Applications Systems

Instance availability alert does not trigger

This article explains what to do when a monitored database instance goes down but the availability alert either does not fire or triggers with a delay after the instance becomes unreachable.

First published date

11/1/2018 5:40 PM

Last published date

12/15/2025 8:17 PM

Overview

The database instance availability alert is often configured with a short interval (such as 1 minute). However, when the instance goes down, the alert may not trigger immediately or may delay firing after the connection to the instance is lost.

Starting with DPA 2025.4, by default, the alert is now triggered the first time DPA is unable to connect to the monitored instance (the default number of retries is 0). If you would like the alert to be triggered only after multiple consecutive connection attempts fail, set the advanced configuration option ALERT_CONNECTION_ATTEMPTS. 

 

Note:

If you upgrade to DPA 2025.4 or later and had previously configured ALERT_CONNECTION_ATTEMPTS, your existing setting is preserved.

 

Product section

Database Performance Analyzer

Cause

Historically, this alert sometimes generated false positives because it triggered based on connection attempts to the instance. For the alert to fire:

  • Monitoring must be enabled for the instance.

  • The connection to the database server must fail.

By default, earlier DPA versions:

  • Sampled connectivity every 90 seconds

  • Required three consecutive failed connection attempts, each spaced 90 seconds apart, before triggering the alert

This design helped reduce false alerts but could delay notification by several minutes.

In DPA 2025.4, improvements were introduced to allow the alert to trigger more promptly when a connection failure is detected.

Resolution

You can configure the alert polling interval and the number of failed connection attempts before the alert fires:
  1. Navigate to:
    Options > Administration tab > Advanced Options > DB Instance Options tab
  2. Select the database instance you want to configure from the drop-down menu.
  3. Adjust the following settings as needed:
    • ALERT_CONNECTION_INTERVAL — the polling interval in seconds (default: 90)
    • ALERT_CONNECTION_ATTEMPTS — number of consecutive failed connection attempts before alerting (default: 3 prior to DPA 2025.4; 0 starting with DPA 2025.4)
  4. Save your changes.
Adjust these values to balance between minimizing false alerts and ensuring timely notifications based on your environment’s needs.