From dbc66d054bfe2acbf8eb3bee57b05ef3fed9f734 Mon Sep 17 00:00:00 2001
From: Ronnie Sahlberg <sahlberg@ronnie>
Date: Tue, 10 Jul 2007 09:45:14 +1000
Subject: dont restart the tcp service after a ip takeover,   it is more
 efficient to just kill off the tcp connections

(This used to be ctdb commit bc481c3f1a44c50648488c4f8a7f15ec395d446f)
---
 ctdb/config/events.d/60.nfs | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/ctdb/config/events.d/60.nfs b/ctdb/config/events.d/60.nfs
index 48b50f126b..47f8a903a6 100755
--- a/ctdb/config/events.d/60.nfs
+++ b/ctdb/config/events.d/60.nfs
@@ -61,12 +61,18 @@ case $cmd in
 	;;
 
      recovered)
-        # restart NFS to ensure that all TCP connections to the released ip
-	# are closed
+        # RST all tcp connections used for NFS to ensure that they do
+	# not survive in ESTABLISHED state across a failover/failback
+	# and create an ack storm
 	[ -f /etc/ctdb/state/nfs/restart ] && {
-		( service nfs status > /dev/null 2>&1 && 
-                      service nfs restart > /dev/null 2>&1 &&
-		      service nfslock restart > /dev/null 2>&1 ) &
+		netstat -tn |egrep '^tcp.*\s+[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+:2049\s+.*ESTABLISHED' | awk '{print $4" "$5}' | while read dest src; do
+			srcip=`echo $src | cut -d: -f1`
+			srcport=`echo $src | cut -d: -f2`
+			destip=`echo $dest | cut -d: -f1`
+			destport=`echo $dest | cut -d: -f2`
+			ctdb killtcp $srcip:$srcport $destip:$destport
+			ctdb killtcp $destip:$destport $srcip:$srcport 
+		done
 	} > /dev/null 2>&1
 	/bin/rm -f /etc/ctdb/state/nfs/restart
 
-- 
cgit