When updating code in Envoy it is often useful to try to reason about the performance impact of a change you are making. It is handy to have a suite of scripts to help measure performance. These scripts should not be used for absolute benchmarking.

When running performance benchmarks, some basic principles can help give the best results:

1. Run performance benchmarks on optimized builds: bazel build -c opt source/exe:envoy-static.
2. Don't let any other software run on the machine at the same time.
3. Make sure the configuration you are testing actually hits the code you are editing.
4. If you are testing code changes, interleave runs between an envoy-static built from master and one built from your branch.

Siege is a github project that efficiently pummels an HTTP 1.1 server with requests and measures overall throughput, error rate, and max latency. It is also available pre-built on Debian and possibly other distros.

You must have python3 and the siege binary installed, either from the distro or by building from https://github.com/JoeDog/siege.

sudo apt-get install siege

cd ../envoy
bazel build -c opt source/exe:envoy-static
mv bazel /tmp/envoy.experimental
git checkout master
bazel build -c opt source/exe:envoy-static
mv bazel /tmp/envoy.clean