Try out this conditional restart stuff.

roles/base/files/common-scripts/conditional-restart.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+# Restart SERVICE only if PACKAGE is installed.
+# We use this throughout handlers/restart_services.yml
+
+SERVICE=$1
+PACKAGE=$2
+
+/usr/bin/rpm -q $PACKAGE
+
+INSTALLED=$?
+
+if [ $INSTALLED -eq 0 ]; then
+    echo "Package $PACKAGE installed.  Attempting restart of $SERVICE."
+    /sbin/service $SERVICE restart
+    exit $?  # Exit with the /sbin/service status code
+fi
+
+# If the package wasn't installed, then pretend everything is fine.
+echo "Package $PACKAGE not installed.  Skipping restart of $SERVICE."
+exit 0