Kendo Grid Row Filters inputs use autocomplete by default. Because of this the data source is queried on every keystroke in the auto complete. This causes unacceptable performance issues with a large/complex server side data source. I suggest adding a configuration to turn this off, which would cause the data source to only be queried on an enter keystroke.
This is already supported, folks. You can specify columns.filterable.cell.minLength (http://docs.telerik.com/kendo-ui/api/javascript/ui/grid#configuration-columns.filterable.cell.minLength) to 'tell' the min length of the typed pattern before the autocomplete triggers a request to its data source. Alternatively, you can utilize the columns.filterable.cell.delay property (http://docs.telerik.com/kendo-ui/api/javascript/ui/grid#configuration-columns.filterable.cell.delay), if applicable.
This sounds like a great feature that we could use on large data sources where it would be expensive to go back to the server on every key entry but still want to give our users the ability to enter a filter quickly. Great suggestion!