Class: RQ::Feeder

Inherits:
MainHelper show all
Defined in:
lib/rq-0.1.7/feeder.rb

Constant Summary collapse

DEFAULT_MIN_SLEEP =

{{{

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DEFAULT_MAX_SLEEP = 
240
DEFAULT_FEED = 
2

Constants included from Logging

Logging::DIV0, Logging::DIV1, Logging::DIV2, Logging::DIV3, Logging::EOL, Logging::SEC0, Logging::SEC1, Logging::SEC2, Logging::SEC3

Class Attribute Summary collapse

Attributes inherited from MainHelper

#argv, #cmd, #env, #logger, #main, #mode, #options, #q, #qpath

Instance Method Summary collapse

Methods inherited from MainHelper

#initialize, #set_q

Methods included from Logging

append_features

Methods included from Logging::LogMethods

#debug, #error, #fatal, #info, #logerr, #logger, #logger=, #warn

Methods included from Util

#alive?, append_features, #btrace, #columnize, #defval, #emsg, #erreq, #errmsg, #escape, #escape!, #exec, export, #fork, #getopt, #hashify, #host, #hostname, #klass, #maim, #mcp, #realpath, #stamptime, #system, #timestamp, #tmpnam, #uncache

Constructor Details

This class inherits a constructor from RQ::MainHelper

Class Attribute Details

.feed ⇒ Object

Returns the value of attribute feed.



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# File 'lib/rq-0.1.7/feeder.rb', line 23

def feed
  @feed
end

.max_sleep ⇒ Object

Returns the value of attribute max_sleep.



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# File 'lib/rq-0.1.7/feeder.rb', line 22

def max_sleep
  @max_sleep
end

.min_sleep ⇒ Object

{{{



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# File 'lib/rq-0.1.7/feeder.rb', line 21

def min_sleep
  @min_sleep
end

Instance Method Details

#busy? ⇒ Boolean

}}}

Returns:

  • (Boolean) 


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# File 'lib/rq-0.1.7/feeder.rb', line 350

def busy?
    #{{{
  @children.size >= @max_feed
    #}}}
end

#daemon ⇒ Object

}}}



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# File 'lib/rq-0.1.7/feeder.rb', line 73

def daemon
    #{{{
  if @options['daemon']
    fork do
      Process::setsid
      fork do
        Dir::chdir(Util.realpath('~'))
        File::umask 0
        open('/dev/null','r+') do |f|
          STDIN.reopen f 
          STDOUT.reopen f 
          STDERR.reopen f 
        end
        @daemon = true
        yield
        exit EXIT_SUCCESS
      end
      exit!
    end
    exit!
  else
    @daemon = false 
    yield
    exit EXIT_SUCCESS
  end
    #}}}
end

#feed ⇒ Object 



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# File 'lib/rq-0.1.7/feeder.rb', line 27

def feed
    #{{{
  daemon do
    gen_pidfile
    @main.init_logging
    @logger = @main.logger
    set_q

    @pid = Process::pid
    @cmd = @main.cmd 
    @started = Util::timestamp
    @min_sleep = Integer(@options['min_sleep'] || defval('min_sleep'))
    @max_sleep = Integer(@options['max_sleep'] || defval('max_sleep'))
    @max_feed = Integer(@options['feed'] || defval('feed'))
    @children = Hash::new 
    @jrd = JobRunnerDaemon::daemon

    install_signal_handlers

    info{ "** STARTED **" }
    info{ "version <#{ RQ::VERSION }>" }
    info{ "cmd <#{ @cmd }>" }
    info{ "pid <#{ @pid }>" }
    info{ "pidfile <#{ @pidfile.path }>" }
    info{ "jobrunnerdaemon uri <#{ @jrd.uri }> pid <#{ @jrd.pid }>" }
    info{ "qpath <#{ @qpath }>" }
    info{ "mode <#{ @mode }>" }
    debug{ "min_sleep <#{ @min_sleep }>" }
    debug{ "max_sleep <#{ @max_sleep }>" }

    fill_morgue

    loop do
      handle_signal if $rq_signaled
      throttle(@min_sleep) do
        start_jobs unless busy?
        if nothing_running?
          relax
        else
          reap_jobs
        end
      end
    end
  end
    #}}}
end

