Instance Discovery Filter Script [SOLVED]

Victor Kirhenshtein

@sperlm said in Instance Discovery Filter Script [SOLVED]:

Thanks for the reply, filters work exactly as I need now.

Few clarifications:

a)
In my previous question 4) I was referring to the wiki information under Templates section "Macros in template items"

You can use various macros in name, description, and instance fields of template DCI.

namely: script:name - String returned by script name. Script should be stored in script library (accessible via Configuration -> Script Library). Inside the script, you can access current node's properties via $node variable.

To put the question short - where exactly it can be used?
(as the wiki information does not make sense to me - DCI form has no "name", macro {instance} can be used in the Parameter on the other hand)

Macros in templates expands when template being applied to node. It is useful when you want to put some node-specific information during template apply (node IP address for example) into parameter name or description. "name" was the old universal name for what you now see as "Parameter" for agent DCI, "OID" for SNMP DCI, etc. It is still used in some places.

@sperlm said in Instance Discovery Filter Script [SOLVED]:

b)
Performance tab - a little insight on this would be appreciated.
(did not find any on wiki or forums and this looks like it can solve my problem with viewing the collected data, namely the automated ones)

Performance tab shows line charts with last hour data for all DCIs marked to be shown on performance tab. You can enable DCI for performance tab in DCI properties, on "Performance Tab" page.

@sperlm said in Instance Discovery Filter Script [SOLVED]:

b)
If dci and node parameters are global, does it mean we can use class reference attributes like $node->snmpOID anywhere?
I am already filtering nodes for templates with this functionality so I assume it is possible.

Yes, all scripts related to nodes have $node variable set, and all scripts related to DCIs have $dci variable set.

@sperlm said in Instance Discovery Filter Script [SOLVED]:

c)
I also tried to use the same script functions from instance discovery in automatic apply rules for templates but could get results only with direct scripts, when I try to do the same thing with use/script it does nothing (or I was not able to test it properly).

There are no difference between automatic apply rule script an any other script regarding library use. Most likely you've make some mistake. Please post your scripts here.

Best regards,
Victor

sperlm

Thanks for the patience, youre really doing a great job.
(btw I found where the Performance Tab is just now, thats why I was confused and asked... sorry :-[)

As for the filtering scripts I tried to convert this:

if (($node->snmpOID) == ".1.3.6.1.4.1.25506.1.1")
{
	snmp = CreateSNMPTransport($node);
	x = SNMPGetValue(snmp, ".1.3.6.1.4.1.25506.2.6.1.1.1.1.6.47");
	if (x != null) return (x > 0);
	else return 0;
}

Filter is to pick nodes that have set snmpOID and CPU statistics at address 47.
Structure is built with this ideas:

if snmpOID is not equal the whole CreateSNMPTransport is not executed (and savig a little bit of system resources)
asking for SNMPGetValue just once to do two tests
return 1 only if value is numerical and non-zero (if I tried to return just (x>0) there is possibility x is null and creating error)

Tried to "convert" it to script style this way:

use filterTools;
if (($node->snmpOID) == ".1.3.6.1.4.1.25506.1.1")
{
	x = 0;
	x = aboveZero(.1.3.6.1.4.1.25506.2.6.1.1.1.1.6.47);
	return x;
}

filterTools:

sub aboveZero(dci)
{
	snmp = CreateSNMPTransport($node);
	x = SNMPGetValue(snmp, dci);
	if (x != null) return (x > 0);
	else return 0;
}

With Regards

Milan Sperl

Victor Kirhenshtein

You forgot double quotes around OID passed to aboveZero function, so script ends up with syntax error. And you can shorten the script to just

return ($node->snmpOID == ".1.3.6.1.4.1.25506.1.1") && aboveZero(".1.3.6.1.4.1.25506.2.6.1.1.1.1.6.47");

function aboveZero will be called only if first condition is true, because NXSL uses short-circuit expression evaluation (http://en.wikipedia.org/wiki/Short-circuit_evaluation).

Best regards,
Victor

sperlm

My bad. It works now, thanks again.

The short-circuit functionality si great too.
Can shorten structures like this:

if (x != null) return (x > 0);
else return 0;

... into this:

if (x != null && x > 0) return 1;

-if I don't need to catch return 0, which is not needed in filters
-in scripts I should add "else return 0;"

p.s. I unintentionally left my test structure (that "x = 0" etc, using 3 lines with just "X") in the last post, sorry about that. It was there only because I was testing it and commenting out lines or skipping the filter altogether.

