Class: Resqued::Master
- Inherits:
-
Object
- Object
- Resqued::Master
- Includes:
- Logging, Pidfile, ProclineVersion, Sleepy
- Defined in:
- lib/resqued/master.rb
Overview
The master process.
-
Spawns a listener.
-
Tracks all work. (IO pipe from listener.)
-
Handles signals.
Constant Summary collapse
- SIGNALS =
[:HUP, :INT, :USR2, :CONT, :TERM, :QUIT].freeze
- OPTIONAL_SIGNALS =
[:INFO].freeze
- OTHER_SIGNALS =
[:CHLD, "EXIT"].freeze
- TRAPS =
SIGNALS + OPTIONAL_SIGNALS + OTHER_SIGNALS
- SIGNAL_QUEUE =
rubocop: disable Style/MutableConstant
[]
Instance Method Summary collapse
-
#dump_object_counts ⇒ Object
Private.
-
#go_ham ⇒ Object
Private: dat main loop.
-
#initialize(state, options = {}) ⇒ Master
constructor
A new instance of Master.
- #install_signal_handlers ⇒ Object
- #kill_all_listeners(signal) ⇒ Object
- #kill_listener(signal, listener) ⇒ Object
-
#listener_running(listener) ⇒ Object
Listener message: A listener finished booting, and is ready to start workers.
- #listener_status(listener, status) ⇒ Object
- #no_more_unexpected_exits ⇒ Object
-
#prepare_new_listener ⇒ Object
Private: Spin up a new listener.
- #read_listeners ⇒ Object
- #reap_all_listeners(waitpid_flags = 0) ⇒ Object
- #report_unexpected_exits ⇒ Object
-
#run(ready_pipe = nil) ⇒ Object
Public: Starts the master process.
- #start_listener ⇒ Object
- #status_message(type, pid, status) ⇒ Object
- #wait_for_workers ⇒ Object
-
#worker_finished(pid) ⇒ Object
Listener message: A worker just stopped working.
-
#worker_started(pid) ⇒ Object
Listener message: A worker just started working.
- #worker_status(pid, status) ⇒ Object
- #write_procline ⇒ Object
- #yawn(duration) ⇒ Object
Methods included from Sleepy
Methods included from ProclineVersion
Methods included from Pidfile
#remove_pidfile, #with_pidfile, #write_pidfile
Methods included from Logging
build_logger, close_log, #log, log_file, log_file=, #log_to_stdout?, logger, logging_io, #reopen_logs
Constructor Details
#initialize(state, options = {}) ⇒ Master
Returns a new instance of Master.
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# File 'lib/resqued/master.rb', line 21 def initialize(state, = {}) @state = state @status_pipe = .fetch(:status_pipe, nil) @listeners = ListenerPool.new(state) @listener_backoff = Backoff.new end |
Instance Method Details
#dump_object_counts ⇒ Object
Private.
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# File 'lib/resqued/master.rb', line 84 def dump_object_counts log GC.stat.inspect counts = {} total = 0 ObjectSpace.each_object do |o| count = counts[o.class.name] || 0 counts[o.class.name] = count + 1 total += 1 end top = 10 log "#{total} objects. top #{top}:" counts.sort_by { |_, count| -count }.each_with_index do |(name, count), i| next unless i < top diff = "" if last = @last_counts && @last_counts[name] diff = sprintf(" (%+d)", (count - last)) end log " #{count} #{name}#{diff}" end @last_counts = counts log GC.stat.inspect rescue => e log "Error while counting objects: #{e}" end |
#go_ham ⇒ Object
Private: dat main loop.
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# File 'lib/resqued/master.rb', line 44 def go_ham # If we're resuming, we'll want to recycle the existing listener now. prepare_new_listener loop do read_listeners reap_all_listeners(Process::WNOHANG) start_listener unless @state.paused case signal = SIGNAL_QUEUE.shift when nil yawn(@listener_backoff.how_long? || 30.0) when :INFO dump_object_counts when :HUP if @state.exec_on_hup log "Execing a new master" ExecOnHUP.exec!(@state) end reopen_logs log "Restarting listener with new configuration and application." prepare_new_listener when :USR2 log "Pause job processing" @state.paused = true kill_listener(:QUIT, @listeners.current) @listeners.clear_current! when :CONT log "Resume job processing" @state.paused = false kill_all_listeners(:CONT) when :INT, :TERM, :QUIT log "Shutting down..." kill_all_listeners(signal) wait_for_workers unless @state.fast_exit break end end end |
#install_signal_handlers ⇒ Object
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# File 'lib/resqued/master.rb', line 225 def install_signal_handlers trap(:CHLD) { awake } SIGNALS.each { |signal| trap(signal) { SIGNAL_QUEUE << signal; awake } } OPTIONAL_SIGNALS.each { |signal| trap(signal) { SIGNAL_QUEUE << signal; awake } rescue nil } end |
#kill_all_listeners(signal) ⇒ Object
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# File 'lib/resqued/master.rb', line 179 def kill_all_listeners(signal) @listeners.each do |l| l.kill(signal) end end |
#kill_listener(signal, listener) ⇒ Object
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# File 'lib/resqued/master.rb', line 175 def kill_listener(signal, listener) listener&.kill(signal) end |
#listener_running(listener) ⇒ Object
Listener message: A listener finished booting, and is ready to start workers.
