Revert "Restart Unicorn and Sidekiq when GRPC throws 14:Endpoint read failed"

This reverts commit 00675311.

config/initializers/sidekiq.rb

@@ -22,7 +22,7 @@ Sidekiq.configure_server do |config|
 
   config.server_middleware do |chain|
     chain.add Gitlab::SidekiqMiddleware::ArgumentsLogger if ENV['SIDEKIQ_LOG_ARGUMENTS'] && !enable_json_logs
-    chain.add Gitlab::SidekiqMiddleware::Shutdown
+    chain.add Gitlab::SidekiqMiddleware::MemoryKiller if ENV['SIDEKIQ_MEMORY_KILLER_MAX_RSS']
     chain.add Gitlab::SidekiqMiddleware::RequestStoreMiddleware unless ENV['SIDEKIQ_REQUEST_STORE'] == '0'
     chain.add Gitlab::SidekiqMiddleware::BatchLoader
     chain.add Gitlab::SidekiqMiddleware::CorrelationLogger

lib/gitlab/gitaly_client.rb

@@ -164,8 +164,6 @@ module Gitlab
       kwargs = yield(kwargs) if block_given?
 
       stub(service, storage).__send__(rpc, request, kwargs) # rubocop:disable GitlabSecurity/PublicSend
-    rescue GRPC::Unavailable => ex
-      handle_grpc_unavailable!(ex)
     ensure
       duration = Gitlab::Metrics::System.monotonic_time - start
 
@@ -178,27 +176,6 @@ module Gitlab
       add_call_details(feature: "#{service}##{rpc}", duration: duration, request: request_hash, rpc: rpc)
     end
 
-    def self.handle_grpc_unavailable!(ex)
-      status = ex.to_status
-      raise ex unless status.details == 'Endpoint read failed'
-
-      # There is a bug in grpc 1.8.x that causes a client process to get stuck
-      # always raising '14:Endpoint read failed'. The only thing that we can
-      # do to recover is to restart the process.
-      #
-      # See https://gitlab.com/gitlab-org/gitaly/issues/1029
-
-      if Sidekiq.server?
-        raise Gitlab::SidekiqMiddleware::Shutdown::WantShutdown.new(ex.to_s)
-      else
-        # SIGQUIT requests a Unicorn worker to shut down gracefully after the current request.
-        Process.kill('QUIT', Process.pid)
-      end
-
-      raise ex
-    end
-    private_class_method :handle_grpc_unavailable!
-
     def self.current_transaction_labels
       Gitlab::Metrics::Transaction.current&.labels || {}
     end

lib/gitlab/sidekiq_middleware/memory_killer.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module SidekiqMiddleware
+    class MemoryKiller
+      # Default the RSS limit to 0, meaning the MemoryKiller is disabled
+      MAX_RSS = (ENV['SIDEKIQ_MEMORY_KILLER_MAX_RSS'] || 0).to_s.to_i
+      # Give Sidekiq 15 minutes of grace time after exceeding the RSS limit
+      GRACE_TIME = (ENV['SIDEKIQ_MEMORY_KILLER_GRACE_TIME'] || 15 * 60).to_s.to_i
+      # Wait 30 seconds for running jobs to finish during graceful shutdown
+      SHUTDOWN_WAIT = (ENV['SIDEKIQ_MEMORY_KILLER_SHUTDOWN_WAIT'] || 30).to_s.to_i
+
+      # Create a mutex used to ensure there will be only one thread waiting to
+      # shut Sidekiq down
+      MUTEX = Mutex.new
+
+      def call(worker, job, queue)
+        yield
+
+        current_rss = get_rss
+
+        return unless MAX_RSS > 0 && current_rss > MAX_RSS
+
+        Thread.new do
+          # Return if another thread is already waiting to shut Sidekiq down
+          next unless MUTEX.try_lock
+
+          Sidekiq.logger.warn "Sidekiq worker PID-#{pid} current RSS #{current_rss}"\
+            " exceeds maximum RSS #{MAX_RSS} after finishing job #{worker.class} JID-#{job['jid']}"
+          Sidekiq.logger.warn "Sidekiq worker PID-#{pid} will stop fetching new jobs in #{GRACE_TIME} seconds, and will be shut down #{SHUTDOWN_WAIT} seconds later"
+
+          # Wait `GRACE_TIME` to give the memory intensive job time to finish.
+          # Then, tell Sidekiq to stop fetching new jobs.
+          wait_and_signal(GRACE_TIME, 'SIGSTP', 'stop fetching new jobs')
+
+          # Wait `SHUTDOWN_WAIT` to give already fetched jobs time to finish.
+          # Then, tell Sidekiq to gracefully shut down by giving jobs a few more
+          # moments to finish, killing and requeuing them if they didn't, and
+          # then terminating itself.
+          wait_and_signal(SHUTDOWN_WAIT, 'SIGTERM', 'gracefully shut down')
+
+          # Wait for Sidekiq to shutdown gracefully, and kill it if it didn't.
+          wait_and_signal(Sidekiq.options[:timeout] + 2, 'SIGKILL', 'die')
+        end
+      end
+
+      private
+
+      def get_rss
+        output, status = Gitlab::Popen.popen(%W(ps -o rss= -p #{pid}), Rails.root.to_s)
+        return 0 unless status.zero?
+
+        output.to_i
+      end
+
+      def wait_and_signal(time, signal, explanation)
+        Sidekiq.logger.warn "waiting #{time} seconds before sending Sidekiq worker PID-#{pid} #{signal} (#{explanation})"
+        sleep(time)
+
+        Sidekiq.logger.warn "sending Sidekiq worker PID-#{pid} #{signal} (#{explanation})"
+        Process.kill(signal, pid)
+      end
+
+      def pid
+        Process.pid
+      end
+    end
+  end
+end

