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I am attempting to extend snmp to return number of a given process

This is the tool, saved at /usr/bin/count_proc.sh

#!/bin/bash
ps aux | awk '
BEGIN { c=0 }
/processname$/ { c=c+1 }
END { print $c }'

in my snmpd.conf, I have the following line:

extend .1.3.6.1.4.1.8072.9999.1 count_proc /usr/bin/count_proc.sh

However, I am not able to retrieve the result of this command with this OID. When I run a snmp query for this OID, the result is:

Value: (Snmp No Such object)

If I run traverse the snmp tree, I finally see something, but its strange... "Next OID" is the name of my tool, and not numeric at all.

OID: .1.3.6.1.4.1.8072.9999.1.2.1.2.9.99.111.117.110.116.95.102.119.100
Next OID: /usr/bin/count_proc.sh
Value: 1

And finally, I will see the value I am expecting.

OID: .1.3.6.1.4.1.8072.9999.1.3.1.1.9.99.111.117.110.116.95.102.119.100
Value: 13

But this is not the OID I expected to query to find the output. I will also find the output on several other OIDs.

Is this working as intended, or am I missing something important here?

Dog eat cat world
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2 Answers2

4

Personally I use extend without OID, like:

extend count_proc /usr/bin/count_proc.sh

The OID generated by snmp is simple, the result is:
NET-SNMP-EXTEND-MIB::nsExtendOutput1Line.”count_proc”

The OID is :
1.3.6.1.4.1.8072.1.3.2.3.1.1.10.99.111.117.110.116.95.112.114.111.99

Explanation : 10 : number of character in "count_proc" 99 : ASCII decimal value of 'c' 111 : ASCII decimal value of 'o' 117 : ASCII decimal value of 'u' 110 : ASCII decimal value of 'n' 116 : ASCII decimal value of 't' 95 : ASCII decimal value of '_' 112 : ASCII decimal value of 'p' 114 : ASCII decimal value of 'r' 111 : ASCII decimal value of 'o' 99 : ASCII decimal value of 'c'

So you can easily retrieve the OID programatically.

Esa Jokinen
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Damien_FR
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-1

Probably This link can help you in "extend" naming convention

reiven
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  • Thanks, but if I understand the NET-SNMP-EXTEND-MIB correctly, the OID given will dynamically assigned, and I have to programatically find it. This scenario seems to be covered in http://serverfault.com/questions/374064/will-the-oid-for-a-custom-extend-snmp-call-be-the-same-on-multiple-boxes?rq=1 – Dog eat cat world Jun 11 '14 at 16:09