Merge "Cap the number of worker threads"

defaults/main.yml

@@ -125,6 +125,10 @@ horizon_disallow_iframe_embed: True
 # horizon_wsgi_processes: 4
 # horizon_wsgi_threads: 4
 
+## Cap the maximun number of threads / workers when a user value is unspecified.
+horizon_wsgi_threads_max: 16
+horizon_wsgi_threads: "{{ [[ansible_processor_vcpus|default(2) // 2, 1] | max, horizon_wsgi_threads_max] | min }}"
+
 ## Horizon SSL
 horizon_ssl_cert: /etc/ssl/certs/horizon.pem
 horizon_ssl_key: /etc/ssl/private/horizon.key

releasenotes/notes/capping_horizon_workers-29ecc4893bcc3a4b.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - Capping the default value for the variables
+    ``horizon_wsgi_processes`` and ``horizon_wsgi_threads`` to 16 when the
+    user doesn't configure these variables. Default value is half the number
+    of vCPUs available on the machine with a capping value of 16.

templates/openstack_dashboard.conf.j2

@@ -1,8 +1,5 @@
 # {{ ansible_managed }}
 
-{% set _wsgi_threads = ansible_processor_vcpus | default(2) // 2 %}
-{% set wsgi_threads = _wsgi_threads if _wsgi_threads > 0 else 1 %}
-
 {% if not horizon_external_ssl | bool %}
 <VirtualHost *:80>
     ServerName {{ horizon_server_name }}
@@ -36,7 +33,7 @@
 {% endif %}
 
     WSGIScriptAlias / {{ horizon_lib_wsgi_file }}
-    WSGIDaemonProcess horizon user={{ horizon_system_user_name }} group={{ horizon_system_group_name }} processes={{ horizon_wsgi_processes | default(wsgi_threads) }} threads={{ horizon_wsgi_threads | default(wsgi_threads) }} python-path={{ horizon_bin | dirname }}/lib/python2.7/site-packages
+    WSGIDaemonProcess horizon user={{ horizon_system_user_name }} group={{ horizon_system_group_name }} processes={{ horizon_wsgi_processes | default(horizon_wsgi_threads) }} threads={{ horizon_wsgi_threads }} python-path={{ horizon_bin | dirname }}/lib/python2.7/site-packages
 
     WSGIProcessGroup horizon
     WSGIApplicationGroup horizon