3.1 KiB

scorecard.py

This is an internal script in tests/http/scorecard.py used for testing curl's performance in a set of cases. These are for exercising parts of curl/libcurl in a reproducible fashion to judge improvements or detect regressions. They are not intended to represent real world scenarios as such.

This script is not part of any official interface and we may change it in the future according to the project's needs.

setup

When you are able to run curl's pytest suite, scorecard should work for you as well. They start a local Apache httpd or Caddy server and invoke the locally build src/curl (by default).

invocation

A typical invocation for measuring performance of HTTP/2 downloads would be:

curl> python3 tests/http/scorecard.py -d h2

and this prints a table with the results. The last argument is the protocol to test and it can be h1, h2 or h3. You can add --json to get results in JSON instead of text.

Help for all command line options are available via:

curl> python3 tests/http/scorecard.py -h

scenarios

Apart from -d/--downloads there is -u/--uploads and -r/--requests. These are run with a variation of resource sizes and parallelism by default. You can specify these in some way if you are just interested in a particular case.

For example, to run downloads of a 1 MB resource only, 100 times with at max 6 parallel transfers, use:

curl> python3 tests/http/scorecard.py -d --download-sizes=1mb --download-count=100 --download-parallel=6 h2

Similar options are available for uploads and requests scenarios.

sockd

If you have configured curl with --with-test-danted=<danted-path> for a dante-server installed on your system, you can provide the scorecard with arguments --socks4 or --socks5 to test performance with a SOCKS proxy involved. (Note: this does not work for HTTP/3)

flame graphs

With the excellent Flame Graph by Brendan Gregg, scorecard can turn perf/dtrace samples into an interactive SVG. Either clone the Flamegraph repository next to your curl project or set the environment variable FLAMEGRAPH to the location of your clone. Then run scorecard with the --flame option, like

curl> FLAMEGRAPH=/Users/sei/projects/FlameGraph python3 tests/http/scorecard.py \
   -r --request-count=50000 --request-parallels=100 --samples=1 --flame h2

and the SVG of the run is in tests/http/gen/curl/curl.flamegraph.svg. You can open that in Firefox and zoom in/out of stacks of interest.

The flame graph is about the last run of curl. That is why you should add scorecard arguments that restrict measurements to a single run.

Measures/Privileges

The --flame option uses perf on linux and dtrace on macOS. Since both tools require special privileges, they are run via the sudo command by scorecard. This means you need to issue a sudo recently enough before running scorecard, so no new password check is needed.

There is no support right now for measurements on other platforms.