So far, we’ve been looking at alerts and log messages from system software. Now it’s time to look at how to get error information from your applications. That’s where the Cloud Error Reporting service comes in. To show you how this works, I’m going to install Google’s Hello World application in App Engine and then get it to generate an error.

Normally, you’d use your own workstation for the development environment, but to simplify this demo, I’m going to use Cloud Shell. The nice thing about Cloud Shell is that it already has all of the packages installed that you need. When you do want to write and test Java code on your own workstation, remember that you need to install the Google Cloud SDK, the Java SE 11 Development Kit, Git, and Maven 3.5 or greater on your system.

First, open Cloud Shell. Next, get a copy of the Hello World application with this “git clone” command. Then go into the directory where the app is.

Now use the local development server to make sure the app works. To see if it’s working, click the “Web Preview” icon, and select “Preview on port 8080”. You should see a “Hello world!” message. OK, it’s working, so let’s stop the development server and upload the application to App Engine. You can stop the development server with a Ctrl-C.

Now use the “gcloud app deploy” command to upload it to App Engine. If you’re doing this yourself, then it may look slightly different than mine because I’ve already configured App Engine. If this is your first time deploying to App Engine, then it will likely ask you to choose a region. OK, it’s done deploying.

There are a couple of ways to test it. If you’re not using Cloud Shell, then you could do a “gcloud app browse”, which is pretty handy. Since we are using Cloud Shell, we’ll have to go to this URL. There’s “Hello World!” again.

Now, in order to see an error on the Error Reporting page, we need to generate an error. Let’s edit the code and mess something up. I’m going to add a line that I know will cause a problem and then save the file. This’ll throw an exception because you can’t divide a number by zero.

Now run “gcloud app deploy” again. Let’s see if Error Reporting picked it up. The Google Cloud Console shows errors on the main dashboard, so you don’t have to go to the Error Reporting page to see them. There it is. If you click on the error, you’ll see more details, including a stack trace that shows you where the error occurred. If you want to be notified whenever an error occurs, go to the main Error Reporting page, and click the “Configure notifications” button. You can select any of the notification channels that you’ve already set up through the Cloud Monitoring service, or you can create a new one. 

Alright, that’s it for error reporting.