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: Ib03ad48060349921b94fc4c794b3e02f41ad979d

manifests/wsgi/apache.pp

@@ -50,7 +50,7 @@
 #
 #   [*threads*]
 #     (optional) The number of threads for the vhost.
-#     Defaults to $::processorcount
+#     Defaults to $::os_workers
 #
 #   [*ssl_cert*]
 #   [*ssl_key*]
@@ -87,7 +87,7 @@ class ironic::wsgi::apache (
   $ssl_crl_path  = undef,
   $ssl_crl       = undef,
   $ssl_certs_dir = undef,
-  $threads       = $::processorcount,
+  $threads       = $::os_workers,
   $priority      = '10',
 ) {
 

releasenotes/notes/os_workers_for_worker_count-24578f84123bd2ea.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/ironic_api_spec.rb

@@ -145,7 +145,6 @@ describe 'ironic::api' do
         :operatingsystemrelease => '8.0',
         :concat_basedir  => '/var/lib/puppet/concat',
         :fqdn            => 'some.host.tld',
-        :processorcount  => 2,
       })
     end
 
@@ -165,7 +164,6 @@ describe 'ironic::api' do
         :operatingsystemrelease => '7.2',
         :concat_basedir         => '/var/lib/puppet/concat',
         :fqdn                   => 'some.host.tld',
-        :processorcount         => 2,
       })
     end
 

spec/classes/ironic_db_postgresql_spec.rb

@@ -30,7 +30,7 @@ describe 'ironic::db::postgresql' do
     context "on #{os}" do
       let (:facts) do
         facts.merge(OSDefaults.get_facts({
-          :processorcount => 8,
+          :os_workers     => 8,
           :concat_basedir => '/var/lib/puppet/concat'
         }))
       end

spec/classes/ironic_db_sync_spec.rb

@@ -37,7 +37,7 @@ describe 'ironic::db::sync' do
     context "on #{os}" do
       let (:facts) do
         facts.merge(OSDefaults.get_facts({
-          :processorcount => 8,
+          :os_workers     => 8,
           :concat_basedir => '/var/lib/puppet/concat'
         }))
       end

spec/classes/ironic_wsgi_apache_spec.rb

@@ -4,7 +4,7 @@ describe 'ironic::wsgi::apache' do
 
   let :global_facts do
     OSDefaults.get_facts({
-      :processorcount => 42,
+      :os_workers     => 8,
       :concat_basedir => '/var/lib/puppet/concat',
       :fqdn           => 'some.host.tld'
     })