Debugging SSIS Script Tasks

SSIS Script tasks provide codes to implement customized functions that a built-in SSIS task cannot achieve directly. It is often necessary to debug through a Script task to ensure it works properly. You can set breakpoints for events such as OnPreExecute or OnPostExecute from ten break conditions as we discussed in Set Breakpoints for SSIS Debugging. Moreover, you can define stopping points in a script task through Microsoft Visual Studio Tools for Applications (VSTA).

Set a breakpoint in VSTA for a Script Task?

After you click “Edit Script” button in Script Task, a VSTA window will open.

Click the line you would like to set a breakpoint. Then right-click it and select Breakpoint –> Insert Breakpoint.

Below shows setting breakpoints in SQL Server 2008 R2.

Now you have the breakpoint set right before Messagebox.Show(). This means that the execution should break immediately before the message box is popped up.

SQL Server 2012

The way to set breakpoints in Script Tasks for SQL Server 2012 is similar as shown.

Also, after clicking Insert Breakpoint, a popup window will let you to do more fine tunings for your breakpoint through locations of Line and Character.

Note that SQL Server 2012 has one additional option: Insert Tracepoint besides “Insert Breakpoint”.

 

How breakpoints work?

After you set up the breakpoint, you can close Script Task Editor window. Right Click the Script Task and then select Execute Task. You would expect a yellow arrow displayed at the breakpoint.

After you press F10 button, a message box pops up with the message “Hello World”. After you close the popup window, the VSTA window should appear like this.

Tweaks for SQL Server 2008

If you use SQL Server 2012, you are lucky to get the breakpoint hit as described above.

If you use SQL Server 2008, you need some tweaks to make breakpoints working as expected:

Step 1: Set SSIS runtime mode as 32 bit at PROJECT Level.

Step 2: Re-open Script Task Editor window and save it again. In this way, your script task code is set to be compiled as 32 bit.

 

Shortcut Keys for Debugging

You can use debugger shortcut keys to speed up debugging. SSIS Script tasks share the same set of shortcut keys for Visual Studio. Here is a list of some common shortcut keys.

Keys	Functions
F5	Run the application.
F10	Step Over (Execute the next line of codes but not follow execution through any function calls).
F11	Step Into.
SHIFT+F11	Step Out.
CTRL+BREAK	Stop execution (Break).
F9	Toggle breakpoints.

Now I hope that you have a solid understanding of how to debug script tasks in SSIS. Take time to play with it and you will find it save the day for you in troubleshooting. If you have any questions, please feel free to leave a comment.

Reference:

1. Debug a Script by Setting Breakpoints in a Script Task and Script Component
2. Debugger Shortcut Keys for Visual Studio

Set Breakpoints for SSIS Debugging

Like debugging codes for other languages or tools, it is often necessary to set breakpoints to pause execution so you can examine variable values where you think the problem can be. SSIS provides a very straightforward GUI to help you set breakpoints in SSIS packages.

Where to set breakpoints?

You can set breakpoints on a task or a container. A task can be Execute SQL Task, data flow tasks, script tasks, etc. A container can be a For Loop container, a Foreach Loop container, or a Sequence container.

Moreover, there are eleven break conditions that you can choose from as shown below

These break conditions are defined as:

1. OnPreExecute: Called by a task or a container immediately before it runs.
2. OnPostExecute: Called by a task or a container immediately after it runs.
3. OnError: Called by a task or container when an error occurs.
4. OnWarning: Called when the task is in a state that does not justify an error, but does warrant a warning.
5. OnInformation: Called when the task is required to provide information.
6. OnTaskFailed: Called by the task host when it fails.
7. OnProgress: Called when there is measurable progress about task execution.
8. OnQueryCancel: Called at any time in task processing when a cancel execution is fired.
9. OnVariableValueChanged: Called when the value of a variable changes. The RaiseChangeEvent of the variable must be set to true to raise this event.
10. OnCustomEvent: Called by a custom task-defined events.
11. Loop iterations: Called when the iteration condition in a loop is satisfied. This only appears for a For Loop container and a Foreach Loop container.

Moreover, there are four Hit Count types you can define:

• Always
• Hit count equals
• Hit count greater than or equal to
• Hit count multiple

After you define a Hit Count Type, you can specify a Hit Count at which the breakpoint executes. This is especially useful when you want to skip some iterations and break at some specific iterations.

How to set breakpoints?

In SSIS designer, navigate to the control flow panel.  Right-click the object where you want to set the breakpoint and then click the Edit Breakpoints option. You will see a Set Breakpoints window popup just like the picture shown above.

Next, select break conditions you like to have. Here you can combine multiple break conditions. For example, you can let it break at both OnPreExecute and OnPostExecute events so that you can examine the changes on variables. The default Hit Count Type is grayed out when the related break condition is unchecked. Once a break condition is selected, you can go further to define Hit Count Type and Hit Count. Below is a breakpoint set at a loop when its loop iteration is equal or larger than 2.

After you close the Set Breakpoints window, you will notice a red dot appears on the object with breakpoints.

Furthermore, setting breakpoints in SSIS Script tasks is a little different from the way shown above. If you would like to know more, please stayed tuned.

How to modify breakpoints?

You can modify the breakpoint in the same way you set breakpoints. Right-click the object and then click the Edit Breakpoints option.

Now you have a powerful tool to help your troubleshooting effectively. With breakpoints, you can step through your ETL package to keep track of your variables and status of packages.