Stress testing with errors
Despite the harshness of tests that push your system beyond its limits, lab testing still misses conditions that will be present in real-life usage. The day your advert goes viral and loading jumps, you will still have all the packet loss, latency, and even the chance of internal failures of a typical day. For a complete test, remember to include these low-level issues in your testing.
As with load testing, to apply controlled errors, you must start with an error-free system (see the Technical requirements section in Chapter 12, Load Testing). To perform any of the tests in this chapter, you need a reliable setup with all the resources and equipment of the live system on controlled networks without packet loss or other issues. From that start point, you can apply loading and degradation combinations. Recall the sources of network degradation from Chapter 7, Testing of Error Cases:
- Packet loss
- Latency
- Jitter
- Re-ordering
- Duplication...
