Module: Einhorn::Command
- Defined in:
- lib/einhorn/command.rb,
lib/einhorn/command/interface.rb
Defined Under Namespace
Modules: Interface
Class Method Summary collapse
- .cull ⇒ Object
- .decrement ⇒ Object
- .dumpable_state ⇒ Object
- .full_upgrade ⇒ Object
- .increment ⇒ Object
- .louder(log = true) ⇒ Object
-
.mourn(pid) ⇒ Object
Mourn the death of your child.
- .prepare_child_environment ⇒ Object
- .prepare_child_process ⇒ Object
- .quieter(log = true) ⇒ Object
- .reap ⇒ Object
- .register_ack(pid) ⇒ Object
- .register_manual_ack(pid) ⇒ Object
- .register_timer_ack(time, pid) ⇒ Object
- .reload ⇒ Object
- .reload_for_preload_upgrade ⇒ Object
- .replenish ⇒ Object
- .replenish_gradually ⇒ Object
- .replenish_immediately ⇒ Object
- .signal_all(signal, children = nil, record = true) ⇒ Object
- .spinup(cmd = nil) ⇒ Object
- .upgrade_workers ⇒ Object
Class Method Details
.cull ⇒ Object
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# File 'lib/einhorn/command.rb', line 315 def self.cull acked = Einhorn::WorkerPool.ack_count target = Einhorn::WorkerPool.ack_target if Einhorn::State.upgrading && acked >= target Einhorn::State.upgrading = false Einhorn.log_info("Upgrade to version #{Einhorn::State.version} complete.") end old_workers = Einhorn::WorkerPool.old_workers if !Einhorn::State.upgrading && old_workers.length > 0 Einhorn.log_info("Killing off #{old_workers.length} old workers.") signal_all("USR2", old_workers) end if acked > target excess = Einhorn::WorkerPool.acked_unsignaled_modern_workers[0...(acked-target)] Einhorn.log_info("Have too many workers at the current version, so killing off #{excess.length} of them.") signal_all("USR2", excess) end end |
.decrement ⇒ Object
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# File 'lib/einhorn/command.rb', line 140 def self.decrement if Einhorn::State.config[:number] <= 1 output = "Can't decrease number of workers (already at #{Einhorn::State.config[:number]}). Run kill #{$$} if you really want to kill einhorn." $stderr.puts(output) return output end Einhorn::Event.break_loop old = Einhorn::State.config[:number] new = (Einhorn::State.config[:number] -= 1) output = "Decrementing number of workers from #{old} -> #{new}" $stderr.puts(output) output end |
.dumpable_state ⇒ Object
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# File 'lib/einhorn/command.rb', line 155 def self.dumpable_state global_state = Einhorn::State.state descriptor_state = Einhorn::Event.persistent_descriptors.map do |descriptor| descriptor.to_state end { :state => global_state, :persistent_descriptors => descriptor_state } end |
.full_upgrade ⇒ Object
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# File 'lib/einhorn/command.rb', line 284 def self.full_upgrade if Einhorn::State.path && !Einhorn::State.reloading_for_preload_upgrade reload_for_preload_upgrade else upgrade_workers end end |
.increment ⇒ Object
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# File 'lib/einhorn/command.rb', line 131 def self.increment Einhorn::Event.break_loop old = Einhorn::State.config[:number] new = (Einhorn::State.config[:number] += 1) output = "Incrementing number of workers from #{old} -> #{new}" $stderr.puts(output) output end |
.louder(log = true) ⇒ Object
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# File 'lib/einhorn/command.rb', line 394 def self.louder(log=true) Einhorn::State.verbosity -= 1 if Einhorn::State.verbosity > 0 output = "Verbosity set to #{Einhorn::State.verbosity}" Einhorn.log_info(output) if log output end |
.mourn(pid) ⇒ Object
Mourn the death of your child
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# File 'lib/einhorn/command.rb', line 24 def self.mourn(pid) unless spec = Einhorn::State.children[pid] Einhorn.log_error("Could not find any config for exited child #{pid.inspect}! This probably indicates a bug in Einhorn.") return end Einhorn::State.children.delete(pid) # Unacked worker if spec[:type] == :worker && !spec[:acked] Einhorn::State.consecutive_deaths_before_ack += 1 extra = ' before it was ACKed' else extra = nil end case type = spec[:type] when :worker Einhorn.log_info("===> Exited worker #{pid.inspect}#{extra}") when :state_passer Einhorn.log_debug("===> Exited state passing process #{pid.inspect}") else Einhorn.log_error("===> Exited process #{pid.inspect} has unrecgonized type #{type.inspect}: #{spec.inspect}") end end |
.prepare_child_environment ⇒ Object
