Change worker defaults to ::os_workers

This patch changes the default worker count from ::processorcount to the
new ::os_workers fact. ::os_workers is based on the number of processors
(currently cpu/4) but is capped at a maximum of 8 worker processors.
This is a much more reasonable default in general and prevents excessive
resource consumption on systems with a large number of CPUs.

Change-Id: I3808177027a880c88f075cdbef0aba2a56fb26bc

manifests/api.pp

@@ -27,7 +27,7 @@
 #
 # [*workers*]
 #   (optional) Number of Glance API worker processes to start
-#   Default: $::processorcount
+#   Default: $::os_workers.
 #
 # [*log_file*]
 #   (optional) The path of file used for logging
@@ -320,7 +320,7 @@ class glance::api(
   $bind_host                            = $::os_service_default,
   $bind_port                            = '9292',
   $backlog                              = $::os_service_default,
-  $workers                              = $::processorcount,
+  $workers                              = $::os_workers,
   $log_file                             = undef,
   $log_dir                              = undef,
   $registry_host                        = '0.0.0.0',

manifests/glare.pp

@@ -23,7 +23,7 @@
 #
 # [*workers*]
 #   (optional) Number of Glance Glare worker processes to start
-#   Default: $::processorcount
+#   Default: $::os_workers.
 #
 # [*auth_strategy*]
 #   (optional) Type is authorization being used.
@@ -134,7 +134,7 @@ class glance::glare(
   $bind_host                 = '0.0.0.0',
   $bind_port                 = '9494',
   $backlog                   = '4096',
-  $workers                   = $::processorcount,
+  $workers                   = $::os_workers,
   $auth_strategy             = 'keystone',
   $pipeline                  = 'keystone',
   $manage_service            = true,

manifests/registry.pp

@@ -22,7 +22,7 @@
 #  [*workers*]
 #    (optional) The number of child process workers that will be
 #    created to service Registry requests.
-#    Defaults to: $::processorcount
+#    Defaults to: $::os_workers.
 #
 #  [*log_file*]
 #    (optional) Log file for glance-registry.
@@ -174,7 +174,7 @@ class glance::registry(
   $debug                   = undef,
   $bind_host               = $::os_service_default,
   $bind_port               = '9191',
-  $workers                 = $::processorcount,
+  $workers                 = $::os_workers,
   $log_file                = undef,
   $log_dir                 = undef,
   $database_connection     = undef,

releasenotes/notes/os_workers_for_worker_count-f86aa67474d5cac9.yaml

@@ -0,0 +1,5 @@
+---
+other:
+  - Parameters that control the number of spawned child processes for
+    distributing processing have had their default value changed from
+    ::processorcount to ::os_workers.

spec/classes/glance_registry_spec.rb

@@ -7,7 +7,7 @@ describe 'glance::registry' do
       :use_stderr             => '<SERVICE DEFAULT>',
       :bind_host              => '<SERVICE DEFAULT>',
       :bind_port              => '9191',
-      :workers                => facts[:processorcount],
+      :workers                => facts[:os_workers],
       :log_file               => '/var/log/glance/registry.log',
       :log_dir                => '/var/log/glance',
       :enabled                => true,