When Clear is called, sometimes the delete failed with `affected an unexpected number of rows (0)`

[amccool]

System.Data.Entity.Infrastructure.DbUpdateConcurrencyException: Store update, insert, or delete statement affected an unexpected number of rows (0)

Error from storage provider during ClearState for grain Type=Orleans.Streams.PubSubRendezvousGrain Pk=grn/716E8E94/0000000000000000590000000000000006000000716e8e94+BedStreamProvider_BedEvent-22-0x277E9B6A Id=GrainReference:grn/716E8E94/00000000+BedStreamProvider_BedEvent-22 Error=

Exc level 0: System.Data.Entity.Infrastructure.DbUpdateConcurrencyException: Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=472540 for information on understanding and handling optimistic concurrency exceptions. at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Orleans.StorageProviders.SimpleSQLServerStorage.SimpleSQLServerStorage.d21.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Orleans.Core.GrainStateStorageBridge.d8.MoveNext() Exc level 1: System.Data.Entity.Core.OptimisticConcurrencyException: Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=472540 for information on understanding and handling optimistic concurrency exceptions.

[amccool]

since we want to clear to complete, and the rows are 0, we can log this error and continue

[jeoffman]

smells like an un-awaited task