From 9c68191ce848066acc23db8b801525ab950991ce Mon Sep 17 00:00:00 2001
From: Clark Boylan <clark.boylan@gmail.com>
Date: Thu, 10 Sep 2020 11:41:08 -0700
Subject: [PATCH] Improve logging and cache config for zuul web proxy

We attempt to cache things served by zuul-web in our apache proxy. This
is to reduce the load on the zuul-web process which has to query
gearman, the sql database, and eventuall the zookeeper database to
produce its responses.

Things are currently operating slowly and it isn't clear if we're
caching properly. To check that better update our logging format to
record cache hits and misses. Also drop an unnecessary .* in the
CacheEnable url-strings for /static/ as it is unclear if the .* is
treated as a regex here.

Change-Id: Ib57c085fa15365b89b3276e037339dbeddb094e3
---
 .../roles/zuul-web/templates/openstack.vhost.j2      | 12 ++++++++----
 playbooks/roles/zuul-web/templates/zuul.vhost.j2     | 12 ++++++++----
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/playbooks/roles/zuul-web/templates/openstack.vhost.j2 b/playbooks/roles/zuul-web/templates/openstack.vhost.j2
index 328d1a38cb..0e99a5aacf 100644
--- a/playbooks/roles/zuul-web/templates/openstack.vhost.j2
+++ b/playbooks/roles/zuul-web/templates/openstack.vhost.j2
@@ -1,3 +1,7 @@
+{% raw %}
+LogFormat "%h %l %u [%{%F %T}t.%{msec_frac}t] \"%r\" %>s %b %{cache-status}e \"%{Referer}i\" \"%{User-agent}i\"" combined-cache
+{% endraw %}
+
 <VirtualHost *:80>
   ServerName zuul.openstack.org
   ServerAdmin webmaster@openstack.org
@@ -6,7 +10,7 @@
 
   LogLevel warn
 
-  CustomLog ${APACHE_LOG_DIR}/zuul-access.log combined
+  CustomLog ${APACHE_LOG_DIR}/zuul-access.log combined-cache
 
   Redirect / https://zuul.openstack.org/
 
@@ -23,7 +27,7 @@
 
   LogLevel warn
 
-  CustomLog ${APACHE_LOG_DIR}/zuul-ssl-access.log combined
+  CustomLog ${APACHE_LOG_DIR}/zuul-ssl-access.log combined-cache
 
   SSLEngine on
   SSLProtocol All -SSLv2 -SSLv3
@@ -55,7 +59,7 @@
     <IfModule mod_mem_cache.c>
       # TODO: Should we cache the rest of the API too?
       CacheEnable mem /api/status
-      CacheEnable mem /static/.*
+      CacheEnable mem /static/
       # 80MB max cache size. 10 objects at 8MB max each.
       MCacheSize 81920
       MCacheMaxObjectCount 10
@@ -66,7 +70,7 @@
     </IfModule>
     <IfModule mod_cache_disk.c>
       CacheEnable disk /api/status
-      CacheEnable disk /static/.*
+      CacheEnable disk /static/
       CacheRoot /var/cache/apache2/mod_cache_disk
       CacheMaxFileSize 10000000
     </IfModule>
diff --git a/playbooks/roles/zuul-web/templates/zuul.vhost.j2 b/playbooks/roles/zuul-web/templates/zuul.vhost.j2
index a633022127..c46066346d 100644
--- a/playbooks/roles/zuul-web/templates/zuul.vhost.j2
+++ b/playbooks/roles/zuul-web/templates/zuul.vhost.j2
@@ -1,3 +1,7 @@
+{% raw %}
+LogFormat "%h %l %u [%{%F %T}t.%{msec_frac}t] \"%r\" %>s %b %{cache-status}e \"%{Referer}i\" \"%{User-agent}i\"" combined-cache
+{% endraw %}
+
 <VirtualHost *:80>
   ServerName zuul.opendev.org
   ServerAdmin webmaster@openstack.org
@@ -6,7 +10,7 @@
 
   LogLevel warn
 
-  CustomLog ${APACHE_LOG_DIR}/zuul-access.log combined
+  CustomLog ${APACHE_LOG_DIR}/zuul-access.log combined-cache
 
   Redirect / https://zuul.opendev.org/
 
@@ -23,7 +27,7 @@
 
   LogLevel warn
 
-  CustomLog ${APACHE_LOG_DIR}/zuul-ssl-access.log combined
+  CustomLog ${APACHE_LOG_DIR}/zuul-ssl-access.log combined-cache
 
   SSLEngine on
   SSLProtocol All -SSLv2 -SSLv3
@@ -53,7 +57,7 @@
     <IfModule mod_mem_cache.c>
       # TODO: Should we cache the rest of the API too?
       CacheEnable mem /api/tenant/.*/status
-      CacheEnable mem /static/.*
+      CacheEnable mem /static/
       # 80MB max cache size. 10 objects at 8MB max each.
       MCacheSize 81920
       MCacheMaxObjectCount 10
@@ -64,7 +68,7 @@
     </IfModule>
     <IfModule mod_cache_disk.c>
       CacheEnable disk /api/tenant/.*/status
-      CacheEnable disk /static/.*
+      CacheEnable disk /static/
       CacheRoot /var/cache/apache2/mod_cache_disk
       CacheMaxFileSize 10000000
     </IfModule>