lib/gitlab/sidekiq_middleware/shutdown.rb

-# frozen_string_literal: true
-
-require 'mutex_m'
-
-module Gitlab
-  module SidekiqMiddleware
-    class Shutdown
-      extend Mutex_m
-
-      # Default the RSS limit to 0, meaning the MemoryKiller is disabled
-      MAX_RSS = (ENV['SIDEKIQ_MEMORY_KILLER_MAX_RSS'] || 0).to_s.to_i
-      # Give Sidekiq 15 minutes of grace time after exceeding the RSS limit
-      GRACE_TIME = (ENV['SIDEKIQ_MEMORY_KILLER_GRACE_TIME'] || 15 * 60).to_s.to_i
-      # Wait 30 seconds for running jobs to finish during graceful shutdown
-      SHUTDOWN_WAIT = (ENV['SIDEKIQ_MEMORY_KILLER_SHUTDOWN_WAIT'] || 30).to_s.to_i
-
-      # This exception can be used to request that the middleware start shutting down Sidekiq
-      WantShutdown = Class.new(StandardError)
-
-      ShutdownWithoutRaise = Class.new(WantShutdown)
-      private_constant :ShutdownWithoutRaise
-
-      # For testing only, to avoid race conditions (?) in Rspec mocks.
-      attr_reader :trace
-
-      # We store the shutdown thread in a class variable to ensure that there
-      # can be only one shutdown thread in the process.
-      def self.create_shutdown_thread
-        mu_synchronize do
-          break unless @shutdown_thread.nil?
-
-          @shutdown_thread = Thread.new { yield }
-        end
-      end
-
-      # For testing only: so we can wait for the shutdown thread to finish.
-      def self.shutdown_thread
-        mu_synchronize { @shutdown_thread }
-      end
-
-      # For testing only: so that we can reset the global state before each test.
-      def self.clear_shutdown_thread
-        mu_synchronize { @shutdown_thread = nil }
-      end
-
-      def initialize
-        @trace = Queue.new if Rails.env.test?
-      end
-
-      def call(worker, job, queue)
-        shutdown_exception = nil
-
-        begin
-          yield
-          check_rss!
-        rescue WantShutdown => ex
-          shutdown_exception = ex
-        end
-
-        return unless shutdown_exception
-
-        self.class.create_shutdown_thread do
-          do_shutdown(worker, job, shutdown_exception)
-        end
-
-        raise shutdown_exception unless shutdown_exception.is_a?(ShutdownWithoutRaise)
-      end
-
-      private
-
-      def do_shutdown(worker, job, shutdown_exception)
-        Sidekiq.logger.warn "Sidekiq worker PID-#{pid} shutting down because of #{shutdown_exception} after job "\
-          "#{worker.class} JID-#{job['jid']}"
-        Sidekiq.logger.warn "Sidekiq worker PID-#{pid} will stop fetching new jobs in #{GRACE_TIME} seconds, and will be shut down #{SHUTDOWN_WAIT} seconds later"
-
-        # Wait `GRACE_TIME` to give the memory intensive job time to finish.
-        # Then, tell Sidekiq to stop fetching new jobs.
-        wait_and_signal(GRACE_TIME, 'SIGTSTP', 'stop fetching new jobs')
-
-        # Wait `SHUTDOWN_WAIT` to give already fetched jobs time to finish.
-        # Then, tell Sidekiq to gracefully shut down by giving jobs a few more
-        # moments to finish, killing and requeuing them if they didn't, and
-        # then terminating itself.
-        wait_and_signal(SHUTDOWN_WAIT, 'SIGTERM', 'gracefully shut down')
-
-        # Wait for Sidekiq to shutdown gracefully, and kill it if it didn't.
-        wait_and_signal(Sidekiq.options[:timeout] + 2, 'SIGKILL', 'die')
-      end
-
-      def check_rss!
-        return unless MAX_RSS > 0
-
-        current_rss = get_rss
-        return unless current_rss > MAX_RSS
-
-        raise ShutdownWithoutRaise.new("current RSS #{current_rss} exceeds maximum RSS #{MAX_RSS}")
-      end
-
-      def get_rss
-        output, status = Gitlab::Popen.popen(%W(ps -o rss= -p #{pid}), Rails.root.to_s)
-        return 0 unless status.zero?
-
-        output.to_i
-      end
-
-      def wait_and_signal(time, signal, explanation)
-        Sidekiq.logger.warn "waiting #{time} seconds before sending Sidekiq worker PID-#{pid} #{signal} (#{explanation})"
-        sleep(time)
-
-        Sidekiq.logger.warn "sending Sidekiq worker PID-#{pid} #{signal} (#{explanation})"
-        kill(signal, pid)
-      end
-
-      def pid
-        Process.pid
-      end
-
-      def sleep(time)
-        if Rails.env.test?
-          @trace << [:sleep, time]
-        else
-          Kernel.sleep(time)
-        end
-      end
-
-      def kill(signal, pid)
-        if Rails.env.test?
-          @trace << [:kill, signal, pid]
-        else
-          Process.kill(signal, pid)
-        end
-      end
-    end
-  end
-end

