Class: Herdis::Shepherd::Shard

Inherits:
Object
  • Object
show all
Defined in:
lib/herdis/shepherd.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Shard

Returns a new instance of Shard.



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# File 'lib/herdis/shepherd.rb', line 20

def initialize(options = {})
  @shepherd = options.delete(:shepherd)
  @id = options.delete(:id)
  @master = options.delete(:master)
  Dir.mkdir(dir) unless Dir.exists?(dir)
  initialize_redis
end

Instance Attribute Details

#id ⇒ Object (readonly)

Returns the value of attribute id.



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# File 'lib/herdis/shepherd.rb', line 18

def id
  @id
end

#master ⇒ Object (readonly)

Returns the value of attribute master.



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# File 'lib/herdis/shepherd.rb', line 19

def master
  @master
end

#shepherd ⇒ Object (readonly)

Returns the value of attribute shepherd.



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# File 'lib/herdis/shepherd.rb', line 17

def shepherd
  @shepherd
end

Instance Method Details

#connection ⇒ Object 



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# File 'lib/herdis/shepherd.rb', line 36

def connection
  if master
    @connection ||= Redis.new(:host => "localhost", :port => port, :password => "slaved")
  else
    @connection ||= Redis.new(:host => "localhost", :port => port)
  end
end

#dir ⇒ Object 



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# File 'lib/herdis/shepherd.rb', line 27

def dir
  File.join(shepherd.dir, "shard#{id}")
end

#enslave!(external_uri) ⇒ Object 



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# File 'lib/herdis/shepherd.rb', line 68

def enslave!(external_uri)
  unless external_uri == master
    connection.shutdown
    @master = external_uri
    @connection = nil
    initialize_redis
    shepherd.masters.delete(id.to_s)
    shepherd.slaves[id.to_s] = self
    shepherd.save_config!
  end
end

#initialize_redis ⇒ Object 



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# File 'lib/herdis/shepherd.rb', line 79

def initialize_redis
  begin
    begin
      connection.shutdown          
    rescue RuntimeError => e
      if e.message == "ERR Client sent AUTH, but no password is set"
        Redis.new(:host => "localhost", :port => port).shutdown
      else
        raise e
      end
    end
  rescue Errno::ECONNREFUSED => e
  end
  io = IO.popen("#{shepherd.redis} -", "w")
  write_configuration(io)
  initialization = Proc.new do |p|
    unless master
      begin
        unless connection.get("#{self.class.name}.id")
          connection.set("#{self.class.name}.id", id) 
          connection.set("#{self.class.name}.created_at", Time.now.to_i)
          connection.set("#{self.class.name}.created_by", shepherd.shepherd_id)
        end
      rescue Errno::ECONNREFUSED => e
        EM.add_timer(0.1) do
          p.call(p)
        end
      rescue RuntimeError => e
        if e.message == "ERR operation not permitted"
          EM.add_timer(0.1) do
            p.call(p)
          end
        else
          raise e
        end
      end
    end
  end
  EM.add_timer(0.1) do
    initialization.call(initialization)
  end
end

#inmemory ⇒ Object 



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# File 'lib/herdis/shepherd.rb', line 33

def inmemory
  shepherd.inmemory
end

#inspect ⇒ Object 



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# File 'lib/herdis/shepherd.rb', line 43

def inspect
  begin
    super
  rescue Errno::ECONNREFUSED => e
    "#<#{self.class.name} @dir=#{dir} @port=#{port} CLOSED>"
  end
end

#liberate! ⇒ Object 



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# File 'lib/herdis/shepherd.rb', line 50

def liberate!
  if master
    @master = nil
    begin
      connection.slaveof("NO", "ONE")
      connection.config("set", "requirepass", "")
      shepherd.slaves.delete(id.to_s)
      shepherd.masters[id.to_s] = self
      shepherd.save_config!
    rescue RuntimeError => e
      if e.message == "LOADING Redis is loading the dataset in memory"
        EM::Synchrony.sleep(0.1)
      else
        raise e
      end
    end
  end
end

#port ⇒ Object 



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# File 'lib/herdis/shepherd.rb', line 30

def port
  shepherd.first_port + id.to_i
end

#write_configuration(io) ⇒ Object 



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# File 'lib/herdis/shepherd.rb', line 121

def write_configuration(io)
  io.puts("daemonize yes")
  io.puts("pidfile #{dir}/pid")
  io.puts("port #{port}")
  io.puts("timeout 300")
  if master
    io.puts("slaveof #{master.host} #{master.port}")
    io.puts("requirepass slaved")
  end
  unless inmemory
    io.puts("save 900 1")
    io.puts("save 300 10")
    io.puts("save 60 10000")
    io.puts("dbfilename dump.rdb")
  end
  io.puts("dir #{dir}")
  io.puts("logfile stdout")
  io.close
end