Strange log message

[elesouef]

I get the following message (and others similar) in logs of my zabbix server :

5584:20091028:103531 Expression [{27200}>0.75*{27199}] for item [70252][Cisco 4507r - Coeur I:Port 180 Speed] cannot be evaluated: unable to get function value: lastvalue IS NULL for function [27200][Cisco 4507r - Coeur I:Port 180 out bps.min(#2)]

How should I understand it ?

Thanks.

[MrKen]

Hi elesouef,

I can't say for sure, but, does your trigger expression use the delta function?

I'm guessing that you have an expression similar to "ifInOctets.delta(0)}"

If so, try changing (0) to (1). Test it on couple of Ports first.

I would appreciate it very much if you could report back on the result.

HTH

MrKen

[elesouef]

The only triggers that are related to this are :

{Cisco 4507r - Coeur I:Port 180 in bps.min(#2)}>0.75*{Cisco 4507r - Coeur I:Port 180 Speed.max(#2)}

and

{Cisco 4507r - Coeur I:Port 180 out bps.min(#2)}>0.75*{Cisco 4507r - Coeur I:Port 180 Speed.max(#2)}

But the main problem, in my opinion is that :

OID [IF-MIB::ifHCInOctets.180] value has unknown type [0x81] (for example).

This leads to an item which is "not supported".

I just saw that this concerns only unrouted vlans on this Cisco device.

[zabbix_zen]

"lastvalue IS NULL for function"

I've a couple of zabbix_sender metrics that get this via DB queries, (though controlled by me to prevent wrong values).

Check if in that particular moment, the function you're using is able to compute, it may be indeed a NULL value due to the unavailability of data in that moment

[MrKen]

Hi elesouef,

Sorry, seems that I was mistaken.

Can you try snmpget, not snmpwalk.
snmpget -v? -c ? <ip_address> IF-MIB::ifHCInOctets.180

Regarding NULL value, I think NULL is probably the default value in the db, and might work if NULL is changed to zero. However, nothing will work if you can't 'snmpget IF-MIB::ifHCInOctets.180'.

MrKen

[elesouef]

In fact :

$ snmpget -v2c -c xxx <ipaddress> IF-MIB::ifHCInOctets.180
IF-MIB::ifHCInOctets.180 = No Such Instance currently exists at this OID

This seems to be explained like that :

This iface (180), is an unrouted vlan. It exists in vlan db but is not routed. Therefore, the snmp server from the router doesn't "publish" it in snmp server.

I think, as this information is not relevant, I should disable these items.

Any advice ?

[MrKen]

Hi,

The failure of snmpget explains the original errors messages.

Should you disable them? Probably.

Have a look at this http://74.115.12.18/forums/p/19411/79779.aspx

MrKen

[zabbix_zen]

The failure of snmpget explains the original errors messages.

My point exactly, a
"lastvalue IS NULL for function"
tells us Zabbix Server tried to grab a value it was expecting, but the function responsible to compute it failed to return the value.