Our Umbraco site is on 8.8.0 and deployed to Azure. Master and Public facing site are deployed to separate instances.

We are seeing 'Lock request time out period exceeded' exceptions in public facing site during setting password. This is happening intermittently. Umbraco.Core.MainDom.Lock = SqlMainDomLock appsetting is already set in web.config.

Stack trace :

System.Data.SqlClient.SqlException:
   at System.Data.SqlClient.SqlConnection.OnError (System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089)
   at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning (System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089)
   at System.Data.SqlClient.TdsParser.TryRun (System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089)
   at System.Data.SqlClient.SqlDataReader.TryHasMoreRows (System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089)
   at System.Data.SqlClient.SqlDataReader.TryReadInternal (System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089)
   at System.Data.SqlClient.SqlDataReader.Read (System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089)
   at NPoco.Database+<Read>d__156`1.MoveNext (NPoco, Version=3.9.4.0, Culture=neutral, PublicKeyToken=null)
   at NPoco.Database+<QueryImp>d__164`1.MoveNext (NPoco, Version=3.9.4.0, Culture=neutral, PublicKeyToken=null)
   at System.Collections.Generic.List`1..ctor (mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089)
   at System.Linq.Enumerable.ToList (System.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089)
   at Umbraco.Core.Persistence.Repositories.Implement.MemberRepository.PersistUpdatedItem (Umbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=nullUmbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=null: D:\a\1\s\src\Umbraco.Core\Persistence\Repositories\Implement\MemberRepository.csUmbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=null: 383)
   at Umbraco.Core.Cache.DefaultRepositoryCachePolicy`2.Update (Umbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=nullUmbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=null: D:\a\1\s\src\Umbraco.Core\Cache\DefaultRepositoryCachePolicy.csUmbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=null: 128)
   at Umbraco.Core.Services.Implement.MemberService.Save (Umbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=nullUmbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=null: D:\a\1\s\src\Umbraco.Core\Services\Implement\MemberService.csUmbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=null: 839)
   at Umbraco.Web.Security.Providers.UmbracoMembershipProvider`2.PerformChangePassword (Umbraco.Web, Version=8.0.0.0, Culture=neutral, PublicKeyToken=nullUmbraco.Web, Version=8.0.0.0, Culture=neutral, PublicKeyToken=null: D:\a\1\s\src\Umbraco.Web\Security\Providers\UmbracoMembershipProvider.csUmbraco.Web, Version=8.0.0.0, Culture=neutral, PublicKeyToken=null: 101)
   at Umbraco.Core.Security.MembershipProviderBase.ChangePassword (Umbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=nullUmbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=null: D:\a\1\s\src\Umbraco.Core\Security\MembershipProviderBase.csUmbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=null: 368)
   at Umbraco.Core.Services.Implement.MemberService.SavePassword (Umbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=nullUmbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=null: D:\a\1\s\src\Umbraco.Core\Services\Implement\MemberService.csUmbraco.Core, Version=8.0.0.0, Culture=neutral, PublicKeyToken=null: 1180)