We have years worth of historical queue data in a Microsoft Sql database and the same tables that contain this historical data also keep track of pending or currently active work. Here's a highly simplified visual example. TypeSubtypeStatusParameters ExportEmailComplete"From: noreply@foo.com, To: someone@bar.com" ImportExcelActive"FilePath: c:\import.xls" ImportWebPending"Url: http://google.com" This structure leaves us with several issues: Contention: To handle volume we have many windows serv[...]