Work with Lightrun Metrics in the VS Code IDE¶

The Lightrun plugin for VSCode currently provides three different metrics action for monitoring the performance of your code and identifying issues:

• Counters - Counts the number of times a specific line of code is reached.

• Tic & Toc - Measures the elapsed time between two selected lines of code within a function.

• Custom Metrics - Create customized metrics, using parameters and simple or complex expressions that return a long int result.

The following subsections describe:

• How to add a metrics action to your running application.
• Configuration option for each metric action.
• Managing a metrics action directly from your VSCode IDE.

Adding Metrics¶

There are two ways to insert a Lightrun metric into your code.

1. From the Agents or Tags tab.
2. From a code line in your VSCode editor.

Agents or Tags tab¶

1. Open the Lightrun Sidebar in your VSCode IDE.
2. Navigate to the Agents or Tags tab and select an agent or tag.
3. Click the Add Action icon on the agent or tag.

4. Select your preferred metric from the menu that appears.

   

Code line method¶

1. Go to the line in your application source code where you'd like to insert the metric. Make sure to use the source code version currently deployed to your remote app (where the agent is attached).
2. Right-click to open the VSCode context menu.
   
3. From the VSCode context menu, click Lightrun....
   The VSCode Command Palette opens with a list of Lightrun plugin options.
   
4. Select your preferred metric in the VSCode Command Palette.

Configuring Metrics¶

Counter¶

A Lightrun Counter counts the number of times a specified line of code is reached and outputs the data periodically to the configured action target.

With a Lightrun Counter output, you can obtain a deeper insight into the state of your application's code, at any level of detail, from expressions and method calls to individual variables.

The Insert a Counter form should appear similar to the following image.

The following table describes the available configuration options.

Tic & Toc¶

The Tic & Toc metric measures the elapsed time of code execution between two specified lines, Tic (start line) and Toc (end line), in the same code block.

The Insert a Tic & Toc form should appear similar to the following image.

The following table describes the available configuration options.

Custom Metric¶

You can insert your own customized metrics expressions that evaluate to a long integer result.

The Insert a Custom Metric form should appear similar to the following image.

The following table describes the available configuration options.

Managing metrics¶

Once a Lightrun metric has been inserted into your application,

1. A new metric action will appear under the selected source (agent or tag) in the Lightrun sidebar.
2. A metric icon will appear next to the selected code line. See the table below for each metric and their icons.

Metric	Icon
Counter
Tic & Toc
Custom Metric

You can view, disable, or delete a metric directly in your VSCode IDE.

To view a metric action configuration¶

1. Click the menu icon ... next to the relevant metric in the Lightrun sidebar to open the ACTION OPTIONS menu.

   

2. Select Details to open the metric details panel. The metric details panel should appear similar to the following image. (details for the Tic & Toc action is shown below).
   

To disable a metric action¶

1. Hover your cursor over the relevant metric in the Lightrun sidebar.
   A toggle switch should appear.
   
2. Click the toggle switch from blue (on) to grey (off).
3. To resume logging, click the toggle back to blue.

Duplicating a metric action¶

1. Hover your cursor over the relevant metric in the Lightrun sidebar.

2. Right-click and select Duplicate.

   

3. Go to the selected destination and right-click and select Duplicate.

Deleting a metric action¶

1. Click the menu icon ... next to the relevant metric in the Lightrun sidebar to open the ACTION OPTIONS menu.

   

2. Select Delete to delete the metric action.

Understanding metrics data¶

Counter¶

An example Lightrun Counter output is shown in the code sample below:

CounterData Log{counterId='9b1e6b80-b5ec-42dd-b411-28bbb3e44059', name=counter1::*, count=751, m1_rate=49.51307448246653, m5_rate=53.94779140968095, m15_rate=54.77571845490024, mean_rate=35.71689054874403}

The following table describes the data present in a Counter output.

Time measurements¶

An example Lightrun Time measurement output is shown in the code sample below:

TicToc Log {TicTocId='670a505f-33c1-4c8c-846b-57afaa9a236c', name='MeasurementName', count='17', max='5', min='0', mean='0.46618461992518356', stddev='1.1864864756822397'}

The following table describes the data present in a Time measurement output.