Class: ModernTimes::Manager

Inherits:
Object
  • Object
show all
Defined in:
lib/modern_times/manager.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config = {}) ⇒ Manager

Constructs a manager. Accepts a hash of config values

allowed_workers - array of allowed worker classes.  For a rails project, this will be set to the
  classes located in the app/workers directory which are a kind_of? ModernTimes::Base::Worker
dummy_host - name to use for host as defined by the worker_file.  For a rails project, this will be the value of Rails.env
  such that a set of workers can be defined for development without having to specify the hostname.  For production, a set of
  workers could be defined under production or specific workers for each host name



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# File 'lib/modern_times/manager.rb', line 16

def initialize(config={})
  @stopped = false
  @config = config
  @domain = config[:domain] || ModernTimes::DEFAULT_DOMAIN
  # Unless specifically unconfigured (i.e., Rails.env == test), then enable jmx
  if config[:jmx] != false
    @jmx_server = JMX::MBeanServer.new
    bean = ManagerMBean.new(@domain, self)
    @jmx_server.register_mbean(bean, ModernTimes.manager_mbean_object_name(@domain))
  end
  @supervisors = []
  @dummy_host = config[:dummy_host]
  self.persist_file = config[:persist_file]
  self.worker_file  = config[:worker_file]
  @allowed_workers = config[:allowed_workers]
  stop_on_signal if config[:stop_on_signal]
end

Instance Attribute Details

#allowed_workers ⇒ Object

Returns the value of attribute allowed_workers.



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# File 'lib/modern_times/manager.rb', line 7

def allowed_workers
  @allowed_workers
end

#dummy_host ⇒ Object

Returns the value of attribute dummy_host.



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# File 'lib/modern_times/manager.rb', line 7

def dummy_host
  @dummy_host
end

#supervisors ⇒ Object (readonly)

Returns the value of attribute supervisors.



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# File 'lib/modern_times/manager.rb', line 8

def supervisors
  @supervisors
end

Class Method Details

.parse_worker_file(file, dummy_host, &block) ⇒ Object

Parse the worker file sending the yield block the class, count and options for each worker. This is a big kludge to let dummy publishing share this parsing code for Railsable in order to setup dummy workers. Think about a refactor where the manager knows about dummy publishing mode? Get the previous version to unkludge.



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# File 'lib/modern_times/manager.rb', line 150

def self.parse_worker_file(file, dummy_host, &block)
  if File.exist?(file)
    hash = YAML.load(ERB.new(File.read(file)).result(binding))
    config = dummy_host && hash[dummy_host]
    unless config
      host = Socket.gethostname.sub(/\..*/, '')
      config = hash[host]
    end
    return unless config
    config.each do |worker_name, worker_hash|
      klass_name     = worker_hash[:class] || worker_hash[:klass] || "#{worker_name}Worker"  # Backwards compat, remove :klass in next release
      klass          = Object.const_get(klass_name.to_s)
      count          = worker_hash[:count]
      options        = worker_hash[:options] || {}
      options[:name] = worker_name
      yield(klass, count, options)
    end
  end
end

Instance Method Details

#add(worker_klass, num_workers, worker_options = {}) ⇒ Object 



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# File 'lib/modern_times/manager.rb', line 34

def add(worker_klass, num_workers, worker_options={})
  ModernTimes.logger.info "Starting #{worker_klass} with #{num_workers} workers with options #{worker_options.inspect}"
  unless worker_klass.kind_of?(Class)
    begin
      worker_klass = Object.const_get(worker_klass.to_s)
    rescue
      raise "Invalid class: #{worker_klass}"
    end
  end
  if @allowed_workers && !@allowed_workers.include?(worker_klass)
    raise "Error: #{worker_klass.name} is not an allowed worker"
  end
  supervisor = worker_klass.create_supervisor(self, worker_options)
  raise "A supervisor with name #{supervisor.name} already exists" if find_supervisor(supervisor.name)
  @supervisors << supervisor
  supervisor.worker_count = num_workers
  if @jmx_server
    mbean = supervisor.create_mbean(@domain)
    @jmx_server.register_mbean(mbean, "#{@domain}:worker=#{supervisor.name},type=Worker")
  end
  ModernTimes.logger.info "Started #{worker_klass.name} named #{supervisor.name} with #{num_workers} workers"
rescue Exception => e
  ModernTimes.logger.error "Exception trying to add #{worker_klass}: #{e.message}\n\t#{e.backtrace.join("\n\t")}"
  raise
rescue java.lang.Exception => e
  ModernTimes.logger.error "Java exception trying to add #{worker_klass.name}: #{e.message}\n\t#{e.backtrace.join("\n\t")}"
  raise
end

#find_supervisor(name) ⇒ Object 



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# File 'lib/modern_times/manager.rb', line 123

def find_supervisor(name)
  @supervisors.each do |supervisor|
    return supervisor if supervisor.name == name
  end
  return nil
end

#join ⇒ Object 



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# File 'lib/modern_times/manager.rb', line 75

def join
  while !@stopped
    sleep 1
  end
  @supervisors.each { |supervisor| supervisor.join }
end

#persist_file=(file) ⇒ Object 



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# File 'lib/modern_times/manager.rb', line 91

def persist_file=(file)
  return if @persist_file == file
  @persist_file = nil
  return unless file
  if File.exist?(file)
    hash = YAML.load_file(file)
    hash.each do |worker_name, worker_hash|
      klass   = worker_hash[:class] || worker_hash[:klass] # Backwards compat, remove klass in next release
      count   = worker_hash[:count]
      options = worker_hash[:options]
      options[:name] = worker_name
      add(klass, count, options)
    end
  end
  @persist_file = file
end

#save_persist_state ⇒ Object 



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# File 'lib/modern_times/manager.rb', line 108

def save_persist_state
  return unless @persist_file
  hash = {}
  @supervisors.each do |supervisor|
    hash[supervisor.name] = {
      :class   => supervisor.worker_klass.name,
      :count   => supervisor.worker_count,
      :options => supervisor.worker_options
    }
  end
  File.open(@persist_file, 'w') do |out|
    YAML.dump(hash, out )
  end
end

#start ⇒ Object

TODO: Get rid of this or prevent worker thread creation until it’s been called?



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# File 'lib/modern_times/manager.rb', line 64

def start
  return if @started
  @started = true
end

#stop ⇒ Object 



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# File 'lib/modern_times/manager.rb', line 69

def stop
  return if @stopped
  @stopped = true
  @supervisors.each { |supervisor| supervisor.stop }
end

#stop_on_signal ⇒ Object 



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# File 'lib/modern_times/manager.rb', line 82

def stop_on_signal
  ['HUP', 'INT', 'TERM'].each do |signal_name|
    Signal.trap(signal_name) do
      ModernTimes.logger.info "Caught #{signal_name}"
      stop
    end
  end
end

#worker_file=(file) ⇒ Object 



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# File 'lib/modern_times/manager.rb', line 130

def worker_file=(file)
  return unless file
  @worker_file = file
  # Don't save new states if the user never dynamically updates the workers
  # Then they can solely define the workers via this file and updates to the counts won't be ignored.
  save_persist_file = @persist_file
  @persist_file = nil unless File.exist?(@persist_file)
  begin
    self.class.parse_worker_file(file, @dummy_host) do |klass, count, options|
      # Don't add if persist_file already created this supervisor
      add(klass, count, options) unless find_supervisor(options[:name])
    end
  ensure
    @persist_file = save_persist_file
  end
end