With Regards

Milan Sperl

Nikk

Hi,

I tried your script, for getting only non-zero values:

@victor said in Instance Discovery Filter Script [SOLVED]:

Then, on instance discovery page, I set discovery method to "SNMP Walk - OIDs", set base OID to .1.3.6.1.2.1.2.2.1.16, and use the following filtering script:

snmp = CreateSNMPTransport($node);
return SNMPGetValue(snmp, ".1.3.6.1.2.1.2.2.1.16." . $1) != 0;

but it is not working, I still get 0 values. Maybe that is because i have delta calculation?

My parameter is: .1.3.6.1.2.1.31.1.1.1.10.{instance}
and in Instance tab:
SNMP Walk - OID's
.1.3.6.1.2.1.31.1.1.1.10

and script:
snmp = CreateSNMPTransport($node);
return SNMPGetValue(snmp, ".1.3.6.1.2.1.31.1.1.1.10." . $1) != 0;

Thanks in advance,
Nikk

Victor Kirhenshtein

This filtering script checks that absolute value for given OID is 0. If you have non-zero value which is not changing over time, OID will pass filter but you will still get 0 as delta value. If you want to filter out any non-changing values, you should get two samples and check delta, like this:

snmp = CreateSNMPTransport($node);
v1 = SNMPGetValue(snmp, ".1.3.6.1.2.1.2.2.1.16." . $1);
sleep(10000);  // sleep for 10 seconds
v2 = SNMPGetValue(snmp, ".1.3.6.1.2.1.2.2.1.16." . $1);
return (v2 - v1) != 0;

Of course, practical use of such method is questionable and depends on your goals - you will either miss slowly changing OIDs if sleep interval is too small or make configuration polling extremely long if you have lot of instances and long sleep interval.

Best regards,
Victor

Nikk

Hi,

Yea, I thought that it could be something with non-zero values, but some of them actually are 0 values, as some ports, have never been opened.
I'm monitoring many parameters on a lot of instances, so maybe I just delete the unnecessary instances for now
Thank you for idea any way

Nikk

Percy

hi,
I tried your script from that i am able to get non zero interfaces but still there is a problem why it is giving 0 value of traffic on interfaces.
regards
Percy

sperlm

Hello, I will reply here so others can try to help too.

DESCRIPTION -interface traffic: {instance}
PARAMETER -1.3.6.1.2.1.2.2.1.16.{instance}
base OID to .1.3.6.1.2.1.2.2.1.16
snmp = CreateSNMPTransport($node);
return SNMPGetValue(snmp, ".1.3.6.1.2.1.2.2.1.16." . $1) != 0;

Not sure if it is the problem you encountered but I had problems with this structure because there is no guarantee there will be 0 value, there can be null too so I wrote it like this:

snmp = CreateSNMPTransport($node);
x = SNMPGetValue(snmp, ".1.3.6.1.2.1.2.2.1.16." . $1);
if (x != null) return (x > 0);
else return 0;

p.s. does it mean you get the desired DCI with correct OID on all of your nodes but the value there is 0 or it creates unwanted DCIs with wrong OID?

Percy

hi Sperlm,

thank you for replying back.
[/quote]Not sure if it is the problem you encountered but I had problems with this structure because there is no guarantee there will be 0 value, there can be null too so I wrote it like this:

snmp = CreateSNMPTransport($node);
x = SNMPGetValue(snmp, ".1.3.6.1.2.1.2.2.1.16." . $1);
if (x != null) return (x > 0);
else return 0;[/quote]

i tried this Script on the instance discovery tab of Template than applied to Node i get the DCI for Non Zero values interfaces [ like 1,2,9,10,33] pls check on attachment but when i see the collected values for these DCI it shows 0 value...

[/quote]p.s. does it mean you get the desired DCI with correct OID on all of your nodes but the value there is 0 or it creates unwanted DCIs with wrong OID?
[/quote]

yes getting 0 value. why it does not give the values of traffic on interfaces.
Regards,
Percy

Percy

@sperlm said in Instance Discovery Filter Script [SOLVED]:

Hello, I will reply here so others can try to help too.

DESCRIPTION -interface traffic: {instance}
PARAMETER -1.3.6.1.2.1.2.2.1.16.{instance}
base OID to .1.3.6.1.2.1.2.2.1.16
snmp = CreateSNMPTransport($node);
return SNMPGetValue(snmp, ".1.3.6.1.2.1.2.2.1.16." . $1) != 0;

Not sure if it is the problem you encountered but I had problems with this structure because there is no guarantee there will be 0 value, there can be null too so I wrote it like this:

snmp = CreateSNMPTransport($node);
x = SNMPGetValue(snmp, ".1.3.6.1.2.1.2.2.1.16." . $1);
if (x != null) return (x > 0);
else return 0;

p.s. does it mean you get the desired DCI with correct OID on all of your nodes but the value there is 0 or it creates unwanted DCIs with wrong OID?

