Thursday 6th June 2019

WinBooks on Web SQL performance degradation for WinBooks on Web

For an unknown reason there is a resource exhaustion on our SQL engine of WinBooks on Web.

We set the application in maintenance until it's fixed. The maintenance page will redirect you once the maintenance is ended.


  • 08:45 - an automated sql index maintenance task has gone wild exhausting all resources of the vm.
  • 08:45 - the task has been stopped, resources are released.
  • 08:50 - the maintenance is removed

After analyzing our monitoring data, the issue has started around 04:30 with a large burst of memory usage, beyond the limit assigned to the SQL engine. We have updated our monitoring system to catch this situation.