# OPC UA Connection Failover Error

**URL:** <https://forum.inductiveautomation.com/t/opc-ua-connection-failover-error/107827>\
**Category:** Ignition\
**Created:** [June 26, 2025, 11:17am UTC](https://forum.inductiveautomation.com/t/opc-ua-connection-failover-error/107827 "2025-06-26T11:17:28Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![chandrasekar\_s](https://avatars.discourse-cdn.com/v4/letter/c/8baadc/32.png) [@chandrasekar\_s](https://forum.inductiveautomation.com/u/chandrasekar_s)\
**Post date:** [June 26, 2025, 11:17am UTC](https://forum.inductiveautomation.com/t/opc-ua-connection-failover-error/107827/1 "2025-06-26T11:17:28Z")

</div>

I'm trying to test the Ignition OPC UA connection failover option in the Gateway. I have two Kepware OPC UA servers one primary and one secondary. I have configured the failover option in the Ignition Gateway.

When I stop the primary server, the connection successfully swaps to the secondary failover server. However, I am seeing the following websocket error in the logs:

In this suitation where "Failover Threshold" controls the number of retries before failover, what is the recommended value to balance fast failover vs robustness?  
Would reducing it to 1 improve resilience by failing over faster, or would keeping it at 3 offer better stability by avoiding false failovers due to transient network errors?

| Logger | Time | Message |
| --- | --- | --- |
| ClientSession | 26Jun2025 16:36:21 | Client re-synchronizing. |
| ProjectRunner | 26Jun2025 16:36:13 | Tried to perform RPC operation on an unrecognized session. May indicate that the previous session was lost. Creating RPC listener for new session id. |
| OpcUaConnection | 26Jun2025 16:36:08 | Swapping connection to FAILOVER endpoint |
| OpcUaConnection | 26Jun2025 16:36:08 | Swapping connection to FAILOVER endpoint |
| OpcUaSubscriptionSynchronizer | 26Jun2025 16:36:03 | subscriptionName=tag-group-default\_default, ignSubscription=com.inductiveautomation.ignition.gateway.opcua.client.connection.OpcUaSubscriptionModel$IgnitionSubscription@3e190cd1, opcSubscription=null |
| OpcUaSubscriptionSynchronizer | 26Jun2025 16:36:03 | � |