Increase the number of possible child processes

The mirrorlist-server is the process which has the mirrorlist data
loaded and which is accessed by the public facing
mirrorlist_client.wsgi. The mirrorlist-server uses the
ForkingUnixStreamServer which has a default of max_children = 40.
(https://hg.python.org/cpython/file/2.7/Lib/SocketServer.py#l516)

Looking at the code of ForkingUnixStreamServer it says at

https://hg.python.org/cpython/file/2.7/Lib/SocketServer.py#l523

  # If we're above the max number of children, wait and reap them until
  # we go back below threshold. Note that we use waitpid(-1) below to be
  # able to collect children in size(<defunct children>) syscalls instead
  # of size(<children>): the downside is that this might reap children
  # which we didn't spawn, which is why we only resort to this when we're
  # above max_children.

As we are running the wsgi with processes=45 this sounds like it can
lead to situation where it might just hang.

This increases max_children to 80 and processes to 60.

Signed-off-by: Adrian Reber <adrian@lisas.de>

files/hotfix/mirrorlist/mirrorlist_server.py

@@ -938,6 +938,7 @@ def sigterm_handler(signum, frame):
 
 class ForkingUnixStreamServer(ForkingMixIn, UnixStreamServer):
     request_queue_size = 300
+    max_children = 80
     def finish_request(self, request, client_address):
         signal.signal(signal.SIGHUP, signal.SIG_IGN)
         BaseServer.finish_request(self, request, client_address)

inventory/group_vars/mirrorlist2

@@ -23,7 +23,7 @@ fas_client_groups: sysadmin-noc,fi-apprentice
 nrpe_procs_warn: 500
 nrpe_procs_crit: 600
 # By default run 45 wsgi procs
-mirrorlist_procs: 45
+mirrorlist_procs: 60
 
 # Set this to get the vpn postfix setup
 postfix_group: vpn

inventory/group_vars/mirrorlist2-stg

@@ -14,7 +14,7 @@ fas_client_groups: sysadmin-noc,fi-apprentice,sysadmin-web
 nrpe_procs_warn: 500
 nrpe_procs_crit: 600
 # By default run 45 wsgi procs
-mirrorlist_procs: 45
+mirrorlist_procs: 60
 
 # Set this to get the vpn postfix setup
 postfix_group: vpn

roles/mirrormanager/mirrorlist2/tasks/main.yml

@@ -73,3 +73,12 @@
 #  tags:
 #  - mirrorlist2
 #  - selinux
+
+
+- name: HOTFIX - increase the number of possible child processes
+  copy: src="{{ files }}/hotfix/mirrorlist/mirrorlist_server.py" dest=/usr/share/mirrormanager2/mirrorlist_server.py
+        owner=root group=root mode=0755
+  tags:
+  - hotfix
+  notify:
+  - restart mirrorlist-server