Load Balancer Hybrid Identification Rules

[SRSkaggs]

I have a situation where F5 load balancers are being discovered just fine, but there are multiple F5 load balancers with the same name and serial number. But there isn't any de-duplication tasks or messages indicating they are duplicates. I noticed it has a hybrid identification rule at the parent load balancer class. I am not sure if that is what is causing it, but I am wondering if there is something I am missing here.

[AJ-TechTrek]

Hi @SRSkaggs ,

As per my understanding How Duplicate CI metric uses hybrid rules in health results.

When CMDB Health calculates duplicates:

• It leverages the effective identification rules in the IRE (including hybrid ones).

• If the rule can’t uniquely identify a CI (even after checking both attributes and relationships), IRE considers there might be duplicate candidates.

• These get logged into the Duplicate CI metric result:

  • Table: cmdb_health_duplicate

  • And shown in CMDB Health dashboard.

So:

 If your hybrid rule is too loose (e.g., only uses relationship to parent which itself isn’t unique), you’ll see more duplicates detected.

 If your hybrid rule is strong (attributes + strong parent), fewer duplicates.

Hybrid rules affect:

• What IRE considers as the unique key for a CI.

• The stricter/more precise your hybrid rules → fewer duplicates.

• The looser/more ambiguous → more duplicates.

Please appreciate the efforts of community contributors by marking appropriate response as Mark my Answer Helpful or Accept Solution this may help other community users to follow correct solution in future.
 

Thank You
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[danielherre]

Hi, just wondering around if this could be the issue: this CI duplication can be related to the fact that the F5 tmsh command used in F5 Load Balancer SSH, Identification section  F5 LB SSH TMSH Step 4 Get hostname, can return more that one line including "hostname", for instance describing remote hosts:

user@(hostname...(tmos)# list sys global-settings
sys global-settings {
	gui-setup disabled
	hostname hostname.localdomain
	remote-host {
		hostl {
			addr AA.BB.CC.DD
			hostname remote.whatever.es

Then on the discovery looks like it will populate 2 entries:
setAttribute(formattedSysName,[hostname, remote])

A workaround could be to refine the command to: "list sys global-settings hostname".

Hope it helps. I take the opportunity to thank the community 🙂
Regards,

[SRSkaggs · Accepted solution]

Found an article and confirmed with ServiceNow this is expected behavior

CMDB Health - Duplicate Metric algorithm - Support and Troubleshooting