Observability

Topology Calculator errors or crashing in the Windows Application Event Log after upgrading to SolarWinds Platform 2024.4 - 2025.1

If you see Topology Calculator errors in the Application Event Log after upgrading to 2024.4 or later, consider decreasing the parallelization of removing the redundancies to prevent the issue.

First published date

2/25/2025 12:32 PM

Last published date

3/20/2025 7:42 PM

Overview

If you see Topology Calculator errors in the Application Event Log after upgrading to 2024.4 or later, consider decreasing the parallelization of removing the redundancies to prevent the issue.

Error example from the log

Error,"10/10/2024 1:00:00 PM",".NET Runtime",(0),MyServer,"Application: SolarWinds.Topology.Calculatorx64.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.Collections.Generic.KeyNotFoundException
   at System.ThrowHelper.ThrowKeyNotFoundException()
   at System.Collections.Generic.Dictionary`2[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]].get_Item(System.__Canon)
   at Amib.Threading.Internal.SynchronizedDictionary`2[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]].get_Item(System.__Canon)
   at Amib.Threading.SmartThreadPool.ProcessQueuedItems()
   at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)
   at System.Threading.ThreadHelper.ThreadStart()

",

Product section

Hybrid Cloud Observability

Cause

This issue occurs due to an unhandled exception during the parallel processing of topology results, primarily when the Topology Calculator removes redundant or duplicated connections.

This issue should not affect the SolarWinds Platform 2024.4, 2024.4.1, and 2025.1 but may place an extra load on the SQL server and related web console pages and widgets.

Resolution

Recommended Resolution: Upgrade to 2025.1.1
A permanent fix for this issue has been implemented in SolarWinds Platform 2025.1.1. The service release is now available for download in the Customer Portal.
 
We highly recommend upgrading to 2025.1.1 to resolve this issue.
 
Alternative Workaround
If an immediate upgrade is not possible, please use the workaround below:

To work around the issue, you can decrease the parallelization of the remove redundancy process to lower the chance of the issue occurring.

Note:

With decreased parallelization, the topology calculation process may take longer.

To decrease the parallelization of the remove redundancy process, complete these steps:

  1. On the main polling engine, navigate to the SolarWinds Observability Self-Hosted installation folder  (C:\Program Files\SolarWinds\Orion\ or C:\Program Files (x86)\SolarWinds\Orion\)
  2. Open the following files in a text editor:
    • SolarWinds.Topology.Calculatorx64.exe.config
    • SolarWinds.Topology.Calculator.exe.config
  3. In both files, change the RemoveRedundancyMaxThreads setting value to 1.
  4. Save the changes and close the files.