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# File 'lib/einhorn/command.rb', line 260 def self.prepare_child_environment # This is run from the child ENV['EINHORN_MASTER_PID'] = Process.ppid.to_s ENV['EINHORN_SOCK_PATH'] = Einhorn::Command::Interface.socket_path if Einhorn::State.command_socket_as_fd socket = UNIXSocket.open(Einhorn::Command::Interface.socket_path) Einhorn::TransientState.socket_handles << socket ENV['EINHORN_SOCK_FD'] = socket.fileno.to_s end ENV['EINHORN_FD_COUNT'] = Einhorn::State.bind_fds.length.to_s Einhorn::State.bind_fds.each_with_index {|fd, i| ENV["EINHORN_FD_#{i}"] = fd.to_s} # EINHORN_FDS is deprecated. It was originally an attempt to # match Upstart's nominal internal support for space-separated # FD lists, but nobody uses that in practice, and it makes # finding individual FDs more difficult ENV['EINHORN_FDS'] = Einhorn::State.bind_fds.map(&:to_s).join(' ') end |
.prepare_child_process ⇒ Object
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# File 'lib/einhorn/command.rb', line 280 def self.prepare_child_process Einhorn.renice_self end |
.quieter(log = true) ⇒ Object
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# File 'lib/einhorn/command.rb', line 387 def self.quieter(log=true) Einhorn::State.verbosity += 1 if Einhorn::State.verbosity < 2 output = "Verbosity set to #{Einhorn::State.verbosity}" Einhorn.log_info(output) if log output end |
.reap ⇒ Object
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# File 'lib/einhorn/command.rb', line 9 def self.reap begin while true Einhorn.log_debug('Going to reap a child process') pid = Process.wait(-1, Process::WNOHANG) return unless pid mourn(pid) Einhorn::Event.break_loop end rescue Errno::ECHILD end end |
.register_ack(pid) ⇒ Object
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# File 'lib/einhorn/command.rb', line 77 def self.register_ack(pid) unless spec = Einhorn::State.children[pid] Einhorn.log_error("Could not find state for PID #{pid.inspect}; ignoring ACK.") return end if spec[:acked] Einhorn.log_error("Pid #{pid.inspect} already ACKed; ignoring new ACK.") return end if Einhorn::State.consecutive_deaths_before_ack > 0 extra = ", breaking the streak of #{Einhorn::State.consecutive_deaths_before_ack} consecutive unacked workers dying" else extra = nil end Einhorn::State.consecutive_deaths_before_ack = 0 spec[:acked] = true Einhorn.log_info("Up to #{Einhorn::WorkerPool.ack_count} / #{Einhorn::WorkerPool.ack_target} #{Einhorn::State.ack_mode[:type]} ACKs#{extra}") # Could call cull here directly instead, I believe. Einhorn::Event.break_loop end |
.register_manual_ack(pid) ⇒ Object
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# File 'lib/einhorn/command.rb', line 50 def self.register_manual_ack(pid) ack_mode = Einhorn::State.ack_mode unless ack_mode[:type] == :manual Einhorn.log_error("Received a manual ACK for #{pid.inspect}, but ack_mode is #{ack_mode.inspect}. Ignoring ACK.") return end Einhorn.log_info("Received a manual ACK from #{pid.inspect}") register_ack(pid) end |
.register_timer_ack(time, pid) ⇒ Object
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# File 'lib/einhorn/command.rb', line 60 def self.register_timer_ack(time, pid) ack_mode = Einhorn::State.ack_mode unless ack_mode[:type] == :timer Einhorn.log_error("Received a timer ACK for #{pid.inspect}, but ack_mode is #{ack_mode.inspect}. Ignoring ACK.") return end unless Einhorn::State.children[pid] # TODO: Maybe cancel pending ACK timers upon death? Einhorn.log_debug("Worker #{pid.inspect} died before its timer ACK happened.") return end Einhorn.log_info("Worker #{pid.inspect} has been up for #{time}s, so we are considering it alive.") register_ack(pid) end |
.reload ⇒ Object
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# File 'lib/einhorn/command.rb', line 167 def self.reload unless Einhorn::State.respawn Einhorn.log_info("Not reloading einhorn because we're exiting") return end Einhorn.log_info("Reloading einhorn (#{Einhorn::TransientState.script_name})...") # In case there's anything lurking $stdout.flush # Spawn a child to pass the state through the pipe read, write = IO.pipe fork do Einhorn::TransientState.whatami = :state_passer Einhorn::State.generation += 1 Einhorn::State.children[$$] = { :type => :state_passer } read.close write.write(YAML.dump(dumpable_state)) write.close exit(0) end write.close # Reload the original environment ENV.clear ENV.update(Einhorn::TransientState.environ) begin exec [Einhorn::TransientState.script_name, Einhorn::TransientState.script_name], *(['--with-state-fd', read.fileno.to_s, '--'] + Einhorn::State.cmd) rescue SystemCallError => e Einhorn.log_error("Could not reload! Attempting to continue. Error was: #{e}") Einhorn::State.reloading_for_preload_upgrade = false read.close end end |
.reload_for_preload_upgrade ⇒ Object
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# File 'lib/einhorn/command.rb', line 292 def self.reload_for_preload_upgrade Einhorn::State.reloading_for_preload_upgrade = true reload end |
.replenish ⇒ Object
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# File 'lib/einhorn/command.rb', line 337 def self.replenish return unless Einhorn::State.respawn if !Einhorn::State.last_spinup replenish_immediately else replenish_gradually end end |
