}
# When walking load OIDS, the iterator count matches
# these labels.
#
LOADKEYS = %i[ load1 load5 load15 ]
# Global defaults for instances of this monitor
#
configurability( 'arborist.snmp.cpu' ) do
# What overutilization percentage qualifies as a warning
setting :warn_at, default: 80
end
### Return the properties used by this monitor.
###
def self::node_properties
return USED_PROPERTIES
end
### Class #run creates a new instance and immediately runs it.
###
def self::run( nodes )
return new.run( nodes )
end
### Perform the monitoring checks.
###
def run( nodes )
super do |host, snmp|
self.find_load( host, snmp )
end
end
#########
protected
#########
### Find load data, add additional niceties for reporting.
###
def format_load( snmp )
info = { cpu: {}, load: {} }
cpus = snmp.walk( oid: OIDS[:cpu] ).each_with_object( [] ) do |(_, value), acc|
acc << value
end
info[ :cpu ][ :count ] = cpus.size
# Windows SNMP doesn't have a concept of "load" over time,
# so we have to just use the current averaged CPU usage.
#
# This means that windows machines will very likely want to
# adjust the default "overutilization" number, considering
# it's really just how much of the CPU is used at the time of
# the monitor run, along with liberal use of the Observer "only
# alert after X events" pragmas.
#
if self.system =~ /windows\s+/i
info[ :cpu ][ :usage ] = cpus.inject( :+ ).to_f / cpus.size
info[ :message ] = "System is %0.1f%% in use." % [ info[ :cpu ][ :usage ] ]
# UCDavis stuff is better for alerting only after there has been
# an extended load event. Use the 5 minute average to avoid
# state changes on transient spikes.
#
else
snmp.walk( oid: OIDS[:load] ).each_with_index do |(_, value), idx|
next unless LOADKEYS[ idx ]
info[ :load ][ LOADKEYS[idx] ] = value.to_f
end
percentage = (( ( info[:load][ :load5 ] / cpus.size) - 1 ) * 100 ).round( 1 )
if percentage < 0
info[ :message ] = "System is %0.1f%% idle." % [ percentage.abs ]
info[ :cpu ][ :usage ] = percentage + 100
else
info[ :message ] = "System is %0.1f%% overloaded." % [ percentage ]
info[ :cpu ][ :usage ] = percentage
end
end
return info
end
### Collect the load information for +host+ from an existing
### (and open) +snmp+ connection.
###
def find_load( host, snmp )
info = self.format_load( snmp )
config = identifiers[ host ].last || {}
warn_at = config[ 'warn_at' ] || self.class.warn_at
usage = info.dig( :cpu, :usage ) || 0
if usage >= warn_at
info[ :warning ] = "%0.1f utilization exceeds %0.1f percent" % [ usage, warn_at ]
end
self.results[ host ] = info
end
end # class Arborist::Monitor::SNMP::CPU