Instance Discovery Filter Script [SOLVED]

[victor]

Check that you really get the value with SNMPGetValue - it will return null if SNMP query fails for some reason, and null != 0, so instance that cannot be read will be accepted.

Best regards,
Victor

[Nikk]

Victor you are right, i'm receiving null values, so is there a chance to get rid of them too? I tried to add != null, but no success.

[victor]

Hi,

!= null should work. Can you show full script please?

Best regards,
Victor

[Nikk]

Script looks like this:

snmp = CreateSNMPTransport($node);
value = SNMPGetValue(snmp, ".1.3.6.1.2.1.16.1.1.1.3." . $1);
if (value != null || value != 0) return value;
else return false;

Maybe i just don't get it

[sperlm]

Hello, just a question...

IF value is 0, doesnt it automatically mean that return value is equivalent to return false ?
(thus not passing the filter script)

MS

[victor]

Hi!

Condition (value != null || value != 0) is always true - if value is null then it will not be 0, and vise versa. Correct condition will be (value != null && value != 0), so full script could look like this:

snmp = CreateSNMPTransport($node);
value = SNMPGetValue(snmp, ".1.3.6.1.2.1.16.1.1.1.3." . $1);
return (value != null) && (value != 0);

@sperlm:

you are right, returning 0 is the same as returning false.

Best regards,
Victor

[Nikk]

Thanks for correcting me!

I tried your given script, but still getting 0 values.

I guess i'm doing something wrong, or i haven't given all the necessary information.

[sperlm]

The filter discussed above is for the instanced DCIs, right ?
At the time of applying of the DCI it checks if there are values (non-zero and non-null) and creates real DCI for that one OID.

Where exactly are you getting those 0 values ?

If there are semi-stable values in the OIDs and DCIs are created at that time, these will exist even if OID return 0 afterwards... Check history of the DCIs which are showing 0 now.

You can also check snmpwalk if the 0 value is correct or not.

[Nikk]

Yes, for instanced dcis.

I have checked history and snmpwalk, these values have never been more than 0, see attachment.

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[sperlm]

When you remove those DCIs with zero values manually, they pop back up ?
If not, it must have been something while creating the DCI (mind that whenever you open or modify the DCI it reapplies).
If these return after modyfying/opening the root DCI, there is something in it.