Framework: Grid Sort calls sizeInBackEnd and fetchFromBackEnd too often

[knoell-it-service]

Vaadin Version: 8.7.1
Browser: Chrome 73.0.3683.86
Web container: Payara Server 4.1.2.181 #badassfish (build 220)

Description: A user-triggered sorting of a simple column calls the dataprovider too often. This creates unnecessary traffic. Possible origin could be the DataCommunicator.

List<Integer> data = new ArrayList<>();
data.add(0);
data.add(1);
data.add(2);

Grid<Integer> grid = new Grid<>();
grid.addSortListener(event -> {
    System.out.println("ON SORT " + event.getComponent().getCaption() + " - " + event.getSortOrder().toString());
});
grid.addColumn(Integer::valueOf).setCaption("ID").setId("id").setSortable(true).setSortProperty("id");

grid.setDataProvider(DataProvider.fromCallbacks(query ->{
    System.out.println("FETCH");
    if(query.getSortOrders().size() > 0) {
        System.out.println("SORT BY " + query.getSortOrders().get(0).getSorted());
    }
    return data.stream();
}, query -> {
    System.out.println("SIZE");
    if(query.getSortOrders().size() > 0) {
        System.out.println("SORT BY " + query.getSortOrders().get(0).getSorted());
    }
    return data.size();
}));

Expectation:

• Event call
• sizeInBackEnd (optional)
• fetchFromBackEnd

Actual behavior:
Log:

SIZE
FETCH
SIZE
SIZE
FETCH - SORT BY id
SIZE
ON SORT null - [com.vaadin.data.provider.GridSortOrder@66ad843d]]
FETCH - SORT BY id

Issue not existent in Vaadin Flow.

[cardhoder]

Same problem, Vaadin version 8.8.0. This makes back-end backed grid unusable.

[corderhader]

Vaadin version 8.8.0, causes grid to be unusable.

[broejew]

I too would like to see this issue fixed as it results in very slow loading of data in the grid component

[Kalomo]

Please investigate on that issue, we also have the feeling that the grid is very slow when a user-triggered sorting is called