Linux cpu stress test script how to#
Linux cpu stress test script generator#
Linux cpu stress test script full#
Linux cpu stress test script code#

Consider minimizing the usage of custom metrics. Similar to checks, values for custom metrics (Trend, Counter, Gauge and Rate) are recorded separately. If you are using many checks and groups, you may consider removing them to boost performance. K6 records the result of every individual check and group separately.

Linux cpu stress test script code#

You can consider optimizing the code of the load test itself. If everything else has failed and you are trying to squeeze more performance out of the hardware, Often performance tests are written with a 'happy path' in mind.įor example, a 'happy path' check like the one below is something that we see in k6 often.Ĭopy Remove unnecessary checks, groups and custom metrics When running large stress tests, your script can't assume anything about the HTTP response. General advice Make your test code resilient Tests that are using file uploads can consume tens of megabytes per VU. Run the test on your development machine with 100VUs and multiply the consumed memory by the target number of VUs.

To estimate the memory requirement of your test, Memory consumption heavily depends on your test scenarios. K6 likes memory, but it isn't as greedy as other load testing tools. This may cause the result metrics to have a much larger response time than in reality. If k6 uses 100% to generate load, it won't have enough CPU to measure the responses correctly. We recommend that you size the machine to have at least 20% idle cycles (up to 80% used by k6, 20% idle). Regardless of the test file, you can assume that large tests require a significant amount of CPU power. The amount of CPU you need depends on your test files (sometimes called test script). It will effectively use all available CPU cores. Unlike many other load testing tools, k6 is heavily multi-threaded. Consider upgrading to a different EC2 instance. If the traffic is constant at 1Gbit/s, your test is probably limited by the network card. When running the test, you can use iftop in the terminal to view in real-time the amount of network traffic generated.

Many AWS EC2 machines come with 1Gbit/s connection which may limit the amount of load k6 can generate. Network throughput of the machine is an important consideration when running large tests.

Linux cpu stress test script how to#

To apply these changes, you can either paste these commands as a root user before running a k6 test or change the configuration files in your operating system.įor detailed information about these settings, the macOS instructions, and how to make them permanent, check out our 'Fine-tuning OS' article. These commands enable reusing network connections, increase the limit of network connections, and range of local ports.

Linux cpu stress test script full#

The following OS changes allow k6 to use the full network capacity of the machine for maximum performance. Unless you need more than 100,000-300,000 requests per second (6-12M requests per minute), a single instance of k6 will likely be sufficient for your needs.īelow we will explore what hardware and considerations are needed for generating different levels of load. This number of VUs can generate upwards of 300,000 requests per second (RPS).

Linux cpu stress test script generator#

A single k6 process will efficiently use all CPU cores on a load generator machine.Ī single instance of k6 is often enough to generate load of 30,000-40,000 simultaneous users (VUs). K6 is different from many other load testing tools in the way it handles hardware resources. The common misconception of many load testers is that distributed execution (ability to launch a load test on multiple machines) is required to generate large load.

This document explains how to launch a large-scale k6 test on a single machine without the need for distributed execution.