Webswing.log Warnings After DX NetOps Spectrum Upgrade

Products

• Network Observability
• Spectrum

Issue/Introduction

After upgrading DX NetOps Spectrum, the $SPECROOT/webtomcat/bin/logs/webswing.log file may show thousands of warning messages similar to the following, and the OneClick web client will not display.

2026-03-24 15:40:51,155 WARN [Webswing Websocket Handler] (SessionPoolImpl.java:243) Connected to server [wss://<hostname>:9444/spectrum] rejected! Closing connection...
2026-03-24 15:40:51,155 WARN [Webswing Websocket Handler] (SessionPoolImpl.java:245) Reason: Session pool with id [<hostname>] already registered!


Additionally in the webswing.log two different versions of webswing cluster are seen initializing (the versions will vary)

2026-03-24 15:53:50,409 INFO  [main] (ClusterServlet.java:76) Initializing Webswing Cluster 25.2.4 
~~~~~~
2026-03-24 15:53:54,996 INFO  [main] (ClusterServlet.java:76) Initializing Webswing Cluster 25.1.1

Environment

Spectrum, all supported versions

Cause

This issue typically occurs due to duplicate or stale files in the webtomcat webapps directory, such as a backed-up spectrum.war file or an extra directory from a previous installation or hot-fix. These duplicates cause Webswing to attempt multiple registrations for the same session pool ID when the multiple versions are initialized.

Resolution

To resolve this issue, ensure only the required files and directories are present in the $SPECROOT/webtomcat/webapps directory.

Steps to Clean the Webapps Directory

This command will make changes to your system. Review it carefully before running.

1. Stop the webtomcat service, as the spectrum installation owner:
   • cd $SPECROOT/webtomcat/bin
   • ./stopWebTomcat.sh
2. Navigate to the $SPECROOT/webtomcat/webapps directory.
3. Verify the contents of the directory. The only files and directories that should be present are:
   • admin (directory)
   • admin.war
   • spectrum (directory)
   • spectrum.war
   • webswing-autoscaling.config
4. If an extra .war file (e.g., a backup or differently named spectrum WAR) and its corresponding directory are present:
   • Delete the spectrum directory (leave the spectrum.war file).
   • Delete the extra, differently named .war file and its extracted directory.
5. Start the webtomcat service.
   • cd $SPECROOT/webtomcat/bin
   • ./stopWeboOmcat.sh

Upon restart, the spectrum directory will be re-extracted from the valid spectrum.war file, and the duplicate registration warnings should cease .