diff options
Diffstat (limited to 'config/initializers/stackprof.rb')
| -rw-r--r-- | config/initializers/stackprof.rb | 184 |
1 files changed, 106 insertions, 78 deletions
diff --git a/config/initializers/stackprof.rb b/config/initializers/stackprof.rb index 5497ff9a459..797efdb9bbd 100644 --- a/config/initializers/stackprof.rb +++ b/config/initializers/stackprof.rb @@ -8,94 +8,122 @@ # * timeout profile after 30 seconds # * write to $TMPDIR/stackprof.$PID.$RAND.profile -if Gitlab::Utils.to_boolean(ENV['STACKPROF_ENABLED'].to_s) - Gitlab::Cluster::LifecycleEvents.on_worker_start do - require 'stackprof' - require 'tmpdir' +module Gitlab + class StackProf + # this is a workaround for sidekiq, which defines its own SIGUSR2 handler. + # by defering to the sidekiq startup event, we get to set up our own + # handler late enough. + # see also: https://github.com/mperham/sidekiq/pull/4653 + def self.install + require 'stackprof' + require 'tmpdir' + + if Gitlab::Runtime.sidekiq? + Sidekiq.configure_server do |config| + config.on :startup do + on_worker_start + end + end + else + Gitlab::Cluster::LifecycleEvents.on_worker_start do + on_worker_start + end + end + end - Gitlab::AppJsonLogger.info "stackprof: listening on SIGUSR2 signal" + def self.on_worker_start + Gitlab::AppJsonLogger.info( + event: "stackprof", + message: "listening on SIGUSR2 signal", + pid: Process.pid + ) - # create a pipe in order to propagate signal out of the signal handler - # see also: https://cr.yp.to/docs/selfpipe.html - read, write = IO.pipe + # create a pipe in order to propagate signal out of the signal handler + # see also: https://cr.yp.to/docs/selfpipe.html + read, write = IO.pipe - # create a separate thread that polls for signals on the pipe. - # - # this way we do not execute in signal handler context, which - # lifts restrictions and also serializes the calls in a thread-safe - # manner. - # - # it's very similar to a goroutine and channel design. - # - # another nice benefit of this method is that we can timeout the - # IO.select call, allowing the profile to automatically stop after - # a given interval (by default 30 seconds), avoiding unbounded memory - # growth from a profile that was started and never stopped. - t = Thread.new do - timeout_s = ENV['STACKPROF_TIMEOUT_S']&.to_i || 30 - current_timeout_s = nil - loop do - got_value = IO.select([read], nil, nil, current_timeout_s) - read.getbyte if got_value + # create a separate thread that polls for signals on the pipe. + # + # this way we do not execute in signal handler context, which + # lifts restrictions and also serializes the calls in a thread-safe + # manner. + # + # it's very similar to a goroutine and channel design. + # + # another nice benefit of this method is that we can timeout the + # IO.select call, allowing the profile to automatically stop after + # a given interval (by default 30 seconds), avoiding unbounded memory + # growth from a profile that was started and never stopped. + t = Thread.new do + timeout_s = ENV['STACKPROF_TIMEOUT_S']&.to_i || 30 + current_timeout_s = nil + loop do + got_value = IO.select([read], nil, nil, current_timeout_s) + read.getbyte if got_value - if StackProf.running? - stackprof_file_prefix = ENV['STACKPROF_FILE_PREFIX'] || Dir.tmpdir - stackprof_out_file = "#{stackprof_file_prefix}/stackprof.#{Process.pid}.#{SecureRandom.hex(6)}.profile" + if ::StackProf.running? + stackprof_file_prefix = ENV['STACKPROF_FILE_PREFIX'] || Dir.tmpdir + stackprof_out_file = "#{stackprof_file_prefix}/stackprof.#{Process.pid}.#{SecureRandom.hex(6)}.profile" - Gitlab::AppJsonLogger.info( - event: "stackprof", - message: "stopping profile", - output_filename: stackprof_out_file, - pid: Process.pid, - timeout_s: timeout_s, - timed_out: got_value.nil? - ) + Gitlab::AppJsonLogger.info( + event: "stackprof", + message: "stopping profile", + output_filename: stackprof_out_file, + pid: Process.pid, + timeout_s: timeout_s, + timed_out: got_value.nil? + ) - StackProf.stop - StackProf.results(stackprof_out_file) - current_timeout_s = nil - else - Gitlab::AppJsonLogger.info( - event: "stackprof", - message: "starting profile", - pid: Process.pid - ) + ::StackProf.stop + ::StackProf.results(stackprof_out_file) + current_timeout_s = nil + else + Gitlab::AppJsonLogger.info( + event: "stackprof", + message: "starting profile", + pid: Process.pid + ) - StackProf.start( - mode: :cpu, - raw: Gitlab::Utils.to_boolean(ENV['STACKPROF_RAW'] || 'true'), - interval: ENV['STACKPROF_INTERVAL_US']&.to_i || 10_000 - ) - current_timeout_s = timeout_s + ::StackProf.start( + mode: :cpu, + raw: Gitlab::Utils.to_boolean(ENV['STACKPROF_RAW'] || 'true'), + interval: ENV['STACKPROF_INTERVAL_US']&.to_i || 10_000 + ) + current_timeout_s = timeout_s + end end end - end - t.abort_on_exception = true + t.abort_on_exception = true - # in the case of puma, this will override the existing SIGUSR2 signal handler - # that can be used to trigger a restart. - # - # puma cluster has two types of restarts: - # * SIGUSR1: phased restart - # * SIGUSR2: restart - # - # phased restart is not supported in our configuration, because we use - # preload_app. this means we will always perform a normal restart. - # additionally, phased restart is not supported when sending a SIGUSR2 - # directly to a puma worker (as opposed to the master process). - # - # the result is that the behaviour of SIGUSR1 and SIGUSR2 is identical in - # our configuration, and we can always use a SIGUSR1 to perform a restart. - # - # thus, it is acceptable for us to re-appropriate the SIGUSR2 signal, and - # override the puma behaviour. - # - # see also: - # * https://github.com/puma/puma/blob/master/docs/signals.md#puma-signals - # * https://github.com/phusion/unicorn/blob/master/SIGNALS - # * https://github.com/mperham/sidekiq/wiki/Signals - Signal.trap('SIGUSR2') do - write.write('.') + # in the case of puma, this will override the existing SIGUSR2 signal handler + # that can be used to trigger a restart. + # + # puma cluster has two types of restarts: + # * SIGUSR1: phased restart + # * SIGUSR2: restart + # + # phased restart is not supported in our configuration, because we use + # preload_app. this means we will always perform a normal restart. + # additionally, phased restart is not supported when sending a SIGUSR2 + # directly to a puma worker (as opposed to the master process). + # + # the result is that the behaviour of SIGUSR1 and SIGUSR2 is identical in + # our configuration, and we can always use a SIGUSR1 to perform a restart. + # + # thus, it is acceptable for us to re-appropriate the SIGUSR2 signal, and + # override the puma behaviour. + # + # see also: + # * https://github.com/puma/puma/blob/master/docs/signals.md#puma-signals + # * https://github.com/phusion/unicorn/blob/master/SIGNALS + # * https://github.com/mperham/sidekiq/wiki/Signals + Signal.trap('SIGUSR2') do + write.write('.') + end end end end + +if Gitlab::Utils.to_boolean(ENV['STACKPROF_ENABLED'].to_s) + Gitlab::StackProf.install +end |