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: Iae9e5c6e5a5f68cb7f0a0dfc0edb0d21912cda19

manifests/api.pp

@@ -20,7 +20,7 @@
 #
 # [*workers*]
 #   (optional) Number of workers for Gnocchi API server.
-#   Defaults to $::processorcount
+#   Defaults to $::os_workers
 #
 # [*max_limit*]
 #   (optional) The maximum number of items returned in a
@@ -83,7 +83,7 @@ class gnocchi::api (
   $package_ensure               = 'present',
   $host                         = '0.0.0.0',
   $port                         = '8041',
-  $workers                      = $::processorcount,
+  $workers                      = $::os_workers,
   $max_limit                    = 1000,
   $service_name                 = $::gnocchi::params::api_service_name,
   $sync_db                      = false,

manifests/wsgi/apache.pp

@@ -46,7 +46,7 @@
 #
 #   [*workers*]
 #     Number of WSGI workers to spawn.
-#     Optional. Defaults to max(($::processorcount + 0)/4, 2)
+#     Optional. Defaults to $::os_workers
 #
 #   [*priority*]
 #     (optional) The priority for the vhost.
@@ -82,7 +82,7 @@ class gnocchi::wsgi::apache (
   $bind_host     = undef,
   $path          = '/',
   $ssl           = true,
-  $workers       = max(($::processorcount + 0)/4, 2),
+  $workers       = $::os_workers,
   $ssl_cert      = undef,
   $ssl_key       = undef,
   $ssl_chain     = undef,

releasenotes/notes/os_workers_for_worker_count-3517788058682645.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/gnocchi_api_spec.rb

@@ -160,7 +160,6 @@ describe 'gnocchi::api' do
       let (:facts) do
         facts.merge!(OSDefaults.get_facts({
           :concat_basedir => '/var/lib/puppet/concat',
-          :processorcount => 2
         }))
       end
 

spec/classes/gnocchi_db_sync_spec.rb

@@ -36,7 +36,7 @@ describe 'gnocchi::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/gnocchi_wsgi_apache_spec.rb

@@ -57,7 +57,7 @@ describe 'gnocchi::wsgi::apache' do
           :bind_host   => '10.42.51.1',
           :port        => 12345,
           :ssl         => false,
-          :workers     => 37,
+          :workers     => 8,
           :threads     => 2,
         }
       end
@@ -73,7 +73,7 @@ describe 'gnocchi::wsgi::apache' do
         'wsgi_daemon_process_options' => {
           'user'      => 'gnocchi',
           'group'     => 'gnocchi',
-          'processes' => '37',
+          'processes' => '8',
           'threads'   => '2',
         },
         'wsgi_daemon_process'         => 'gnocchi',
@@ -92,7 +92,7 @@ describe 'gnocchi::wsgi::apache' do
     context "on #{os}" do
       let (:facts) do
         facts.merge!(OSDefaults.get_facts({
-          :processorcount => 16,
+          :os_workers     => 4,
           :concat_basedir => '/var/lib/puppet/concat',
           :fqdn           => 'some.host.tld',
         }))