From b230858fb494fc4773dcfa3ffa1bcf59d4171c92 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9o=20Gillot-Lamure?=
 <leo.gillot-lamure-ext@socgen.com>
Date: Tue, 23 May 2023 23:27:52 +0200
Subject: [PATCH] loadbalancer: remove support for haproxy_processes
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Threads are the recommended way to scale CPU performance since HAProxy
1.8.

Official documentation says: « While "nbproc" historically used to be the only
way to use multiple processors, it also involved a number of shortcomings
related to the lack of synchronization between processes (health-checks, peers,
stick-tables, stats, ...) which do not affect threads. As such, any modern
configuration is strongly encouraged to migrate away from "nbproc" to
"nbthread". ».

Change-Id: I6f2e9d74e68703c8e0827e495945a75f020e1561
---
 ansible/roles/loadbalancer/defaults/main.yml              | 4 +---
 .../loadbalancer/templates/haproxy/haproxy_main.cfg.j2    | 8 +-------
 .../notes/haproxy-drop-processes-f6951f7b995e0694.yaml    | 7 +++++++
 3 files changed, 9 insertions(+), 10 deletions(-)
 create mode 100644 releasenotes/notes/haproxy-drop-processes-f6951f7b995e0694.yaml

diff --git a/ansible/roles/loadbalancer/defaults/main.yml b/ansible/roles/loadbalancer/defaults/main.yml
index 7db023e017..bb38946a74 100644
--- a/ansible/roles/loadbalancer/defaults/main.yml
+++ b/ansible/roles/loadbalancer/defaults/main.yml
@@ -52,9 +52,7 @@ keepalived_traffic_mode: "multicast"
 # Extended global configuration, optimization options.
 haproxy_max_connections: 40000
 haproxy_threads: 1
-# More than 1 process is deprecated by HAProxy, prefer haproxy_threads
-haproxy_processes: 1
-haproxy_process_cpu_map: "no"
+haproxy_thread_cpu_map: "no"
 # Matches the mariadb 10000 max connections limit
 haproxy_defaults_max_connections: 10000
 
diff --git a/ansible/roles/loadbalancer/templates/haproxy/haproxy_main.cfg.j2 b/ansible/roles/loadbalancer/templates/haproxy/haproxy_main.cfg.j2
index 40d571bf93..0e572333b9 100644
--- a/ansible/roles/loadbalancer/templates/haproxy/haproxy_main.cfg.j2
+++ b/ansible/roles/loadbalancer/templates/haproxy/haproxy_main.cfg.j2
@@ -6,14 +6,8 @@ global
     daemon
     log {{ syslog_server }}:{{ syslog_udp_port }} {{ syslog_haproxy_facility }}
     maxconn {{ haproxy_max_connections }}
-    nbproc {{ haproxy_processes }}
     nbthread {{ haproxy_threads }}
-    {% if (haproxy_processes | int > 1) and (haproxy_process_cpu_map | bool) %}
-        {% for cpu_idx in range(0, haproxy_processes) %}
-    cpu-map {{ cpu_idx + 1 }} {{ cpu_idx }}
-        {% endfor %}
-    {% endif %}
-    {% if (haproxy_threads | int > 1) and (haproxy_process_cpu_map | bool) %}
+    {% if (haproxy_threads | int > 1) and (haproxy_thread_cpu_map | bool) %}
     cpu-map auto:1/all 0-63
     {% endif %}
     stats socket /var/lib/kolla/haproxy/haproxy.sock group kolla mode 660{% if haproxy_socket_level_admin | bool %} level admin{% endif %}
diff --git a/releasenotes/notes/haproxy-drop-processes-f6951f7b995e0694.yaml b/releasenotes/notes/haproxy-drop-processes-f6951f7b995e0694.yaml
new file mode 100644
index 0000000000..9b5269dde6
--- /dev/null
+++ b/releasenotes/notes/haproxy-drop-processes-f6951f7b995e0694.yaml
@@ -0,0 +1,7 @@
+---
+upgrade:
+  - |
+    Configuring HAProxy nbproc setting via ``haproxy_processes`` and
+    ``haproxy_process_cpu_map`` variables has been dropped since
+    threads are the recommended way to scale CPU performance since 1.8.
+    Please use ``haproxy_threads`` and ``haproxy_thread_cpu_map`` instead.