Site & API Monitoring

Even if you’ve load tested your site and have a high degree of confidence in its performance and scalability, it could still go down due to human error or something out of your control. Even if it doesn’t crash, someone on your team might push a breaking change that introduces a bug.

When that happens, you’ll want to be the first to know about it!

The word monitoring can mean a lot of things, but we’re actually talking about synthetic monitoring, which means generating traffic to simulate real user traffic hitting your site and evaluating the responses to make sure it’s all working right.

Loadster makes it pretty easy to accomplish this, by running your Loadster scripts on a schedule (with a single v-user) and notifying you of any errors. If you’ve already created load test scripts simulating realistic user behavior, you can use these very same scripts for monitoring!

What kind of things can Loadster monitor?

Loadster’s monitors do a lot more than just check if the site is up and accepting requests. They also evaluate its functionality and performance with transactional flows.

In fact, anything you can do in a Loadster script, you can do in a monitor. For example:

  • Test your login sequence with a different username and password each time, pulling from a dataset
  • Test your registration flow with randomly generated data
  • Monitor an ecommerce site by shopping for items and adding them to the shopping cart
  • Make a sequence of correlated requests against your API, using the output from one in the subsequent request

Continuously monitoring your site’s functionality and performance (as well as uptime) gives you a big head start when it comes to quickly detecting and fixing all sorts of problems!

Cool! So how do I set up a monitor?

After you’ve created at least one Loadster script, the new Monitors section will appear on your dashboard.


Click Add to add a monitor.

Create monitor
Create monitor

Select the script you’d like to use for monitoring, the monitoring frequency, and one or more regions where you’d like the monitoring traffic to originate from.

When you create the monitor, it will typically start running the first cycle within seconds, and subsequent cycles according to the frequency you specified.

Each monitor will show a graph with a rolling history of cycles. Each cycle has a pass/fail status (indicated by the color of the cycle) and an average response time (indicated by the vertical position of the data point).

Select a cycle to see detailed Logs and drill down on Results from that cycle, just like you can when playing scripts in the script editor. This should make it pretty easy to figure out what went wrong when one of your monitors fails!

Monitor logs
Monitor logs

After the monitors have been running for a while, you can quickly eyeball how they’re all doing on your dashboard.

Monitor status
Monitor status

No need to watch the dashboard obsessively – you’ll also receive email notifications if any of your monitors fail.

How does Loadster determine if a monitoring cycle is a pass or fail?

Monitor cycles will be deemed a FAIL if any step in the script results in an error. This can be any type of error:

  • Socket or network error (such as a connection timeout or failure to connect)
  • HTTP error (a response status code greater than or equal to 400)
  • Validation error (one of your validation rules failed)
  • Internal error (not very common)

It’s usually a good idea to add your own validation in addition to the default criteria, to make sure the responses look just like you’d expect. This can reduce the chance of false positive outcomes.

If a script runs and no errors are reported, it will be considered a PASS.

Who gets notified when a monitor fails or recovers?

By default, all users on your Loadster team (including yourself) will receive email notifications when a monitor fails, and again when a monitor that was previously failing recovers.

You can change your personal notification preferences on the Account page of your Loadster dashboard. Anyone on your Loadster team can do the same.

What kind of monitoring is included in my Loadster plan?

If you’re on any Unlimited Plan, you can create up to 50 monitors, with each monitor running as frequently as once per minute. On the free plan, you can still create monitors, but it’s limited to 10 monitors with each monitor running just a few times a day.

If you really dig monitoring and want even more monitors, contact for a custom plan!

Alternatively, you might want to check out our monitoring-only product, Speedway, which has a lot in common with Loadster as far as scripting is concerned.