From c15ed74f63559dca7692cfcfe695e195c3401454 Mon Sep 17 00:00:00 2001
From: Sheng Yang <sheng.yang@citrix.com>
Date: Tue, 4 Nov 2014 16:26:23 -0800
Subject: [PATCH] CLOUDSTACK-7841: Gracefully reload haproxy config

The old way would disconnect all the existing connections through haproxy when
reload the config.

This new way would ensure that all the existing connections would still alive
after reload the config.
---
 systemvm/patches/debian/config/root/reconfigLB.sh | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/systemvm/patches/debian/config/root/reconfigLB.sh b/systemvm/patches/debian/config/root/reconfigLB.sh
index 70a29126db3..e68cc3df492 100755
--- a/systemvm/patches/debian/config/root/reconfigLB.sh
+++ b/systemvm/patches/debian/config/root/reconfigLB.sh
@@ -23,23 +23,16 @@ new_config=$1
 
 # save previous state
   mv /etc/haproxy/haproxy.cfg /etc/haproxy/haproxy.cfg.old
-  mv /var/run/haproxy.pid /var/run/haproxy.pid.old
 
   mv $new_config /etc/haproxy/haproxy.cfg
-  kill -TTOU $(cat /var/run/haproxy.pid.old)
-  sleep 2
-  if haproxy -D -p /var/run/haproxy.pid -f /etc/haproxy/haproxy.cfg; then
+  if haproxy -p /var/run/haproxy.pid -f /etc/haproxy/haproxy.cfg -sf $(cat /var/run/haproxy.pid); then
     logger -t cloud "New haproxy instance successfully loaded, stopping previous one."
-    kill -KILL $(cat /var/run/haproxy.pid.old)
-    rm -f /var/run/haproxy.pid.old
     ret=0
   else
     logger -t cloud "New instance failed to start, resuming previous one."
-    kill -TTIN $(cat /var/run/haproxy.pid.old)
-    rm -f /var/run/haproxy.pid
-    mv /var/run/haproxy.pid.old /var/run/haproxy.pid
     mv /etc/haproxy/haproxy.cfg $new_config
     mv /etc/haproxy/haproxy.cfg.old /etc/haproxy/haproxy.cfg
+    haproxy -p /var/run/haproxy.pid -f /etc/haproxy/haproxy.cfg -sf $(cat /var/run/haproxy.pid)
     ret=1
   fi