View message data with the Debug view

This page applies to Apigee and Apigee hybrid.

View Apigee Edge documentation.

What you'll learn

In this tutorial, you'll learn to:

• See the response message's headers and body content.
• See error messages.

What you'll need

• Before you begin, you must complete the steps in Overview and prerequisites.
• At least one policy in your proxy.
• curl installed on your machine to make API calls from the command line.

View message data

The Debug view in the Apigee Proxy Editor lets you view headers, variables, objects, and other details such as response time in the API proxy request and response flow. The Debug view also lets you see how a request or response changes as it is processed by an API proxy. For a more detailed description of the debug view, see Using Debug.

In the previous tutorial, you restricted the number of requests with the SpikeArrest policy. This page describes how to use the Debug view to see what happens when that rate is exceeded.

Note: Apigee is introducing a new version of the Proxy Editor, which will make it easier to manage proxies.

The instructions in the first two tabs below explain how to use either the new Proxy Editor or the classic Proxy Editor.

New Proxy Editor

1. On the Develop tab of the API Proxy, edit the Spike Arrest policy's <Rate> to be 1pm again, then Save the proxy. This will allow you to see both successful and failed (over the limit) API calls.
2. In the Proxy Editor, click the Debug tab.
3. Click Start Debug Session.

In the dialog:

1. Select the Environment in which you want to run the debug session.
2. (Optional) From the Filter drop-down list, select a filter to apply to all transactions in the debug session you are creating. The default is None (All transactions), which includes all transactions in the debug data.

   For information on using filters, see Using filters in a debug session. For information about the built-in filters, see Using predefined filters.

3. Click Start.

4. Call the API proxy again using curl (or with the URL in a web browser) several times until you see at least one 200 response and one 429 response in the left-hand pane.

   

   Note: The HTTP status code for exceeding the rate limit is 429 Too many requests.
5. Click the 429 transaction in the left-hand pane. This displays a Gantt chart for the transaction in the right-hand pane.

   

   Note that there is a row for the Spike Arrest policy, which is displayed with an error icon.

6. Click the row labeled Error. This displays the error details to the right of the chart. The picture below shows the Properties section of the error details:

   

You can click the Back and Next buttons below the Gannt chart to move between steps in the flow and see the details of each step.

To download the entire debug session as a single document, click Download Session. A debug session is deleted within 24 hours of the time it is completed, so if you want to view the session after that time, you need to download it before then.

Classic Proxy Editor

1. On the Develop tab of the API proxy, edit the Spike Arrest policy's <Rate> to be 1pm again, then Save the proxy. This will allow you to see both successful and failed (over the limit) API calls.
2. In the Proxy Editor, click the Debug tab.
3. Under Start a debug session, select the environment to which your proxy is deployed.
4. Click Start Debug Session.

5. Call the API proxy again using curl (or with the URL in a web browser) until you see at least one 200 response and one 429 response in the Debug Transactions pane.

   curl -v https://YOUR_ENV_GROUP_HOSTNAME/my-proxy

   where YOUR ENV_GROUP_HOSTNAME is the environment group hostname. See Find the environment group hostname.

   A 200 response and a 429 response are shown below.

   

   Note: The default HTTP status code for exceeding the rate limit is 429 Too many requests.

   If you want the status code to be different (500, for example) for all Spike Arrest policies used in an organization, a property needs to be set on your organization. If you're a Cloud customer, contact Google Cloud Customer Care to set that property.

6. Click the 200 transaction in the left Transactions pane. Its Debug detail is loaded in the main window under Transaction Map, which shows a request/response diagram. The Spike Arrest icon is in the request flow.
7. In the flow diagram, click the circle icon in the response, the furthest one to the right (shown in the following diagram).

   The Phase Details pane shows the data available at that point in the flow. If you scroll through that pane, you'll see the HTTP response headers and body content.

8. Now look at an error in Debug.

   Click the 429 transaction in the Transactions pane. In the main editor window, you see a flow diagram with items in the request only, including a Spike Arrest icon with a red exclamation point indicating an error.

   Click the small tube-shaped error icon to the right of the Spike Arrest icon, and look at the spike arrest violation details in the Phase Details pane.

   

You can click the Back and Next buttons in the flow diagram to move between points in the flow and see the Debug details.

If you want to see the entire Debug session as a single document, download it by clicking Download Debug Session.

For more information, see Using Debug.