SmartGWT Custom Events

Ok, so working with the SmartGWT framework on top of Google Web Toolkit. The goal was to fire a custom even from a ToolStrip when one of its members fired a ClickEvent.

This is relatively easily accomplished by subclassing ToolStrip and implementing the HasDataChangedHandlers interface. The only thing that took a bit of time to figure out was that I needed to use the SmartGWT function doAddHandler in BaseWidget instead of the GWT addHandler method in order to properly register the handler with the HandlerManager

Main Class

package test.client;
 
import com.google.gwt.core.client.EntryPoint;
import com.smartgwt.client.data.events.DataChangedEvent;
import com.smartgwt.client.data.events.DataChangedHandler;
 
public class CustomEvents implements EntryPoint {
    public void onModuleLoad() {
        MyStrip t = new MyStrip();
        t.addDataChangedHandler(new DataChangedHandler() {
            @Override
            public void onDataChanged(DataChangedEvent event) {
                // Handle the event here
            }
        });
        t.test();
    }
}

Subclassed ToolStrip

package test.client;
 
import com.google.gwt.event.shared.HandlerRegistration;
import com.smartgwt.client.data.events.DataChangedEvent;
import com.smartgwt.client.data.events.DataChangedHandler;
import com.smartgwt.client.data.events.HasDataChangedHandlers;
import com.smartgwt.client.widgets.toolbar.ToolStrip;
 
public class MyStrip extends ToolStrip implements HasDataChangedHandlers {
 
    public void test() {
        fireEvent(new DataChangedEvent(this.getJsObj()));
    }
 
    @Override
    public HandlerRegistration addDataChangedHandler(DataChangedHandler handler) {
        return doAddHandler(handler, DataChangedEvent.getType());
    }
}

Implementing statistical sampling into the Atlas TDAQ Network

This is my bachelor project while working in the Atlas TDAQ Networking Group, which is a part of the ATLAS experiment on the Large Hadron Collider located at CERN.

The ATLAS data acquisition system consists of four different networks interconnecting up to 2000 processors using up to 200 edge switches and five multi-blade chassis devices. For performance monitoring and troubleshooting purposes there was an imperative need to identify and quantify single traffic flows. sFlow is an industry standard based on statistical sampling which attempts to provide a solution to this.

Due to the size of the ATLAS network, the collection and analysis of the sFlow data from all devices generates a data handling problem of its own.

This report describes how this problem is addressed by developing a system that makes it possible to collect and store data either centrally or distributed according to need, the methods used to present the results in a relevant fashion for system analysts are discussed and we explore the possibilities and limitations of this diagnostic tool, giving some examples of its use in solving system problems that arise during the ATLAS data taking.