AWS: Is it possible to monitor an external service?

Question

With CloudWatch you can monitor applications running on AWS. Is it also possible to monitor an external service?

For example, I have a REST API and I want to get notified once that API is not accessible anymore. Does AWS offer you a monitoring tool for that purpose?

Answer 1

Not Cloudwatch just by itself, but you can use a combination of Cloudwatch and Lambdas to do what you're asking. You can use cloudwatch events to run lambdas on a schedule, something like once every 5 mins.

CloudwatchEvents -> HealthCheck Lambda -> Cloudwatch Custom Metrics

Your lambda can then ping the API you're monitoring the health of, and either send its status to cloudwatch as a custom metric; or potentially if your lambda throws an error when the API fails, the lambda error metric which is already in cloudwatch becomes your API failure metric

Once the metric exists in cloudwatch, either as a custom metric or the lambda metric by proxy, you're able to do usual cloudwatch things like alarms and notifications.

Answer 2

Now there is a simple way to monitor external resources - CloudWatch Synthetics. Just create a canary to regularly monitor a website, API or even validate a multi-step UI flow.

Read more in the docs: CloudWatch > Using Synthetic Monitoring

Answer 3

Amazon CloudWatch supports custom metrics generated by your applications and services that you do not run on AWS. In this way, CloudWatch can be an integrated storage and aggregation point, allowing you to monitor all of the metrics that you collect, and track on a single platform.

There might be more than one way to reach your goal by using the AWS CLI, an API/SDK, or the CloudWatch collectd plugin etc. I'd recommend you take a look at these links for more details: link-1, link-2, link-3, link-4