What is the Impact of Restarting the NAS Probe in DX UIM

Products

• DX Unified Infrastructure Management (Nimsoft / UIM)

Issue/Introduction

What is the operational impact on the monitoring environment when the nas probe is restarted? Is there a risk of alarm data loss?

Environment

DX Unified Infrastructure Management (DX UIM), any version
Component: nas (Network Alarm Server) probe, any version

Cause

Sometimes, a restart of nas is required as part of a maintenance activity or a change in the configuration. The impact of such restart is not clearly identified in the probe documentation, hence the reason of creating this article.

Resolution

Restarting the nas probe is a standard administrative action that is safe and self-healing. There is no loss of alarm data during a routine restart. However, administrators should expect the following temporary impacts while the probe is down and during its initialization phase:

1. Alarm Queueing and Retention

When the nas probe shuts down, the Primary Hub temporarily holds all incoming alarms in the message bus queue (specifically the alarm subject queue).
Once the nas probe starts back up, it automatically reconnects to the message bus and rapidly drains the queue, processing the backlog of alarms. No alarms are dropped during this period.

2. Auto-Operator and Ticketing Delays

All automated actions driven by the nas probe are suspended while the probe is offline. This includes the following:

- Notifications & Ticketing: Auto-Operator profiles configured to send emails, SMS, or route alarms to the sdgtw gateway (for Service Desk tickets) will pause. These queued actions will trigger as soon as nas processes the backlog upon startup.

- Time-Over-Threshold Rules: Rules configured to wait for an alarm to exist for a specific duration (e.g., 15 minutes) may have their internal timers reset or skewed depending on the exact duration of the restart.

3. Interruption of LUA Scripts

- Active Scripts: Any custom LUA scripts driven by the nas Auto-Operator that are actively executing at the exact moment the restart command is issued will be abruptly terminated.

- Scheduled Scripts: Any scripts scheduled to run during the exact window the probe is offline will be missed and will not retroactively execute upon startup.

4. Frontend UI Disruption

- Alarm views in frontend dashboards rely entirely on the continuous operation of the nas probe.

- User Impact: Users actively viewing the Operator Console, DX Dashboards, or the legacy Infrastructure Manager will experience a temporary freeze in new incoming alarms. The console may briefly display a "disconnected from nas" or "loading" message until the probe fully re-establishes its connection.

5. Database Synchronization (NiS Bridge)

The nas probe utilizes the NiS bridge to write historical alarm data and transaction states to the backend database (e.g., the NAS_ALARM and NAS_TRANSACTION_SUMMARY tables).

This synchronization pauses during the restart. Upon startup, the nas NiS bridge will re-initialize its connection to the database and flush its cached transactions. This results in a brief delay before the newest alarm history becomes visible or searchable via direct SQL queries.

Additional Information

A standard restart of the nas probe is non-destructive. The primary impact is a brief, temporary delay in alarm visibility, automated notifications, and external ticketing while the probe catches up on the message queue.