#fill_morgue ⇒ Object

}}}



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# File 'lib/rq-0.1.7/feeder.rb', line 158

def fill_morgue
    #{{{
  debug{ "filling morgue" }
  sql = <<-sql
    select * from jobs where state = 'running' and runner = '#{ Util::hostname }' and started <= '#{ @started }'
  sql
  db = @q.qdb
  transaction do
    tuples = db.execute sql
    tuples.each do |tuple|
      jid = tuple['jid']
      if jid
        sql = "update jobs set state='dead' where jid='#{ jid }'"
        db.execute sql
        info{ "burried job <#{ jid }>" }
      end
    end
  end
  debug{ "filled morgue" }
    #}}}
end

#finish_job(job, status) ⇒ Object

}}}



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# File 'lib/rq-0.1.7/feeder.rb', line 320

def finish_job job, status
    #{{{
  job['finished'] = Util::timestamp(Time::now)
  job['elapsed'] = Util::stamptime(job['finished']) - Util::stamptime(job['started'])
  t = status.exitstatus rescue nil 
  job['exit_status'] = t 
  job['state'] = 'finished' 
  if t and t == 0
    info{ "finished - jid <#{ job['jid'] }> pid <#{ job['pid'] }> exit_status <#{ job['exit_status'] }>" }
  else
    warn{ "finished - jid <#{ job['jid'] }> pid <#{ job['pid'] }> exit_status <#{ job['exit_status'] }>" }
  end
    #}}}
end

#gen_feeder_name(path) ⇒ Object

}}}



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# File 'lib/rq-0.1.7/feeder.rb', line 126

def gen_feeder_name path 
    #{{{
  path = Util::realpath(path).gsub(%r|/|o, '_')
  File::join(Util::realpath('~'), ".#{ path }.feeder")
    #}}}
end

#gen_pidfile(name = nil) ⇒ Object

}}}



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# File 'lib/rq-0.1.7/feeder.rb', line 100

def gen_pidfile name = nil
    #{{{
  name ||= gen_feeder_name(@options['name'] || @qpath)
  @pidfile = 
    begin
      open name, File::CREAT | File::EXCL | File::RDWR
    rescue
      open name, File::RDWR
    end
  unless @pidfile and @pidfile.posixlock(File::LOCK_EX | File::LOCK_NB)
    pid = IO::read(name) rescue nil
    pid ||= 'unknown'
    if @options['quiet']
      exit EXIT_FAILURE
    else
      raise "process <#{ pid }> is already feeding from this queue"
    end
  else
    @pidfile.rewind
    @pidfile.sync = true
    @pidfile.print Process::pid
    @pidfile.truncate @pidfile.pos
    at_exit{ FileUtils::rm_f name rescue nil }
  end
    #}}}
end

#handle_signal ⇒ Object

}}}



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# File 'lib/rq-0.1.7/feeder.rb', line 179

def handle_signal
#{{{
  if $rq_sigterm or $rq_sigint
    reap_jobs(reap_only = true) until nothing_running? 
    info{ "** STOPPING **" }
    @jrd.shutdown rescue nil
    @pidfile.posixlock File::LOCK_UN
    exit EXIT_SUCCESS
  end

  if $rq_sighup
    reap_jobs(reap_only = true) until nothing_running? 
    info{ "** RESTARTING **" }
    @jrd.shutdown rescue nil
    Util::uncache __FILE__ 
    @pidfile.posixlock File::LOCK_UN
    Util::exec @cmd
  end
#}}}
end

#install_signal_handlers ⇒ Object

}}}



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# File 'lib/rq-0.1.7/feeder.rb', line 132

def install_signal_handlers
#{{{
  if @daemon
    $rq_signaled = false
    $rq_sighup = false
    $rq_sigterm = false
    $rq_sigint = false
    trap('SIGHUP') do
      $rq_signaled = $rq_sighup = 'SIGHUP' 
      warn{ "signal <SIGHUP>" }
      warn{ "finishing running jobs before handling signal" }
    end
    trap('SIGTERM') do
      $rq_signaled = $rq_sigterm = 'SIGTERM' 
      warn{ "signal <SIGTERM>" }
      warn{ "finishing running jobs before handling signal" }
    end
    trap('SIGINT') do
      $rq_signaled = $rq_sigint = 'SIGINT' 
      warn{ "signal <SIGINT>" }
      warn{ "finishing running jobs before handling signal" }
    end
    @jrd.install_signal_handlers
  end
#}}}
end

#nothing_running? ⇒ Boolean

}}}

Returns:

