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: Id7c5f3df32b4f350d93ed85b6293fe69e64c2cc3

manifests/wsgi/apache.pp

@@ -54,7 +54,7 @@
 #
 #   [*threads*]
 #     (optional) The number of threads for the vhost.
-#     Defaults to $::processorcount
+#     Defaults to $::os_workers
 #
 #   [*ssl_cert*]
 #   [*ssl_key*]
@@ -90,7 +90,7 @@ class aodh::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-d1ea2ef2beb0d686.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/aodh_api_spec.rb

@@ -189,7 +189,6 @@ describe 'aodh::api' do
       let (:facts) do
         facts.merge!(OSDefaults.get_facts({
           :fqdn           => 'some.host.tld',
-          :processorcount => 2,
           :concat_basedir => '/var/lib/puppet/concat'
         }))
       end

spec/classes/aodh_db_sync_spec.rb

@@ -22,7 +22,7 @@ describe 'aodh::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/aodh_evaluator_spec.rb

@@ -90,7 +90,6 @@ describe 'aodh::evaluator' do
       let (:facts) do
         facts.merge!(OSDefaults.get_facts({
           :fqdn           => 'some.host.tld',
-          :processorcount => 2,
           :concat_basedir => '/var/lib/puppet/concat'
         }))
       end

spec/classes/aodh_wsgi_apache_spec.rb

@@ -79,7 +79,7 @@ describe 'aodh::wsgi::apache' do
     context "on #{os}" do
       let (:facts) do
         facts.merge!(OSDefaults.get_facts({
-          :processorcount => 42,
+          :os_workers     => 8,
           :concat_basedir => '/var/lib/puppet/concat',
           :fqdn           => 'some.host.tld'
         }))