correct some test concurrency bugs

lib/scheduler/manager.rb

@@ -8,7 +8,7 @@ require_dependency 'distributed_mutex'
 
 module Scheduler
   class Manager
-    attr_accessor :random_ratio, :redis
+    attr_accessor :random_ratio, :redis, :enable_stats
 
     class Runner
       def initialize(manager)
@@ -69,13 +69,15 @@ module Scheduler
         begin
           info.prev_result = "RUNNING"
           @mutex.synchronize { info.write! }
-          stat = SchedulerStat.create!(
-            name: klass.to_s,
-            hostname: hostname,
-            pid: Process.pid,
-            started_at: Time.zone.now,
-            live_slots_start: GC.stat[:heap_live_slots]
-          )
+          if @manager.enable_stats
+            stat = SchedulerStat.create!(
+              name: klass.to_s,
+              hostname: hostname,
+              pid: Process.pid,
+              started_at: Time.zone.now,
+              live_slots_start: GC.stat[:heap_live_slots]
+            )
+          end
           klass.new.perform
         rescue Jobs::HandledExceptionWrapper
           # Discourse.handle_exception was already called, and we don't have any extra info to give
@@ -88,11 +90,13 @@ module Scheduler
         info.prev_duration = duration
         info.prev_result = failed ? "FAILED" : "OK"
         info.current_owner = nil
-        stat.update_columns(
-          duration_ms: duration,
-          live_slots_finish: GC.stat[:heap_live_slots],
-          success: !failed
-        )
+        if stat
+          stat.update_columns(
+            duration_ms: duration,
+            live_slots_finish: GC.stat[:heap_live_slots],
+            success: !failed
+          )
+        end
         attempts(3) do
           @mutex.synchronize { info.write! }
         end
@@ -151,6 +155,12 @@ module Scheduler
 
       @hostname = options && options[:hostname]
       @manager_id = SecureRandom.hex
+
+      if options && options.key?(:enable_stats)
+        @enable_stats = options[:enable_stats]
+      else
+        @enable_stats = true
+      end
     end
 
     def self.current

spec/components/scheduler/manager_spec.rb

@@ -54,7 +54,9 @@ describe Scheduler::Manager do
     end
   end
 
-  let(:manager) { Scheduler::Manager.new(DiscourseRedis.new) }
+  let(:manager) {
+    Scheduler::Manager.new(DiscourseRedis.new, enable_stats: false)
+  }
 
   before do
     $redis.del manager.class.lock_key
@@ -79,7 +81,7 @@ describe Scheduler::Manager do
 
       hosts.map do |host|
 
-        manager = Scheduler::Manager.new(DiscourseRedis.new, hostname: host)
+        manager = Scheduler::Manager.new(DiscourseRedis.new, hostname: host, enable_stats: false)
         manager.ensure_schedule!(Testing::PerHostJob)
 
         info = manager.schedule_info(Testing::PerHostJob)
@@ -126,7 +128,7 @@ describe Scheduler::Manager do
 
       $redis.del manager.identity_key
 
-      manager = Scheduler::Manager.new(DiscourseRedis.new)
+      manager = Scheduler::Manager.new(DiscourseRedis.new, enable_stats: false)
       manager.reschedule_orphans!
 
       info = manager.schedule_info(Testing::SuperLongJob)
@@ -174,7 +176,7 @@ describe Scheduler::Manager do
 
       (0..5).map do
         Thread.new do
-          manager = Scheduler::Manager.new(DiscourseRedis.new)
+          manager = Scheduler::Manager.new(DiscourseRedis.new, enable_stats: false)
           manager.blocking_tick
           manager.stop!
         end