From 5a52d8e4a0c5d4c246deb8851ef893df63ee0847 Mon Sep 17 00:00:00 2001
From: Pierre Riteau <pierre@stackhpc.com>
Date: Wed, 19 Aug 2020 17:56:30 +0200
Subject: [PATCH] Add workaround for keystonemiddleware/neutron memcached issue
There is an issue where keystonemiddleware connections to memcached from
neutron-server grow beyond configured values [1], eventually reaching
the maximum number of connections accepted by memcached servers. Other
services do not appear to be affected by this issue.
A workaround is to use the advanced memcached pool. Despite its
documentation claiming to only work with Python 2, it appears to work
fine on Python 3.
[1] https://bugs.launchpad.net/keystonemiddleware/+bug/1883659
Change-Id: Ifbbc2022839cbc575848d830600241c61603c80b
Closes-Bug: #1892210
---
ansible/roles/neutron/templates/neutron.conf.j2 | 3 +++
...utron-memcached-connection-issue-84f5affa217b4612.yaml | 8 ++++++++
2 files changed, 11 insertions(+)
create mode 100644 releasenotes/notes/fix-neutron-memcached-connection-issue-84f5affa217b4612.yaml
diff --git a/ansible/roles/neutron/templates/neutron.conf.j2 b/ansible/roles/neutron/templates/neutron.conf.j2
index 699465f8c2..115169ac53 100644
--- a/ansible/roles/neutron/templates/neutron.conf.j2
+++ b/ansible/roles/neutron/templates/neutron.conf.j2
@@ -115,6 +115,9 @@ memcache_secret_key = {{ memcache_secret_key }}
memcached_servers = {% for host in groups['memcached'] %}{{ 'api' | kolla_address(host) | put_address_in_context('memcache') }}:{{ memcached_port }}{% if not loop.last %},{% endif %}{% endfor %}
+# Workaround for https://bugs.launchpad.net/keystonemiddleware/+bug/1883659
+memcache_use_advanced_pool = True
+
[oslo_messaging_notifications]
transport_url = {{ notify_transport_url }}
{% if neutron_enabled_notification_topics %}
diff --git a/releasenotes/notes/fix-neutron-memcached-connection-issue-84f5affa217b4612.yaml b/releasenotes/notes/fix-neutron-memcached-connection-issue-84f5affa217b4612.yaml
new file mode 100644
index 0000000000..a7bc30f7f3
--- /dev/null
+++ b/releasenotes/notes/fix-neutron-memcached-connection-issue-84f5affa217b4612.yaml
@@ -0,0 +1,8 @@
+---
+fixes:
+ - |
+ Fixes `LP#1892210
+ <https://bugs.launchpad.net/kolla-ansible/+bug/1892210>`__ where the number
+ of open connections to Memcached from ``neutron-server`` would grow over
+ time until reaching the maximum set by ``memcached_connection_limit`` (5000
+ by default), at which point the Memcached instance would stop working.