  • (Boolean) 


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# File 'lib/rq-0.1.7/feeder.rb', line 257

def nothing_running?
    #{{{
  @children.size == 0
    #}}}
end

#reap_jobs(reap_only = false, blocking = true) ⇒ Object

}}}



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# File 'lib/rq-0.1.7/feeder.rb', line 262

def reap_jobs reap_only = false, blocking = true
    #{{{
  reaped = []

  cid = status = nil
    
  if blocking
    if busy? or reap_only
      cid, status = @jrd.waitpid2 -1, Process::WUNTRACED 
    else
      loop do
        debug{ "not busy wait loop" }
        cid, status = @jrd.waitpid2 -1, Process::WNOHANG | Process::WUNTRACED 
        break if cid
        start_jobs unless $rq_signaled
        break if busy?
        cid, status = @jrd.waitpid2 -1, Process::WNOHANG | Process::WUNTRACED 
        break if cid
        sleep 4.2 
      end
      cid, status = @jrd.waitpid2 -1, Process::WUNTRACED unless cid
    end
  else
    cid, status = @jrd.waitpid2 -1, Process::WNOHANG | Process::WUNTRACED 
  end
    
  if cid and status
    job = @children[cid]
    finish_job job, status
    
    transaction do
      loopno = 0
      loop do
        @q.jobisdone job
        @children.delete cid
        reaped << cid
    
        start_jobs unless reap_only or $rq_signaled
    
        if @children.size == 0 or loopno > 42
          break
        else
          sleep 0.1
          cid, status = @jrd.waitpid2 -1, Process::WNOHANG | Process::WUNTRACED 
          break unless cid and status
          job = @children[cid]
          finish_job job, status
        end
        loopno += 1
      end
    end
  end
    
  debug{ "<#{ reaped.size }> jobs reaped" }
    
  reaped
    #}}}
end

#relax ⇒ Object

}}}



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# File 'lib/rq-0.1.7/feeder.rb', line 355

def relax
    #{{{
  seconds = rand(@max_sleep - @min_sleep + 1) + @min_sleep
  debug{ "relaxing <#{ seconds }>" }
  sleep seconds
    #}}}
end

#start_job(job) ⇒ Object

}}}



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# File 'lib/rq-0.1.7/feeder.rb', line 230

def start_job job
    #{{{
  jid, command = job['jid'], job['command']

#
# we setup state slightly prematurely so jobrunner will have it availible
#
  job['state'] = 'running'
  job['started'] = Util::timestamp Time::now
  job['runner'] = Util::hostname 

  jr = @jrd.runner job
  cid = jr.cid
    
  if jr and cid
    jr.run
    job['pid'] = cid
    @children[cid] = job
    @q.jobisrunning job
    info{ "started - jid <#{ job['jid'] }> pid <#{ job['pid'] }> command <#{ job['command'] }>" }
  else
    error{ "not started - jid <#{ job['jid'] }> command <#{ job['command'] }>" }
  end
    
  cid
    #}}}
end

#start_jobs ⇒ Object

}}}



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# File 'lib/rq-0.1.7/feeder.rb', line 216

def start_jobs
    #{{{
  n_started = 0 
  transaction do
    until busy?
      break unless((job = @q.getjob))
      start_job job
      n_started += 1 
    end
  end
  debug{ "<#{ n_started }> jobs started" }
  n_started
    #}}}
end

#throttle(rate = @min_sleep) ⇒ Object

}}}



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# File 'lib/rq-0.1.7/feeder.rb', line 199

def throttle rate = @min_sleep 
    #{{{
  if Numeric === rate and rate > 0 
    if defined? @last_throttle_time and @last_throttle_time
      elapsed = Time.now - @last_throttle_time
      timeout = rate - elapsed
      if timeout > 0
        timeout = timeout + rand(rate * 0.10)
        debug{ "throttle rate of <#{ rate }> exceeded - sleeping <#{ timeout }>" }
        sleep timeout
      end
    end
    @last_throttle_time = Time.now 
  end
  yield
    #}}}
end

#transaction ⇒ Object

}}}



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# File 'lib/rq-0.1.7/feeder.rb', line 334

def transaction
    #{{{
  ret = nil
  if @in_transaction
    ret = yield
  else
    begin
      @in_transaction = true
      @q.transaction{ ret = yield }
    ensure
      @in_transaction = false 
    end
  end
  ret
    #}}}
end