Discovery not updating CIs without changes

[Armacar2]

Hi Experts,

I recently noticed that some CIs doesn't updated by Discovery if the CI hasn't have any change. The fields "Discovery source" and "Most recent discovery" are empty, but CIs was created by Discovery the very first time (Created by = MID Server). The problem is that many of this CIs are been classified as "Stale" CIs because of this reason. I have turn on and off the Discovery property "Use probe result cache" and delete the probe cache however it doesn't make any difference. Could you tell me what I need to do to have Discovery updatering all the CIs with every Discovery Schedule Job even is the CI has not suffered any update?

Thank you

[Azim Kazi]

Hi Armacar,

there basically 4 phases of discovery

i)   Scanning

ii)  Classification

iii) Identification

iv) Exploration 

 

in scanning phase Shazzam probe triggered and scans infra for port number after this classification occurs in which CIs classified and after that Identification comes in picture in which it check whether CI classified that already present or not if present then it checks any attribute is updating or not if any change found only then then the process goes to exploration phase .otherwise exploration phase has being skipped which is happening in your case.

this is totally out of the box functionality as per ITIL guidelines You can customize this functionality but it will take too much effort and it won't be best practice as it could harm other business cases.

Have look on these articles for further exploration for Discovery:

👉ServiceNow Discovery

👉Port scan/Scanning Phase(troubleshooting)

Hope this will help you.

If my response helps you then kindly mark my answer helpful 👍and correct ✔.if any query 🤔 feel free to ask .

Regards,

Ajim.

[Ashutosh Munot1]

HI,

OOB the field Most Recent Discovery is update for is schedule run and if the CI is seen in schedule.

Do you have any reconciliation rule in place?

Thanks,
Ashutosh

[DaveHertel]

Hi, OOB with Discovery when all is working normally, the "most recent discovery" date will get updated, even if no other field/data changed on the CI.  The discovery source for discovery should also be set to "ServiceNow".  So if you are not seeing the Most Recent Discovery field updated for a given CI, after Discovery runs... then something is wrong.  I'd check the Disco job, logs, and especially the ECC queue input responses to see what going on.

When Disco is running normally, the Most Recent Discovery field is quite handy because you can rely on it to quickly see if a server (or whatever) was recently scanned by Disco (even if there were no other updates to the target).

Hope this helps?

[Armacar2 · Accepted solution]

Hi Dave,

Understood, based on this I will troubleshoot to identify where the issue is. I appreciated it.