In Global.asax, the following code starts the orderpipeline when application starts.

    void Application_Start(object sender, EventArgs e) {
        OrderPipelineController.Start();
    }

It would load DataRefresh task defined in your web.config.

    <taskConfiguration defaultProvider="">

        <providers>

            <add name="DataRefresh" type="DotShoppingCart.OpenSource.OrderPipeline.DataRefreshTaskProvider, DotShoppingCart.OpenSource.OrderPipeline" />

        </providers>

    </taskConfiguration>

DataRefresh would update your category  counter every 2 hours.

    protected override void RunTask(string host, IConfigurationSource cfgSrc) {

        Category.UpdateProductCount(host);

    }