# High CPU usage by Netty / OpcUa

**URL:** <https://forum.inductiveautomation.com/t/high-cpu-usage-by-netty-opcua/18257>\
**Category:** Ignition\
**Created:** [June 1, 2018, 6:36am UTC](https://forum.inductiveautomation.com/t/high-cpu-usage-by-netty-opcua/18257 "2018-06-01T06:36:06Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Sanderd17](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/sanderd17/32/8735_2.png) [@Sanderd17](https://forum.inductiveautomation.com/u/Sanderd17)\
**Post date:** [June 1, 2018, 6:36am UTC](https://forum.inductiveautomation.com/t/high-cpu-usage-by-netty-opcua/18257/1 "2018-06-01T06:36:06Z")

</div>

We’re having some issues where the CPU suddenly rises to 50% or even 100% on our Ignition server.

When the OPC Server module is restarted, the CPU usage drops back to single-digit numbers, for a few hours. And then it goes back to 50%.  
 ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/7/76de9424479918c0af8d9dc60a388b347fc15623.png)

When showing the threads, most CPU usage seems to come from the ua-netty-event-loop and the ua-shared-pool threads.

We only have this with one project, and I really don’t know what’s different between this project and the others.

 ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/3/356df43d45a5ab892683699ca5b03f5c07c13c42.png)