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Debug Identification Engine errors when data is splitted in multiple ECC pages

Import · Nov 09, 2023 · article
  • If I have issues to find the an identification error if hidden in Discovery creating multiple pages of results
    • In case the data is in one page, you can use this page, but most steps are not relevant

Note : The missing log page issue will be fixed in Washington Release (PRB1672012). If you are using this release, step 3 should be not needed.

Issue

  • When discovery is completed, and there a a lot of data, the data might be splitted in multiple pages
  • If an identification of a single page fails, the total discovery will fail
  • From the logs, you can see the proceesed pages, but not every time the page thats is failing

How to solve the issue

  • Step 1 : Use the specific UI page
  • Step 2 : Simulate the identification of the follwing page

Example of a real debug situation

Step 1 : Something is wrong with the Kubernetes pattern.

Note : When Pattern fails, first thing to do is to display pattern log, to understand when the issue happened (is it on the MID, on the instance, which step....)

BenoitCrestey_0-1699375916918.png

Step 2 : We can see in the log that discovery was fine, but we had an issue in Identification step

Note : We can see the error, but sadfuly, the page is not displayed... This is the reason why I created the custom UI Page, that will try to find the missing pages.

BenoitCrestey_1-1699375957137.png

Step 3 : Use the UI page

Note : This step shouldn't be required from W release

  • Go to the custom UI page
    • Note : you can go using the UI page and Try, or create a Favorite, or create a Menu if needed
  • Paste directly the text of the Log
    • By doing "Select All" and then "Copy" from logs
    • Then "Paste" in the text box
  • Then hit the button "Search for missing page"
  • Then we can see if a page is missing
    • In my example, page 4 is missing
    • In means that there were errors on page 4

BenoitCrestey_2-1699375988251.png

Step 4 : Go in the ECC Queue Tab to get the Page 4

BenoitCrestey_3-1699376074122.png

Step 5 : Grab the text

Note : Can be in an attached file

BenoitCrestey_5-1699376157645.png

Step 6 : Cut the text to keep after "results" : and before }

BenoitCrestey_6-1699376207643.png

Step 7 : Go in Identification Simulation, from the ServiceNow menu, and select "Start with existing Payload"

BenoitCrestey_7-1699376263059.png

Step 8 : Select "ServiceNow" as Data Source if source is discovery, and paste the payload

BenoitCrestey_8-1699376321238.png

Step 9 : Error should be in the logs

Note : if you don't have any error, perhaps the CMDB data changed since the test

Note 2 : sometimes, the error is hidden far in the logs

BenoitCrestey_9-1699376563158.png

Step 10 : Solve the issue

  • On this specific exemple, from the logs I can see the reason of the failure :
    • A duplicate relationship exist in the CMDB, relating the 2 sames CIs, with the same type of relationship
      • This situation is problematic, as IRE will fail to update. When it will receive the relationship again, it will fail because it doesn't know which one to update
  • Temporary fix : delete one of the relationships
  • Long term fix : Open a case to ServiceNow
  • Long term fix alternative : Develop a script to search and delete duplicates

BenoitCrestey_0-1699377171667.png

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View original source

https://www.servicenow.com/community/itom-articles/debug-identification-engine-errors-when-data-is-splitted-in/ta-p/2723547