.replenish_gradually ⇒ Object
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# File 'lib/einhorn/command.rb', line 357 def self.replenish_gradually return if Einhorn::TransientState.has_outstanding_spinup_timer return unless Einhorn::WorkerPool.missing_worker_count > 0 # Exponentially backoff automated spinup if we're just having # things die before ACKing spinup_interval = Einhorn::State.config[:seconds] * (1.5 ** Einhorn::State.consecutive_deaths_before_ack) seconds_ago = (Time.now - Einhorn::State.last_spinup).to_f if seconds_ago > spinup_interval msg = "Last spinup was #{seconds_ago}s ago, and spinup_interval is #{spinup_interval}s, so spinning up a new process" if Einhorn::State.consecutive_deaths_before_ack > 0 Einhorn.log_info("#{msg} (there have been #{Einhorn::State.consecutive_deaths_before_ack} consecutive unacked worker deaths)") else Einhorn.log_debug(msg) end spinup else Einhorn.log_debug("Last spinup was #{seconds_ago}s ago, and spinup_interval is #{spinup_interval}s, so not spinning up a new process") end Einhorn::TransientState.has_outstanding_spinup_timer = true Einhorn::Event::Timer.open(spinup_interval) do Einhorn::TransientState.has_outstanding_spinup_timer = false replenish end end |
.replenish_immediately ⇒ Object
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# File 'lib/einhorn/command.rb', line 347 def self.replenish_immediately missing = Einhorn::WorkerPool.missing_worker_count if missing <= 0 Einhorn.log_error("Missing is currently #{missing.inspect}, but should always be > 0 when replenish_immediately is called. This probably indicates a bug in Einhorn.") return end Einhorn.log_info("Launching #{missing} new workers") missing.times {spinup} end |
.signal_all(signal, children = nil, record = true) ⇒ Object
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# File 'lib/einhorn/command.rb', line 101 def self.signal_all(signal, children=nil, record=true) children ||= Einhorn::WorkerPool.workers signaled = [] Einhorn.log_info("Sending #{signal} to #{children.inspect}") children.each do |child| unless spec = Einhorn::State.children[child] Einhorn.log_error("Trying to send #{signal} to dead child #{child.inspect}. The fact we tried this probably indicates a bug in Einhorn.") next end if record if spec[:signaled].include?(signal) Einhorn.log_error("Re-sending #{signal} to already-signaled child #{child.inspect}. It may be slow to spin down, or it may be swallowing #{signal}s.") end spec[:signaled].add(signal) end begin Process.kill(signal, child) rescue Errno::ESRCH else signaled << child end end "Successfully sent #{signal}s to #{signaled.length} processes: #{signaled.inspect}" end |
.spinup(cmd = nil) ⇒ Object
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# File 'lib/einhorn/command.rb', line 208 def self.spinup(cmd=nil) cmd ||= Einhorn::State.cmd if Einhorn::TransientState.preloaded pid = fork do Einhorn::TransientState.whatami = :worker prepare_child_process Einhorn.log_info('About to tear down Einhorn state and run einhorn_main') Einhorn::Command::Interface.uninit Einhorn::Event.close_all_for_worker Einhorn.set_argv(cmd, true) prepare_child_environment einhorn_main end else pid = fork do Einhorn::TransientState.whatami = :worker prepare_child_process Einhorn.log_info("About to exec #{cmd.inspect}") # Here's the only case where cloexec would help. Since we # have to track and manually close FDs for other cases, we # may as well just reuse close_all rather than also set # cloexec on everything. Einhorn::Event.close_all_for_worker prepare_child_environment exec [cmd[0], cmd[0]], *cmd[1..-1] end end Einhorn.log_info("===> Launched #{pid}") Einhorn::State.children[pid] = { :type => :worker, :version => Einhorn::State.version, :acked => false, :signaled => Set.new } Einhorn::State.last_spinup = Time.now # Set up whatever's needed for ACKing ack_mode = Einhorn::State.ack_mode case type = ack_mode[:type] when :timer Einhorn::Event::ACKTimer.open(ack_mode[:timeout], pid) when :manual else Einhorn.log_error("Unrecognized ACK mode #{type.inspect}") end end |
.upgrade_workers ⇒ Object
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# File 'lib/einhorn/command.rb', line 297 def self.upgrade_workers if Einhorn::State.upgrading Einhorn.log_info("Currently upgrading (#{Einhorn::WorkerPool.ack_count} / #{Einhorn::WorkerPool.ack_target} ACKs; bumping version and starting over)...") else Einhorn::State.upgrading = true Einhorn.log_info("Starting upgrade to #{Einhorn::State.version}...") end # Reset this, since we've just upgraded to a new universe (I'm # not positive this is the right behavior, but it's not # obviously wrong.) Einhorn::State.consecutive_deaths_before_ack = 0 Einhorn::State.last_upgraded = Time.now Einhorn::State.version += 1 replenish_immediately end |