CMDB Identification Error: Found duplicate Lookup items (0 and 2) in the payload index 0 using fields serial_number,serial_number_type

sherard
Mega Expert

We're running a discovery to scan for Hitachi Storage Servers G1000s. The CIM probe runs and creates the WBEM Service CI but errors when Identifying the Storage Server CI. We repeatedly see this error in the discovery logs. Any idea what this means?

CMDB Identification Error: Found duplicate Lookup items (0 and 2) in the payload index 0 using fields serial_number,serial_number_type

4 REPLIES 4

Dave Ainsworth
ServiceNow Employee
ServiceNow Employee

Hi Sherard,



There is some information right at the bottom of this page….



Identification engine error messages



What I think that means is that in the payload being sent to the identification engine, there are duplicate records. i.e. there are 2 serial number entries with the same serial number and same serial number type. It therefore can't attempt the identification.



Check the probe results for the identification probe and see if you can see 2 entries with the same serial number and same serial number type.



Regards,



Dave


David,



So, I'm a little confused. I looked up the link you provided and found the error message. But I dont understand the description or resolution info provided.



Description: Found duplicate records in lookup table.


Resolution: Check de-duplication tasks for information about all duplicates, and then delete duplicate records.



What lookup table is it referring to for me to delete the duplicate records? also, I don't see any de-duplication tasks that refer to the IP that is receiving this error.



The discovery payload that is coming back to from the probe does refer to the serial number multiple times. But how do I fix that as this output comes from the scanned discovered source.


Hi Sherard,



I think it is probably this error message:



find_real_file.png



When data comes back in the identification probe results, the sensor then creates a payload to send to the identification engine. The identification engine uses this to attempt to identify the CI in the CMDB. Included in the payload is data for lookup rules. Lookup rules are for tables related to the main CI. A little more information is here:



https://docs.servicenow.com/bundle/istanbul-it-service-management/page/product/configuration-managem...



In short, your hardware identification rule will have a lookup rule for serial number and serial number type on the serial number table. It is a lookup because you are actually attempting to identify a hardware CI (storage server in this case) but the identifier entry is using data in the serial number table. So it is attempting to find serial numbers and serial number types in the serial number table that it can use to identify the main CI. The serial number table has a reference to the hardware CI so once it finds a match, it knows which hardware CI the serial number belongs to and can identify the storage server CI. The specific identifier entry I am referring to will be similar to the following:



find_real_file.png



I can't be sure with not being able to look at the probe results but in your case, what I think will be happening is that there will be duplicate entries in the identification probe results and you will have multiple entries for the same serial number/serial number type combination. So I think this is the first place to check.



If this is the issue, then ideally you would want to find out why duplicate entries are in there but this could be due to a number of reasons - device reporting multiple entries, sensor creating a duplicate. Probably the most likely is that this is data coming from the device itself but again, I can't be sure. This is an example from the identification sensor for a Windows PC:



<result id="b0fc08860a0a0baa005952556d837e18" name="WMI: Hardware Information" order="1" topic="WMIRunner">


<results probe_time="3515" result_code="0">


<result>


<output>


{"related_data":{"srlArr":[{"serial_number_type":"system","serial_number":"ABC123"},{"serial_number_type":"uuid","serial_number":"DEF456"},




If the data coming from the device can't be fixed, then either a new identifier rule could be created for the storage server which does not have the serial number, serial number type identifier entry (i.e. is exactly the same as the Hardware rule without the serial number/serial number type rule) or perhaps the identification sensor could be changed to filter out duplicates.



However you might first want to raise an incident with support to help investigate further where the issue is.



Regards,



Dave


cyked
Mega Guru

Hi Shepard, did you ever get resolution for this?



In both our NPE Jakarta instances on some switches I see this message about 100 times: CMDB Identification Error: Found duplicate Lookup items (1 and 21) in the payload index 0 using fields mac_address.   In the other instances where we haven't upgraded (we're in the middle of testing) discovery works fine on the same switch, and the SNMP - Identity payload looks the same (there's a MAC listed about 70 or so times).