@percy said in Instance Discovery Filter Script [SOLVED]:

hi Sperlm,

thank you for replying back.

Not sure if it is the problem you encountered but I had problems with this structure because there is no guarantee there will be 0 value, there can be null too so I wrote it like this:

snmp = CreateSNMPTransport($node);
x = SNMPGetValue(snmp, ".1.3.6.1.2.1.2.2.1.16." . $1);
if (x != null) return (x > 0);
else return 0;
[/quote]
i tried this Script on the instance discovery tab of Template than applied to Node i get the DCI for Non Zero values interfaces [ like 1,2,9,10,33] pls check on attachment but when i see the collected values for these DCI it shows 0 value...

[/quote]

p.s. does it mean you get the desired DCI with correct OID on all of your nodes but the value there is 0 or it creates unwanted DCIs with wrong OID?
[/quote]
yes getting 0 value. why it does not give the values of traffic on interfaces.
[/quote]

sperlm

Hi,

do a snmpwalk on the device with .1.3.6.1.2.1.2.2.1.16 value.
It should list all subsequent oids (.1.3.6.1.2.1.2.2.1.16.0, .1.3.6.1.2.1.2.2.1.16.1 etc..) with values and see if there are values in 1, 2, 9, 10, 33.

One more thing - Instance discovery method should be SNMP Walk - OIDs (but I suppose you've got that right).

With regards,
Milan

Percy

hi,

yes i checked there are values . i have attached the screen shot.

thanks,
Percy

sperlm

Can you post screenshots with the Last values (for the node) view and History (for one DCI) too ?

Percy

hi Milan,

thanks for the patience posting you the screenshots for the History of the DCI for the interface 1 and last value.
In Delta calculation tab :- Average Delta Per minute, it is correct or will be something else ?

regards.
Percy

Percy

hi Sperlm..

its working now. thanks a lot for the Support.
posting the Screenshots for the last values.

with Regards
Percy

sperlm

What was the problem if I may ask ?

I was also wandering what you mean by the Delta calculation tab, because only delta calculation I am aware of is in the Transformation tab...

Percy

hi..,

i didn't change anything in delta calculation but a little change in this Script.

snmp = CreateSNMPTransport($node);
x = SNMPGetValue(snmp, ".1.3.6.1.2.1.2.2.1.16." . $1);
if (x != null) return x; // you gave me like this return (x > 0 );
else return 0;

i am also confused how it started collecting data. due to that change in the script or happened automatically. but still there is 0 value for the other interfaces (10,2.33) strange why it gives for 1,9 did you notice this in screenshots.

thank you,
Percy

Nikk

@victor said in Instance Discovery Filter Script [SOLVED]:

Hi!

You actually thinking in right direction - you can use SNMPGet function to read value of each instance and determine to include it or not. Below is a working example of such approach. I use OID .1.3.6.1.2.1.2.2.1.16 (ifOutOctets) as a base. I use

Port traffic: {instance}

as description and

.1.3.6.1.2.1.2.2.1.16.{instance}

as parameter name. Correct parameter name is important, because {instance} will be the part after base OID you configure on instance discovery page, not the full OID.

Then, on instance discovery page, I set discovery method to "SNMP Walk - OIDs", set base OID to .1.3.6.1.2.1.2.2.1.16, and use the following filtering script:

snmp = CreateSNMPTransport($node);
return SNMPGetValue(snmp, ".1.3.6.1.2.1.2.2.1.16." . $1) != 0;

Now just close data collection configuration for the node and run configuration poll. You should get DCIs for all OIDs with non-zero value.

Best regards,
Victor

@victor said in Instance Discovery Filter Script [SOLVED]:

This filtering script checks that absolute value for given OID is 0. If you have non-zero value which is not changing over time, OID will pass filter but you will still get 0 as delta value.

So I changed from delta value to original value and i'm still getting 0 values. Absolute values all are 0s (checked with snmpwalk).
Where is the problem?
Configuration is the same, except oid is now .1.3.6.1.2.1.31.1.1.1.3. (CRCAlignErrors) where all values are 0:

@nikk said in Instance Discovery Filter Script [SOLVED]:

My parameter is: .1.3.6.1.2.1.31.1.1.1.10.{instance}
and in Instance tab:
SNMP Walk - OID's
.1.3.6.1.2.1.31.1.1.1.10

and script:
snmp = CreateSNMPTransport($node);
return SNMPGetValue(snmp, ".1.3.6.1.2.1.31.1.1.1.10." . $1) != 0;

Victor Kirhenshtein

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

NetXMS Forum

Instance Discovery Filter Script [SOLVED]