Poller[0] Host[xx] ERROR: Empty result

[enriquet]

Hi. I hope somebody can help in this problem.
I have a perl script, very simple one, just do a snmpget and parse the result to get each binary digit.
$mib="x.x.x.x.x.x.x";
$host=$ARGV[0];

open(COMANDO, "/usr/bin/snmpget -v2c -c public $host $mib | ");
$salida = <COMANDO>;
close(COMANDO);


# la siguiente linea extrae el valor despues del igual
if ($salida =~ /.*.INTEGER:(.*)/) {
$lectura=$1;
}

$div=$lectura;

for ($i=0; $i<=13; $i++) {
$valor_di[$i]=$div % 2;
print "di$i:$valor_di[$i] ";
$div=$div / 2;
}

print "\n";

The result of the execution of this script is something like:
di0:1 di1:0 di2:0 di3:0 di4:0 di5:1 di6:1 di7:0 di8:0 di9:1 di10:1 di11:0 di12:0 di13:0

Two strange things are happening:
1) in the log i get the message
02/12/2020 05:30:02 PM - SPINE: Poller[0] Host[57] ERROR: Empty result [172.26.25.230]: '/usr/bin/perl /usr/share/cacti/site/scripts/Di.pl 172.26.25.230'

This happens, not every time poller is run, but very frequently

2) di values are graphed normally, except for di0. This particulary one oscillates between 2 posible values (0 and 1). Should be always 1 and i found no reason for that.
To analize this problem i graphed the rough value obtained with snmp polling and value is graphed ok
The rest of di values also graph ok.

All the values are from the same device and script executed manually with www-data user executes ok:
sudo -u www-data /usr/bin/perl /usr/share/cacti/site/scripts/Di.pl <device ip>
di0:1 di1:0 di2:0 di3:0 di4:0 di5:1 di6:1 di7:0 di8:0 di9:1 di10:1 di11:0 di12:0 di13:0

As shown i am using absolute paths por calling perl from cacti, and inside perl script to execute snmpget. As most of the graphs are working ok, it doesnt seem to be a problem with device, or with script permisions, but i am not sure.

So any help is very welcome of what to see or what to do.

[enriquet]

Just to help anybody i had to use poller.php. Apparently there is a bug with spine or something. Nothing else worked

[TheWitness]

Wrong. Its well documented you have to print everything at once. You were printing in parts which is not supported in spine for performance reasons.

[enriquet]

Didnt know about that. Is it advisable to modify all scripts to do that even with cmd.php for performance reasons?. I am willing to do that without major problems if that is important