# UDT requires Restart Tag **URL:** \ **Category:** Ignition\ **Tags:** ignition81\ **Created:** [October 5, 2023, 2:48pm UTC](https://forum.inductiveautomation.com/t/udt-requires-restart-tag/80079 "2023-10-05T14:48:06Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Mike\_W\_Mahoney](https://avatars.discourse-cdn.com/v4/letter/m/b19c9b/32.png) [@Mike\_W\_Mahoney](https://forum.inductiveautomation.com/u/Mike_W_Mahoney)\ **Post date:** [October 5, 2023, 2:48pm UTC](https://forum.inductiveautomation.com/t/udt-requires-restart-tag/80079/1 "2023-10-05T14:48:06Z")
I am having trouble with a UDT with several instances. The UDT has three tags with Value Changed scripts, one of which writes activity to a database. They work well for a while and randomly, with no errors in the gateway log, it stops logging. If I "Restart Tag" on the tag and /or "Restart Tag" on the folder, it/they take off and run as expected. I have seen previous posts back when 8.0 was rolled out with stale tags. Is this still a known issue? Is there any recommendations for me to resolve this? Ignition version 8.1.27. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [October 5, 2023, 2:58pm UTC](https://forum.inductiveautomation.com/t/udt-requires-restart-tag/80079/2 "2023-10-05T14:58:35Z")
> [@Mike\_W\_Mahoney](#): > > Is there any recommendations for me to resolve this? Take a Gateway thread dump next time this happens and then call support. [https://docs.inductiveautomation.com/display/DOC81/Diagnostics+-+Threads#DiagnosticsThreads-IndividualThreads](https://docs.inductiveautomation.com/display/DOC81/Diagnostics+-+Threads#DiagnosticsThreads-IndividualThreads) ---
**Author:** ![Mike\_W\_Mahoney](https://avatars.discourse-cdn.com/v4/letter/m/b19c9b/32.png) [@Mike\_W\_Mahoney](https://forum.inductiveautomation.com/u/Mike_W_Mahoney)\ **Post date:** [October 5, 2023, 4:49pm UTC](https://forum.inductiveautomation.com/t/udt-requires-restart-tag/80079/3 "2023-10-05T16:49:39Z")
@Kevin.Herron thank you. I will do this. One question, sometimes we don't catch it immediately... With that being the case, is there a length of time that is too long in terms of when the UDT stops recording and when we get a thread dump that makes the thread dump useless in troubleshooting? If so, we want to be sure to capture a relevant thread dump. Thanks, ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [October 5, 2023, 4:50pm UTC](https://forum.inductiveautomation.com/t/udt-requires-restart-tag/80079/4 "2023-10-05T16:50:58Z")
Maybe. Depends on what the problem is, so I can't answer that for sure. One potential problem is that SQL queries to some databases can hang indefinitely because of poor default timeout values. If that's what's happening I suspect we'll see it in the thread dumps after any amount of time. ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [October 5, 2023, 5:00pm UTC](https://forum.inductiveautomation.com/t/udt-requires-restart-tag/80079/5 "2023-10-05T17:00:20Z")
You really should not be writing directly to any database from a tag's valueChange script. Use the store-and-forward system to decouple your script from any database-generated delays. Some related discussions about the knife edge you are perched upon: [https://forum.inductiveautomation.com/search?q=tag%20event%20single%20digit%20milliseconds](https://forum.inductiveautomation.com/search?q=tag%20event%20single%20digit%20milliseconds) ---
**Author:** ![Mike\_W\_Mahoney](https://avatars.discourse-cdn.com/v4/letter/m/b19c9b/32.png) [@Mike\_W\_Mahoney](https://forum.inductiveautomation.com/u/Mike_W_Mahoney)\ **Post date:** [October 5, 2023, 5:25pm UTC](https://forum.inductiveautomation.com/t/udt-requires-restart-tag/80079/6 "2023-10-05T17:25:22Z")
@pturmel I will look into this as a solution- thank you. Technically, the tag is calling a project script feeding in a few variables. ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [October 5, 2023, 5:29pm UTC](https://forum.inductiveautomation.com/t/udt-requires-restart-tag/80079/7 "2023-10-05T17:29:25Z")
> [@Mike\_W\_Mahoney](#): > > calling a project script Doesn't matter--still ties up the tag event thread, which is one of a limited thread pool.