110 lines
3 KiB
Ruby
110 lines
3 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
module Gitlab
|
|
module Cluster
|
|
#
|
|
# LifecycleEvents lets Rails initializers register application startup hooks
|
|
# that are sensitive to forking. For example, to defer the creation of
|
|
# watchdog threads. This lets us abstract away the Unix process
|
|
# lifecycles of Unicorn, Sidekiq, Puma, Puma Cluster, etc.
|
|
#
|
|
# We have three lifecycle events.
|
|
#
|
|
# - before_fork (only in forking processes)
|
|
# In forking processes (Unicorn and Puma in multiprocess mode) this
|
|
# will be called exactly once, on startup, before the workers are
|
|
# forked. This will be called in the parent process.
|
|
# - worker_start
|
|
# - before_master_restart (only in forking processes)
|
|
#
|
|
# Blocks will be executed in the order in which they are registered.
|
|
#
|
|
class LifecycleEvents
|
|
class << self
|
|
#
|
|
# Hook registration methods (called from initializers)
|
|
#
|
|
def on_worker_start(&block)
|
|
if in_clustered_environment?
|
|
# Defer block execution
|
|
(@worker_start_hooks ||= []) << block
|
|
else
|
|
yield
|
|
end
|
|
end
|
|
|
|
def on_before_fork(&block)
|
|
return unless in_clustered_environment?
|
|
|
|
# Defer block execution
|
|
(@before_fork_hooks ||= []) << block
|
|
end
|
|
|
|
def on_master_restart(&block)
|
|
return unless in_clustered_environment?
|
|
|
|
# Defer block execution
|
|
(@master_restart_hooks ||= []) << block
|
|
end
|
|
|
|
def on_master_start(&block)
|
|
if in_clustered_environment?
|
|
on_before_fork(&block)
|
|
else
|
|
on_worker_start(&block)
|
|
end
|
|
end
|
|
|
|
#
|
|
# Lifecycle integration methods (called from unicorn.rb, puma.rb, etc.)
|
|
#
|
|
def do_worker_start
|
|
@worker_start_hooks&.each do |block|
|
|
block.call
|
|
end
|
|
end
|
|
|
|
def do_before_fork
|
|
@before_fork_hooks&.each do |block|
|
|
block.call
|
|
end
|
|
end
|
|
|
|
def do_master_restart
|
|
@master_restart_hooks && @master_restart_hooks.each do |block|
|
|
block.call
|
|
end
|
|
end
|
|
|
|
# Puma doesn't use singletons (which is good) but
|
|
# this means we need to pass through whether the
|
|
# puma server is running in single mode or cluster mode
|
|
def set_puma_options(options)
|
|
@puma_options = options
|
|
end
|
|
|
|
private
|
|
|
|
def in_clustered_environment?
|
|
# Sidekiq doesn't fork
|
|
return false if Sidekiq.server?
|
|
|
|
# Unicorn always forks
|
|
return true if defined?(::Unicorn)
|
|
|
|
# Puma sometimes forks
|
|
return true if in_clustered_puma?
|
|
|
|
# Default assumption is that we don't fork
|
|
false
|
|
end
|
|
|
|
def in_clustered_puma?
|
|
return false unless defined?(::Puma)
|
|
|
|
@puma_options && @puma_options[:workers] && @puma_options[:workers] > 0
|
|
end
|
|
end
|
|
end
|
|
end
|
|
end
|