What to check when stress testing
As with load testing, you need to constantly check your system during stress tests. First, carefully review your monitoring as described in Chapter 10, Maintainability. Track any errors or alarms generated during your tests and errors in the logs. That should be a given during any testing but is especially true here.
Stress testing is an external pressure you put on your service – an expected problem. As such, even stress testing shouldn’t show any errors. In my experience, that won’t be the case, so one of your first tasks will be to raise those alerts with the development team to either fix or downgrade to a warning.
Recall the list of system metrics from Chapter 12, Load Testing. All those measures are also important when running stress tests:
- CPU:
- High sustained levels
- Spikes of usage
- Disk:
- High usage
- High rates of increase
- Memory:
- High usage
- High rates of increase
- System resources:
- Handles
- Addresses
- Database...
