Module: CloudFlock::App::Watchdogs

Extended by:
Watchdogs
Included in:
Watchdogs
Defined in:
lib/cloudflock/app/common/watchdogs.rb

Overview

Public: The Watchdogs module provides commonly used watchdogs.

Instance Method Summary collapse

Instance Method Details

#set_alarm_system_load(watchdog, thread) ⇒ Object

Public: Set up a default alert for if the system load is >10, killing a given thread if it reaches that threshhold.

watchdog - Watchdog to which the alarm should be added. thread - Thread to kill if the alarm fires.

Returns nothing.



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# File 'lib/cloudflock/app/common/watchdogs.rb', line 72

def set_alarm_system_load(watchdog, thread)
  watchdog.create_alarm('load_too_high') { |waitq| waitq > 10 }
  watchdog.on_alarm('load_too_high')     { |waitq| thread.kill }
end

#set_alarm_used_space(watchdog, thread) ⇒ Object

Public: Set up a default alert for if free space on the host falls below 5%, killing a given thread if it reaches that threshhold.

watchdog - Watchdog to which the alarm should be added. thread - Thread to kill if the alarm fires.

Returns nothing.



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# File 'lib/cloudflock/app/common/watchdogs.rb', line 60

def set_alarm_used_space(watchdog, thread)
  watchdog.create_alarm('out_of_space') { |space| space > 0.95 }
  watchdog.on_alarm('out_of_space')     { |space| thread.kill }
end

#set_alarm_utilized_memory(watchdog, thread) ⇒ Object

Public: Set up a default alert for when swap used is > 25%, killing a given thread if it reaches that threshhold.

watchdog - Watchdog to which the alarm should be added. thread - Thread to kill if the alarm fires.

Returns nothing.



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# File 'lib/cloudflock/app/common/watchdogs.rb', line 84

def set_alarm_utilized_memory(watchdog, thread)
  watchdog.create_alarm('swapping') { |swap| swap > 0.25 }
  watchdog.on_alarm('swapping')     { |swap| thread.kill }
end

#system_load(ssh, name) ⇒ Object

Public: Create a Watchdog which monitors the system load average on a given host.

ssh - SSH session which the Watchdog should monitor. name - String describing the Watchdog.

Returns a Watchdog.



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# File 'lib/cloudflock/app/common/watchdogs.rb', line 32

def system_load(ssh, name)
  CloudFlock::Remote::SSH::Watchdog.new(name, ssh, 'uptime', 15) do |uptime|
    uptime.split(/\s+/)[-3].to_f
  end
end

#used_space(ssh, name) ⇒ Object

Public: Create a Watchdog which monitors the used disk space on a given host.

ssh - SSH session which the Watchdog should monitor. name - String describing the Watchdog.

Returns a Watchdog.



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# File 'lib/cloudflock/app/common/watchdogs.rb', line 16

def used_space(ssh, name)
  CloudFlock::Remote::SSH::Watchdog.new(name, ssh, 'df', 60) do |df|
    lines = df.lines.select { |line| /^[^ ]*(?:\s+\d+){2,}/.match line }
    total = lines.map { |line| line.split(/\s+/)[1].to_i }.reduce(&:+)
    used  = lines.map { |line| line.split(/\s+/)[2].to_i }.reduce(&:+)
    used.to_f / total
  end
end

#utilized_memory(ssh, name) ⇒ Object

Public: Create a Watchdog which monitors the memory in use on a given host.

ssh - SSH session which the Watchdog should monitor. name - String describing the Watchdog.

Returns a Watchdog.



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# File 'lib/cloudflock/app/common/watchdogs.rb', line 45

def utilized_memory(ssh, name)
  CloudFlock::Remote::SSH::Watchdog.new(name, ssh, 'free', 15) do |free|
    lines = free.lines.select { |line| /Swap/.match line }
    total,used = lines.empty? ? [0,0] : lines.map(&:to_f)[1..2]
    total > 0 ? free / total : 0.0
  end
end