/EPiServer/cms/Stores/contentstructure/?referenceId=XXX&query=getchildren&typeIdentifiers=episerver.core.pagedata&allLanguages=true&sort()&dojo.preventCache=1554387618898

is another killer

@Khurram - can you run a profiler such as dotTrace for those requests to see which are in there?

This won't be possible, Its production, it's Azure, Its a large DB.

Then you can use Application Insights and memory dumps to find out what is slow :)

The developer support service is there!

Are you sure that works in the DXC Service version of Application Insights @Quan?

Which works? 

Khurram just said about Azure, nothing about DXC-S. Honestly I don't know what you can access with DXC-S, but you can always reach out for support

as an immediate remedy, we restarted applications. it solved the issue but it's under observation now. There is another weird issue that I am having on Release on few environments. To fix that only option that I have is Stop Application/Delete ww root folder and deploy again. But this is I have to do for every release. I am looking into this now but don't have any clue yet.

The argument 'nameOrConnectionString' cannot be null, empty or contain only white space.
....

[ArgumentException: The argument 'nameOrConnectionString' cannot be null, empty or contain only white space.]
   System.Data.Entity.Utilities.Check.NotEmpty(String value, String parameterName) +79
   System.Data.Entity.DbContext..ctor(String nameOrConnectionString) +34
   DbLocalizationProvider.LanguageEntities..ctor(String connectionString) +17
   DbLocalizationProvider.AspNet.Queries.GetResourceHandler.Execute(Query query) +105
   DbLocalizationProvider.AspNet.Queries.GetTranslationHandler.Execute(Query query) +538
   DbLocalizationProvider.EPiServer.DatabaseLocalizationProvider.GetString(String originalKey, String[] normalizedKey, CultureInfo culture) +90
   EPiServer.Framework.Localization.ProviderBasedLocalizationService.LoadString(String[] normalizedKey, String originalKey, CultureInfo culture) +122
   EPiServer.Framework.Localization.LocalizationService.TryGetStringByCulture(String originalKey, String[] normalizedKey, CultureInfo culture, CultureInfo fallbackCulture, String& localizedString) +140
   EPiServer.Framework.Localization.LocalizationService.GetStringByCulture(String resourceKey, FallbackBehaviors fallbackBehavior, String fallback, CultureInfo culture) +321
   EPiServer.Framework.Localization.LocalizationService.GetStringByCulture(String resourceKey, FallbackBehaviors fallbackBehavior, CultureInfo culture) +22
   EPiServer.Framework.Localization.LocalizationService.GetString(String resourceKey) +70
   EPiServer.Forms.EditView.InitializationModule.SetupFormContainerProperties() +708
   EPiServer.Forms.EditView.InitializationModule.Initialize(InitializationEngine context) +192
   EPiServer.Framework.Initialization.Internal.ModuleNode.Execute(Action a, String key) +58
   EPiServer.Framework.Initialization.Internal.ModuleNode.Initialize(InitializationEngine context) +123
   EPiServer.Framework.Initialization.InitializationEngine.InitializeModules() +248

[InitializationException: Initialize action failed for Initialize on class EPiServer.Forms.EditView.InitializationModule, EPiServer.Forms.UI, Version=4.23.0.0, Culture=neutral, PublicKeyToken=8fe83dea738b45b7]
   EPiServer.Framework.Initialization.InitializationEngine.InitializeModules() +774
   EPiServer.Framework.Initialization.InitializationEngine.ExecuteTransition(Boolean continueTransitions) +194
   EPiServer.Framework.Initialization.InitializationModule.EngineExecute(HostType hostType, Action`1 engineAction) +861
   EPiServer.Framework.Initialization.InitializationModule.FrameworkInitialization(HostType hostType) +185
   EPiServer.Global..ctor() +42
   ASP.global_asax..ctor() +9

Above issue "name or connection string" is sorted, Just install Latest DBLocalization Provider.

https://github.com/valdisiljuconoks/localization-provider-epi/commit/e840f0cb7fcbf5101b11a235be0ebed37bd509ac

The performance issue isn't solved, we are having this issue about after 7 days after a recycle. we don't recycle each night. I am going to raise this with support.

/K