Hello Our

We have an issue with a couple of our websites, which keeps randomly going down.

The exception in the log is this:

{"@t":"2024-09-24T22:00:04.2700471Z","@mt":"An unhandled exception occurred","@l":"Error","@x":"Umbraco.Core.Exceptions.BootFailedException: Boot failed: Umbraco cannot run. See Umbraco's log file for more details.\n\n-> Umbraco.Core.Exceptions.BootFailedException: Boot failed.\n\n-> System.TimeoutException: Cannot acquire MainDom\n   at Umbraco.Core.Runtime.MainDom.Acquire() in D:\\a\\1\\s\\src\\Umbraco.Core\\Runtime\\MainDom.cs:line 172\r\n   at Umbraco.Core.Runtime.MainDom.<get_IsMainDom>b__16_0() in D:\\a\\1\\s\\src\\Umbraco.Core\\Runtime\\MainDom.cs:line 211\r\n   at System.Threading.LazyInitializer.EnsureInitializedCore[T](T& target, Boolean& initialized, Object& syncLock, Func`1 valueFactory)\r\n   at Umbraco.Core.Runtime.MainDom.get_IsMainDom() in D:\\a\\1\\s\\src\\Umbraco.Core\\Runtime\\MainDom.cs:line 211\r\n   at Umbraco.Core.Runtime.CoreRuntime.AcquireMainDom(IMainDom mainDom) in D:\\a\\1\\s\\src\\Umbraco.Core\\Runtime\\CoreRuntime.cs:line 471\r\n   at Umbraco.Core.Runtime.CoreRuntime.Boot(IRegister register, DisposableTimer timer) in D:\\a\\1\\s\\src\\Umbraco.Core\\Runtime\\CoreRuntime.cs:line 180\r\n   at Umbraco.Core.Exceptions.BootFailedException.Rethrow(BootFailedException bootFailedException) in D:\\a\\1\\s\\src\\Umbraco.Core\\Exceptions\\BootFailedException.cs:line 80\r\n   at Umbraco.Web.Composing.ModuleInjector`1.<>c__DisplayClass4_0.<Init>b__0(Object sender, EventArgs args) in D:\\a\\1\\s\\src\\Umbraco.Web\\Composing\\ModuleInjector.cs:line 44\r\n   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()\r\n   at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)\r\n   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)","SourceContext":"Umbraco.Web.UmbracoApplicationBase","ProcessId":12492,"ProcessName":"w3wp","ThreadId":52,"AppDomainId":2,"AppDomainAppId":"LMW3SVC19ROOT","MachineName":"EC2AMAZ-PNTVJAN","Log4NetLevel":"ERROR","HttpRequestNumber":590,"HttpRequestId":"7b17e459-44a7-4d88-8e31-0bdf5fbc32dc"}

My thought is that this is due to a timeout on the database server, however the database does not have any spikes or low ressource availability when this happens.

Umbraco version is 8.18.13

Any ideas on how to debug this further?