From c3b0b9034e6b35187a125283e55056ae90cbbc4a Mon Sep 17 00:00:00 2001
From: Dan Smith <dansmith@redhat.com>
Date: Fri, 4 Aug 2023 06:41:30 -0700
Subject: [PATCH] Disable waiting forever for connpool workers

This will cause apache to no longer wait forever for a connection
pool member to become available before returning 503 to the client.
This may help us determine if some of the timeouts we see when
talking to the services come from an overloaded apache.

Change-Id: Ibc19fc9a53e2330f9aca45f5a10a59c576cb22e6
---
 lib/apache | 6 +++---
 lib/tls    | 4 +++-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/lib/apache b/lib/apache
index 76eae9c057..cf7215bef2 100644
--- a/lib/apache
+++ b/lib/apache
@@ -290,7 +290,7 @@ function write_uwsgi_config {
         apache_conf=$(apache_site_config_for $name)
         iniset "$file" uwsgi socket "$socket"
         iniset "$file" uwsgi chmod-socket 666
-        echo "ProxyPass \"${url}\" \"unix:${socket}|uwsgi://uwsgi-uds-${name}\" retry=0 " | sudo tee -a $apache_conf
+        echo "ProxyPass \"${url}\" \"unix:${socket}|uwsgi://uwsgi-uds-${name}\" retry=0 acquire=1 " | sudo tee -a $apache_conf
         enable_apache_site $name
         restart_apache_server
     fi
@@ -351,7 +351,7 @@ function write_local_uwsgi_http_config {
     apache_conf=$(apache_site_config_for $name)
     echo "KeepAlive Off" | sudo tee $apache_conf
     echo "SetEnv proxy-sendchunked 1" | sudo tee -a $apache_conf
-    echo "ProxyPass \"${url}\" \"http://$APACHE_LOCAL_HOST:$port\" retry=0 " | sudo tee -a $apache_conf
+    echo "ProxyPass \"${url}\" \"http://$APACHE_LOCAL_HOST:$port\" retry=0 acquire=1 " | sudo tee -a $apache_conf
     enable_apache_site $name
     restart_apache_server
 }
@@ -370,7 +370,7 @@ function write_local_proxy_http_config {
 
     echo "KeepAlive Off" | sudo tee $apache_conf
     echo "SetEnv proxy-sendchunked 1" | sudo tee -a $apache_conf
-    echo "ProxyPass \"${loc}\" \"$url\" retry=0 " | sudo tee -a $apache_conf
+    echo "ProxyPass \"${loc}\" \"$url\" retry=0 acquire=1 " | sudo tee -a $apache_conf
     enable_apache_site $name
     restart_apache_server
 }
diff --git a/lib/tls b/lib/tls
index a1e162d2e2..48e5929a2b 100644
--- a/lib/tls
+++ b/lib/tls
@@ -541,9 +541,11 @@ $listen_string
 
     # Avoid races (at the cost of performance) to re-use a pooled connection
     # where the connection is closed (bug 1807518).
+    # Set acquire=1 to disable waiting for connection pool members so that
+    # we can determine when apache is overloaded (returns 503).
     SetEnv proxy-initial-not-pooled
     <Location />
-        ProxyPass http://$b_host:$b_port/ retry=0 nocanon
+        ProxyPass http://$b_host:$b_port/ retry=0 nocanon acquire=1
         ProxyPassReverse http://$b_host:$b_port/
     </Location>
     ErrorLog $APACHE_LOG_DIR/tls-proxy_error.log