Orion Platform

Polling engines become unresponsive in SolarWinds Platform 2026.1 due to high UDP port usage

In the SolarWinds Platform 2026.1 release, some polling engines that are members of High Availability pools using a virtual hostname can become unresponsive because the High Availability Service opens and maintains a large number of UDP connections. Over time, this behavior exhausts available ports on the server, causing connectivity issues until the service is restarted.

First published date

2/27/2026 1:19 AM

Last published date

4/10/2026 3:13 PM

Overview

In 2026.1, on polling engines that are members of a High Availability pool configured with a Virtual Hostname, the High Availability service will, over time, open UDP ports in the dynamic range until all available ports on the server are consumed. Once port exhaustion occurs, the server experiences connectivity failures and polling disruption, requiring either a server reboot or a restart of the High Availability service to restore normal operation. This behavior does NOT affect HA pools configured with a VIP only, or with Virtual IP and Virtual Hostname disabled.

 

Symptoms:

  • Polling engines are not accessible via RDP
  • General connectivity issues
  • Polling failures and data gaps
  • Sluggish or unresponsive web console if running on the Main Poller
  • Server Crash
  • Intermittent Failover

 

 

 

 

Product section

Orion Platform

Cause

This issue was due to the DNS function used by the Virtual Hostname.  This issue is only applicable to SolarWinds Platform 2026.1.

Resolution

To resolve this issue, please upgrade to SolarWinds Platform 2026.1.1 and above.

If an upgrade is not possible, perform one of the workarounds below: 

 

  1. Submit a ticket to apply a Buddy Drop for Solarwinds Platform 2026.1 with the assistance of SolarWinds Support.

       2.  To stop this behavior, remove the Virtual Hostname from the HA pool. If your pool is configured with both a VIP and a Virtual Hostname, you can remove the hostname and save the pool with only the VIP. If the pool is configured with only a Virtual Hostname, use the toggle to disable it while leaving the pool itself intact. Afterwards, the High Availability Service will no longer continuously open UDP ports. You'll need to restart the High Availability Service to release the ports that were in use.

 

  • Without a Virtual Hostname or VIP, inbound traffic (NetFlow/Syslog/Traps) will not follow a failover.
  • If the Virtual Hostname is used for web console access, it will not work after a failover. The server name or IP address can be used as a temporary workaround.