Class: God::Conditions::MemoryUsage

Inherits:
PollCondition show all
Defined in:
lib/god/conditions/memory_usage.rb

Overview

Condition Symbol :memory_usage Type: Poll

Trigger when the resident memory of a process is above a specified limit.

Parameters

Required
  +pid_file+ is the pid file of the process in question. Automatically
             populated for Watches.
  +above+ is the amount of resident memory (in kilobytes) above which
          the condition should trigger. You can also use the sugar
          methods #kilobytes, #megabytes, and #gigabytes to clarify
          this amount (see examples).

Examples

Trigger if the process is using more than 100 megabytes of resident memory (from a Watch):

on.condition(:memory_usage) do |c|
  c.above = 100.megabytes
end

Non-Watch Tasks must specify a PID file:

on.condition(:memory_usage) do |c|
  c.above = 100.megabytes
  c.pid_file = "/var/run/mongrel.3000.pid"
end

Instance Attribute Summary collapse

Attributes inherited from PollCondition

#interval

Attributes inherited from God::Condition

#info, #notify, #phase, #transition

Attributes inherited from Behavior

#watch

Instance Method Summary collapse

Methods inherited from PollCondition

#after, #before

Methods inherited from God::Condition

#friendly_name, generate, valid?

Methods inherited from Behavior

#after_restart, #after_start, #after_stop, #before_restart, #before_start, #before_stop, #friendly_name, generate

Methods included from God::Configurable

#base_name, complain, #complain, #friendly_name

Constructor Details

#initialize ⇒ MemoryUsage

Returns a new instance of MemoryUsage.



37
38
39
40
41
 
# File 'lib/god/conditions/memory_usage.rb', line 37

def initialize
  super
  self.above = nil
  self.times = [1, 1]
end

Instance Attribute Details

#above ⇒ Object

Returns the value of attribute above.



35
36
37
 
# File 'lib/god/conditions/memory_usage.rb', line 35

def above
  @above
end

#pid_file ⇒ Object

Returns the value of attribute pid_file.



35
36
37
 
# File 'lib/god/conditions/memory_usage.rb', line 35

def pid_file
  @pid_file
end

#times ⇒ Object

Returns the value of attribute times.



35
36
37
 
# File 'lib/god/conditions/memory_usage.rb', line 35

def times
  @times
end

Instance Method Details

#pid ⇒ Object 



53
54
55
 
# File 'lib/god/conditions/memory_usage.rb', line 53

def pid
  pid_file ? File.read(pid_file).strip.to_i : watch.pid
end

#prepare ⇒ Object 



43
44
45
46
47
 
# File 'lib/god/conditions/memory_usage.rb', line 43

def prepare
  self.times = [times, times] if times.is_a?(Integer)

  @timeline = Timeline.new(times[1])
end

#reset ⇒ Object 



49
50
51
 
# File 'lib/god/conditions/memory_usage.rb', line 49

def reset
  @timeline.clear
end

#test ⇒ Object 



64
65
66
67
68
69
70
71
72
73
74
75
76
77
 
# File 'lib/god/conditions/memory_usage.rb', line 64

def test
  process = System::Process.new(pid)
  @timeline.push(process.memory)
  self.info = []

  history = @timeline.map { |x| "#{x > above ? '*' : ''}#{x}kb" }.join(', ')

  if @timeline.count { |x| x > above } >= times.first
    self.info = "memory out of bounds [#{history}]"
    true
  else
    false
  end
end

#valid? ⇒ Boolean

Returns:

  • (Boolean) 


57
58
59
60
61
62
 
# File 'lib/god/conditions/memory_usage.rb', line 57

def valid?
  valid = true
  valid &= complain("Attribute 'pid_file' must be specified", self) if pid_file.nil? && watch.pid_file.nil?
  valid &= complain("Attribute 'above' must be specified", self) if above.nil?
  valid
end