The autocannon tool allocates a pool of connections (as per the -c 100 setting), issuing a request on each socket immediately after the previous has completed.
This technique emulates a steady concurrency level while driving the target to maximise resource utilization without over saturating.
Apache Benchmark
Apache Benchmark (ab) is another tool for load testing HTTP servers. However, ab adopts a different paradigm and executes a specific amount of requests per second, regardless of whether prior requests have completed. Apache Benchmark can be used to saturate an HTTP endpoint to the point where some requests start to timeout, this can be useful for finding the saturation limit of a server, but can also be problematic when it comes to troubleshooting a problem.
Apache Benchmark (ab) is another tool for load testing HTTP servers. However, ab adopts a different paradigm and executes a specific amount of requests per second, regardless of whether prior requests have completed. Apache Benchmark can be used to saturate an HTTP endpoint to the point where some requests start to timeout, this can be useful for finding the saturation limit of a server, but can also be problematic when it comes to troubleshooting a problem.