"Generic SQL error and SQL timeout expired" by Assigning user Access Team

Hello Experts,

first I hop I can find here an answer.

Steps:

We got the following error when we try to assign users an Access Team using OdataCall.

We generated more than million OcataCall which assigns  50 users to an Access Team.

We are using Multi-Threading (30 Threads) that's means 30 Requests are sent simultaneously to CRM. 

Problem:

50% of request are not successfully bekoz we got the following Error.

Http Response: Async CRM Call was rejected.
Response Header: {"lines":{"Cache-Control":"no-cache","Pragma":"no-cache","Content-Type":"application/json; odata.metadata=none","Expires":"-1","Server":"Microsoft-IIS/8.5","REQ_ID":"6f1e5793-180c-4fd9-b92f-53a9b6de0652","OData-Version":"4.0","X-AspNet-Version":"4.0.30319","Persistent-Auth":"true","X-Powered-By":"ASP.NET","Date":"Mon, 05 Nov 2018 09:58:00 GMT","Content-Length":"2823"},"status":"500","statusMessage":"Internal Server Error"}
Payload Out: {
  "error":{
    "code":"","message":"Generic SQL error.","innererror":{
      "message":"Generic SQL error.","type":"System.ServiceModel.FaultException`1[[Microsoft.Xrm.Sdk.OrganizationServiceFault, Microsoft.Xrm.Sdk, Version=8.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]]","stacktrace":"   at Microsoft.Crm.Extensibility.OrganizationSdkServiceInternal.Execute(OrganizationRequest request, CorrelationToken correlationToken, CallerOriginToken callerOriginToken, WebServiceType serviceType, Boolean checkAdminMode, ExecutionContext executionContext)\r\n   at Microsoft.Crm.Extensibility.OData.CrmODataServiceDataProvider.ExecuteOperation(CrmODataExecutionContext context, EdmOperation edmOperation, Dictionary`2 parameters, Dictionary`2 boundParameters)\r\n   at Microsoft.Crm.Extensibility.OData.ActionController.ProcessOperationRequest(String operationName, Dictionary`2 operationParameters, EntityReference entityReference, String boundEntityName, String boundEntityType)\r\n   at Microsoft.Crm.Extensibility.OData.ActionController.PostBoundAction(String entityName, String key, String operationName, ODataUntypedActionParameters parameters)\r\n   at lambda_method(Closure , Object , Object[] )\r\n   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass10.<GetExecutor>b__9(Object instance, Object[] methodParameters)\r\n   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary`2 arguments, CancellationToken cancellationToken)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n   at System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n   at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n   at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()"
    }
  }

Http Response: Async CRM Call was rejected.
Response Header: {"lines":{"Cache-Control":"no-cache","Pragma":"no-cache","Content-Type":"application/json; odata.metadata=none","Expires":"-1","Server":"Microsoft-IIS/8.5","REQ_ID":"5bf9ea09-3c6b-46d8-8b44-01fb433426a7","OData-Version":"4.0","X-AspNet-Version":"4.0.30319","Persistent-Auth":"true","X-Powered-By":"ASP.NET","Date":"Mon, 05 Nov 2018 09:57:58 GMT","Content-Length":"2827"},"status":"500","statusMessage":"Internal Server Error"}
Payload Out: {
  "error":{
    "code":"","message":"SQL timeout expired.","innererror":{
      "message":"SQL timeout expired.","type":"System.ServiceModel.FaultException`1[[Microsoft.Xrm.Sdk.OrganizationServiceFault, Microsoft.Xrm.Sdk, Version=8.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]]","stacktrace":"   at Microsoft.Crm.Extensibility.OrganizationSdkServiceInternal.Execute(OrganizationRequest request, CorrelationToken correlationToken, CallerOriginToken callerOriginToken, WebServiceType serviceType, Boolean checkAdminMode, ExecutionContext executionContext)\r\n   at Microsoft.Crm.Extensibility.OData.CrmODataServiceDataProvider.ExecuteOperation(CrmODataExecutionContext context, EdmOperation edmOperation, Dictionary`2 parameters, Dictionary`2 boundParameters)\r\n   at Microsoft.Crm.Extensibility.OData.ActionController.ProcessOperationRequest(String operationName, Dictionary`2 operationParameters, EntityReference entityReference, String boundEntityName, String boundEntityType)\r\n   at Microsoft.Crm.Extensibility.OData.ActionController.PostBoundAction(String entityName, String key, String operationName, ODataUntypedActionParameters parameters)\r\n   at lambda_method(Closure , Object , Object[] )\r\n   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass10.<GetExecutor>b__9(Object instance, Object[] methodParameters)\r\n   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary`2 arguments, CancellationToken cancellationToken)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n   at System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n   at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n   at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()"
    }
  }
}

Please also let me know what is the best way to solve this problem.

Regards,

Adil