spec/lib/gitlab/sidekiq_middleware/shutdown_spec.rb → spec/lib/gitlab/sidekiq_middleware/memory_killer_spec.rb

 require 'spec_helper'
 
-describe Gitlab::SidekiqMiddleware::Shutdown do
+describe Gitlab::SidekiqMiddleware::MemoryKiller do
   subject { described_class.new }
+  let(:pid) { 999 }
 
-  let(:pid) { Process.pid }
   let(:worker) { double(:worker, class: 'TestWorker') }
   let(:job) { { 'jid' => 123 } }
   let(:queue) { 'test_queue' }
-  let(:block) { proc { nil } }
 
   def run
-    subject.call(worker, job, queue) { block.call }
-    described_class.shutdown_thread&.join
-  end
-
-  def pop_trace
-    subject.trace.pop(true)
+    thread = subject.call(worker, job, queue) { nil }
+    thread&.join
   end
 
   before do
     allow(subject).to receive(:get_rss).and_return(10.kilobytes)
-    described_class.clear_shutdown_thread
+    allow(subject).to receive(:pid).and_return(pid)
   end
 
   context 'when MAX_RSS is set to 0' do
@@ -35,26 +30,22 @@ describe Gitlab::SidekiqMiddleware::Shutdown do
     end
   end
 
-  def expect_shutdown_sequence
-    expect(pop_trace).to eq([:sleep, 15 * 60])
-    expect(pop_trace).to eq([:kill, 'SIGTSTP', pid])
-
-    expect(pop_trace).to eq([:sleep, 30])
-    expect(pop_trace).to eq([:kill, 'SIGTERM', pid])
-
-    expect(pop_trace).to eq([:sleep, 10])
-    expect(pop_trace).to eq([:kill, 'SIGKILL', pid])
-  end
-
   context 'when MAX_RSS is exceeded' do
     before do
       stub_const("#{described_class}::MAX_RSS", 5.kilobytes)
     end
 
-    it 'sends the TSTP, TERM and KILL signals at expected times' do
-      run
+    it 'sends the STP, TERM and KILL signals at expected times' do
+      expect(subject).to receive(:sleep).with(15 * 60).ordered
+      expect(Process).to receive(:kill).with('SIGSTP', pid).ordered
+
+      expect(subject).to receive(:sleep).with(30).ordered
+      expect(Process).to receive(:kill).with('SIGTERM', pid).ordered
 
-      expect_shutdown_sequence
+      expect(subject).to receive(:sleep).with(10).ordered
+      expect(Process).to receive(:kill).with('SIGKILL', pid).ordered
+
+      run
     end
   end
 
@@ -69,20 +60,4 @@ describe Gitlab::SidekiqMiddleware::Shutdown do
       run
     end
   end
-
-  context 'when WantShutdown is raised' do
-    let(:block) { proc { raise described_class::WantShutdown } }
-
-    it 'starts the shutdown sequence and re-raises the exception' do
-      expect { run }.to raise_exception(described_class::WantShutdown)
-
-      # We can't expect 'run' to have joined on the shutdown thread, because
-      # it hit an exception.
-      shutdown_thread = described_class.shutdown_thread
-      expect(shutdown_thread).not_to be_nil
-      shutdown_thread.join
-
-      expect_shutdown_sequence
-    end
-  end
 end