After clearing the nas database tables to resync nas to UIM database, nas alarm processing is very slow.

Products

• DX Unified Infrastructure Management (Nimsoft / UIM)

Issue/Introduction

After following the steps in the below article to force a resync between the local nas database and the UIM nas tables, the nas alarm processing became very slow (about 1 alarm per 5 seconds).  

nas alarms are not 'in sync' between UMP (USM)/OC and Infrastructure Manager (IM)

This is causing the alarm queue to grow when alarms coming in faster than processed.

In the nas.log file, errors similar to the following are observed:

nas: nsLookup ip:<Hostname> => '<FQDN' in xxxxms

If the number of ms is very high, this will cause delays in alarm processing.

Environment

UIM 20.4
nas 9.xx

Cause

Nas probe does a nslookup on the ip address in each alarm.  The database.db file has a name_service table to cache previous nslookup results.  These must complete before moving on to the next alarm for processing.

Resolution

The cached entries of the old database.db file can be imported to the new database.db file.  This will allow the nslookup refresh to not occur for every alarm.

1. Using a tool like HeidiSQL or DB Browser for SQLite, open the old database.db file.
2. Export the NAS_NAME_SERVICE table from the backup of database.db.
3. Stop the nas probe
4. Open the new database.db file
5. Empty the NAS_NAME_SERVICE table (to avoid duplicates)
6. Import the backup NAS_NAME_SERVICE table (from step 2) to the new database.db file
7. Start nas

This will allow the nas probe to use the previously cached nslookup entries and not need to validate the ip address in every alarm.

You can also increase the time to revalidate the name entries from 1h (default) to 1d or more if needed to allow more time between revalidation.

Additional Information

If the time in the log for nslookup is greater than 2-3 seconds (2000-3000ms), there may be issues with nslookup from this server.  Please confirm that the dns lookups are responding quickly enough.