SignalR backplane configuration appears to be ignored

[siverson-ivytech]

Description of Issue

We have a HA configuration of Powershell Universal. For a while, we have been experiencing intermittent issues with some of our apps we built not displaying information when queried during and after a rolling deployment. We traced the issue to possibly the use of Sync-UDElement and the use of SignalR. It appears that SignalR is storing state locally on each node, which means that sometimes it gets out of sync between the nodes and fires on the wrong node. We attempted to stand up redis and add this to appsettings.json:

 "SignalR": {
    "Backplane": {
      "Type": "Redis",
      "ConnectionString": "redishost:6379,password=ourpassword"
    }
  }

However, after restarting Powershell Universal, this configuration appears to be ignored, indicating that the SignalR configuration in PowerShell Universal isn't implemented to read this configuration?

Is there another way to share SignalR state between nodes in HA, or is a code change needed?

Version

2026.1.2 (Build 21969895335)

Severity

Medium

Hosting Method

MSI (Windows Service)

Operating System

Windows

Database

SQL

Licensed

Yes

Features

High Availability, Git

Additional Environment data

Windows Server 2022
2 node cluster of Powershell Universal behind HAProxy with sticky connections enabled
Deployments from git using external DevOps CI/CD pipeline

Screenshots/Animations

No response

[siverson-ivytech]

Closing this issue. Currently, PSU does not implement use of Redis for SignalR. After changing the order of our hosts in our deployment pipeline, the issue we were having has not returned, so the need for Redis may not be necessary.