From a0464a329f7959e7283a024124bc1f7f126034d3 Mon Sep 17 00:00:00 2001
From: Keith Whyte <keith@rhizomatica.org>
Date: Tue, 28 Mar 2023 08:40:38 +0200
Subject: [PATCH] improve check for empty rrd

---
 modules/rhizo_base/files/collectd-hack | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/modules/rhizo_base/files/collectd-hack b/modules/rhizo_base/files/collectd-hack
index 22a490d..e76e396 100644
--- a/modules/rhizo_base/files/collectd-hack
+++ b/modules/rhizo_base/files/collectd-hack
@@ -13,8 +13,15 @@ is_empty () {
     exit
   fi
   if  [ "$_o" == "" -o "$_o" == "0.0000000000e+00" -o "$_o" == "NaN" ] ;then
-    debug $1 "$2 is empty"
-    return 1
+    _o=`rrdtool xport DEF:A=/var/lib/collectd/rrd/$(hostname -f)/$2:value:LAST XPORT:A -s -1min -m10 | xmllint --xpath 'string(xport/data/row[v>0]/v)' -`
+    if [ $? != 0 ] ; then
+     echo "Error. exiting."
+     exit
+    fi
+    if  [ "$_o" == "" -o "$_o" == "0.0000000000e+00" -o "$_o" == "NaN" ] ;then
+      debug $1 "$2 is empty"
+      return 1
+    fi
   fi
   if [ "$1" == "ne" ] ; then
     echo "$2 has data"