Promotes a booting listener to be the current listener.
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# File 'lib/resqued/master.rb', line 144 def listener_running(listener) listener_status(listener, "ready") if listener == @listeners.current kill_listener(:QUIT, @listeners.last_good) @listeners.clear_last_good! else # This listener didn't receive the last SIGQUIT we sent. # (It was probably sent before the listener had set up its traps.) # So kill it again. We have moved on. kill_listener(:QUIT, listener) end end |
#listener_status(listener, status) ⇒ Object
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# File 'lib/resqued/master.rb', line 252 def listener_status(listener, status) if listener&.pid ("listener", listener.pid, status) end end |
#no_more_unexpected_exits ⇒ Object
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# File 'lib/resqued/master.rb', line 240 def no_more_unexpected_exits trap("EXIT", "DEFAULT") end |
#prepare_new_listener ⇒ Object
Private: Spin up a new listener.
The old one will be killed when the new one is ready for workers.
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# File 'lib/resqued/master.rb', line 160 def prepare_new_listener if @listeners.last_good # The last good listener is still running because we got another # HUP before the new listener finished booting. # Keep the last_good_listener (where all the workers are) and # kill the booting current_listener. We'll start a new one. kill_listener(:QUIT, @listeners.current) # Indicate to `start_listener` that it should start a new # listener. @listeners.clear_current! else @listeners.cycle_current end end |
#read_listeners ⇒ Object
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# File 'lib/resqued/master.rb', line 119 def read_listeners @listeners.each do |l| l.read_worker_status(on_activity: self) end end |
#reap_all_listeners(waitpid_flags = 0) ⇒ Object
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# File 'lib/resqued/master.rb', line 189 def reap_all_listeners(waitpid_flags = 0) until @listeners.empty? begin lpid, status = Process.waitpid2(-1, waitpid_flags) return unless lpid log "Listener exited #{status}" if @listeners.current_pid == lpid @listener_backoff.died @listeners.clear_current! end if @listeners.last_good_pid == lpid @listeners.clear_last_good! end if dead_listener = @listeners.delete(lpid) listener_status dead_listener, "stop" dead_listener.dispose end write_procline rescue Errno::ECHILD return end end end |
#report_unexpected_exits ⇒ Object
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# File 'lib/resqued/master.rb', line 231 def report_unexpected_exits trap("EXIT") do log("EXIT #{$!.inspect}") $!&.backtrace&.each do |line| log(line) end end end |
#run(ready_pipe = nil) ⇒ Object
Public: Starts the master process.
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# File 'lib/resqued/master.rb', line 29 def run(ready_pipe = nil) report_unexpected_exits with_pidfile(@state.pidfile) do write_procline install_signal_handlers if ready_pipe ready_pipe.syswrite($$.to_s) ready_pipe.close rescue nil end go_ham end no_more_unexpected_exits end |
#start_listener ⇒ Object
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# File 'lib/resqued/master.rb', line 110 def start_listener return if @listeners.current || @listener_backoff.wait? listener = @listeners.start! listener_status listener, "start" @listener_backoff.started write_procline end |
#status_message(type, pid, status) ⇒ Object
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# File 'lib/resqued/master.rb', line 262 def (type, pid, status) @status_pipe&.write("#{type},#{pid},#{status}\n") end |
#wait_for_workers ⇒ Object
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# File 'lib/resqued/master.rb', line 185 def wait_for_workers reap_all_listeners end |
#worker_finished(pid) ⇒ Object
Listener message: A worker just stopped working.
Forwards the message to the other listeners.
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# File 'lib/resqued/master.rb', line 133 def worker_finished(pid) worker_status(pid, "stop") @listeners.each do |other| other.worker_finished(pid) end end |
#worker_started(pid) ⇒ Object
Listener message: A worker just started working.
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# File 'lib/resqued/master.rb', line 126 def worker_started(pid) worker_status(pid, "start") end |
#worker_status(pid, status) ⇒ Object
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# File 'lib/resqued/master.rb', line 258 def worker_status(pid, status) ("worker", pid, status) end |
#write_procline ⇒ Object
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# File 'lib/resqued/master.rb', line 248 def write_procline $0 = "#{procline_version} master [gen #{@state.listeners_created}] [#{@listeners.size} running] #{ARGV.join(' ')}" end |
#yawn(duration) ⇒ Object
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# File 'lib/resqued/master.rb', line 244 def yawn(duration) super(duration, @listeners.map { |l| l.read_pipe }) end |