Check a crashed app for errors by using Error Reporting

Check a crashed app for errors by using Error Reporting

Error Reporting provides a single place to monitor error conditions from all apps and services in a Google Cloud project and from Amazon Elastic Compute Cloud (EC2) applications.

In this guide, we learn how to do the following:

1. Simulate an error from a service in a Google Cloud project.

2. Use Error Reporting to view the error and change the error status so other people on your team know that the issue is being addressed.

3. Set up notifications so you'll know when new types of errors occur.

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To follow step-by-step guidance for this task directly in the Google Cloud console, click Guide me:

Guide me

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Before you begin

Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.

In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

Go to project selector

Make sure that billing is enabled for your Google Cloud project.

In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

Go to project selector

Make sure that billing is enabled for your Google Cloud project.

1. Open a Cloud Shell for your Google Cloud project. While it starts, the message Connecting is displayed.

   Open Cloud Shell.

Simulate an error

1. To generate 11 sample errors, run the following script in Cloud Shell:

     COUNTER=0
     while [  $COUNTER -lt 11 ]; do
         gcloud beta error-reporting events report --service tutorial --service-version v$((COUNTER/10+1)) \
             --message "java.lang.RuntimeException: Error rendering template $COUNTER
               at com.example.TestClass.test(TestClass.java:51)
               at com.example.AnotherClass(AnotherClass.java:25)
               at javax.servlet.http.HttpServlet.service (HttpServlet.java:617)
               at javax.servlet.http.HttpServlet.service (HttpServlet.java:717)"
         if [ $COUNTER -eq 10 ]; then
           echo "All sample errors reported."
         fi
         let COUNTER=COUNTER+1
     done
   

   When the script finishes generating all of the errors, it prints the following line:

   All sample errors reported.

View the errors in Error Reporting

1. In the Google Cloud console, go to the Error Reporting page:

   Go to Error Reporting

   You can also find this page by using the search bar.

   The Error Reporting dashboard displays a summary list of each error found and the number of occurrences of each error. When Auto reload is turned on, Error Reporting automatically reloads the error list every 10 seconds.

   The following screenshot shows a sample error reporting page:

   

2. Click the error name to view the error details page, which contains all of the available information about an error. If Gemini is enabled in the project, then you can use Gemini to get troubleshooting suggestions.

Configure notifications

You can configure Error Reporting to notify you when a new type of error arrives. Notifications aren't sent when there are new occurrences of existing errors:

1. In the Google Cloud console, go to the Error Reporting page:

   Go to Error Reporting

   You can also find this page by using the search bar.

2. To enable email notifications, click More and select Turn on new error notifications for project from the drop-down list.

3. To generate new types of errors, click Activate Cloud Shell and run the following script:

     COUNTER=0
     while [ $COUNTER -lt 3 ]; do
           gcloud beta error-reporting events report --service tutorial --service-version v1 \
               --message "java.lang.ArrayIndexOutOfBoundsException: $COUNTER
                 at com.example.AppController.createUser(AppController.java:42)
                 at com.example.User(User.java:31)
                 at javax.servlet.http.HttpServlet.service (HttpServlet.java:617)
                 at javax.servlet.http.HttpServlet.service (HttpServlet.java:717)"
         if [ $COUNTER -eq 10 ]; then
           echo "All sample errors reported."
         fi
         let COUNTER=COUNTER+1
     done
   

   When the script finishes generating all of the errors, it prints the following line:

   All sample errors reported.

4. Check your email for a message from "Stackdriver Notifications".

Generate error messages from a App Engine app

While the sample messages you generated from the scripts fully simulate error conditions in Error Reporting, if you want to generate errors from a real service running in your Google Cloud project, follow the steps in this section.

Deploy an app

To download and deploy an app to App Engine, do the following:

1. Download and configure the application from the GitHub project python-docs-samples:

   1. Clone the project to your Cloud Shell:

      git clone https://github.com/GoogleCloudPlatform/python-docs-samples
      

      Git returns a message similar to this:

      git clone https://github.com/GoogleCloudPlatform/python-docs-samples
      Cloning into 'python-docs-samples'...
      

   2. Create an isolated Python environment and activate it:

      cd python-docs-samples/appengine/standard_python3/hello_world
      virtualenv env -p python3
      source env/bin/activate
      

   3. Install dependencies:

      pip install -r requirements.txt
      

2. Verify that the application installation and configuration are successful:

   1. Run the application:

      python main.py
      

   2. To view the application on a local web page, click the link displayed in Cloud Shell. The web page displays Hello World!.

   3. To stop your running application, in Cloud Shell enter Ctrl-C.

3. Upload your application to App Engine:

   gcloud app deploy
   

   If prompted for a deployment region, select one near you. Enter Y when asked if you want to continue. After a few moments, the upload is complete.

4. View your application in a browser by running the following command in Cloud Shell:

   gcloud app browse
   

   If the Google Cloud CLI can't find your browser, the previous command displays an error message and a link. Click the displayed link. The message Hello, World! is displayed in the browser.

Generate an error

To create an error that Error Reporting catches and displays, do the following:

1. Edit main.py and change

   return 'Hello World!
   

   to

   return 'Hello World!' + 1000
   

   When executed, this change causes a Python TypeError exception because it is illegal to concatenate a string and an integer.

2. Upload the modified application to App Engine:

   gcloud app deploy
   

3. Return to the browser tab containing the running application, and reload the page. Because of your change, instead of the page displaying Hello, World!, it displays an error message:

   Internal Server Error
   The server encountered an internal error and was unable to complete your
   request. Either the server is overloaded or there is an error in the
   application.
   

   If you don't see this message, wait a minute and reload it again. It might take a few moments before the new version is activated.

View the error in Error Reporting

To view the error, follow the instructions in the previous section View the errors in Error Reporting.

Clean up

To avoid incurring charges to your Google Cloud account for the resources used on this page, follow these steps.

Caution: Deleting a project has the following effects:
• Everything in the project is deleted. If you used an existing project for the tasks in this document, when you delete it, you also delete any other work you've done in the project.
• Custom project IDs are lost. When you created this project, you might have created a custom project ID that you want to use in the future. To preserve the URLs that use the project ID, such as an appspot.com URL, delete selected resources inside the project instead of deleting the whole project.
1. In the Google Cloud console, go to the Manage resources page.

   Go to Manage resources

2. In the project list, select the project that you want to delete, and then click Delete.
3. In the dialog, type the project ID, and then click Shut down to delete the project.

What's next

• Learn more about viewing errors

• Learn more about managing errors