Question

We’ve come across a slight issue with loading of multiple partial views via Ajax that I can’t narrow down.

The page loads 6 partial views on the click of a button.

We originally had the partial views rendered on a single page by the server, however this meant that the processing ran in series and the page didn’t return very quickly.

So I created a little bit of javascript that would run and async ajax request to refresh them all (note that the partial view url is rendered in the markup to make this easier, temporarily).

function refreshAllPartials() {
    $('div.partial').each(function () {
        var partialView = $(this);
        var partialViewUrl = $(partialView).attr('partialUrl');
        var parent = $(partialView).parent();
        $(parent).empty();
        $.ajax({
            url: partialViewUrl,
            type: "GET",
            async: true,
            success: function (response, textStatus, jqXHR) {
                $(parent).html(response);
            }
        });
    });
}

Now, the issue is that although the each of the partial view requests takes around 0.7s to return (checked using Fiddler), the output from Firebug shows something thing different.

The output from fiddler is consistent within a few milliseconds, however the firebug output and the visual effect to the user, seem to keep changing.

I’m guessing there is something I’m missing about how the javascript works, and how rendering works, but maybe I’m just doing something wrong?

I’m using ASP.NET MVC3, however, I’m not sure it’s relevant as Fiddler is showing that IIS is returning the data in a timely manner.

Answer 1

This issue is that the controller actions are not marked as only requiring Read access to the Session state.

There is an “feature” of the SessionState in ASP.NET that only 1 request can have exclusive access the session, and all other requests are then “queued” behind it.

All I needed to do was separate the action methods that do not need Write access to the session into another controller and add:

[SessionState(System.Web.SessionState.SessionStateBehavior.ReadOnly)]

as an attribute to the new controller.

viola, very performant site now, very snappy.