mogasergiu/strace-tt-plots

The script plot.py is run with the following arguments:

./plot.py /path/to/benchmark/results delay_time

where:

• /path/to/benchmark/results path to the file obtained as a result of running strace -tt
• delay_time is the delay time to differentiate between the setup time of the application and the actual benchmarking

Example 1: Obtaining strace -tt output file for default redis-benchmark:

strace -tt redis-server --port 1234 2>>/tmp/redis-benchmark & \
sleep 0.1; \
redis-benchmark -p 1234 && \
kill -9 $(lsof -t -i:1234);

First we attach strace -tt to redis-server and redirect stderr (strace's default output file descriptor) to our desired output file. We insert our delay of 0.1 to make sure redis-server is ready and then we run the benchmark, after which we kill redis-server to make it stop outputting information to our output file.

Then we simply run:

./plot.py /tmp/redis-benchmark 0.1

And the plot is produced.

Example 2: Obtaining strace -tt output file for default nginx:

sudo service nginx start

First we make sure that nginx is started, then we need to find Nginx's master process PID (You can find it through ps aux | grep nginx) and use the additional -f option of strace to also follow whatever nginx may fork.

strace -ftt -p ${NGINX_MASTER_PID} 2>>/tmp/nginx-wrk & \
sudo service nginx reload; \
sleep 0.2; \
wrk -t12 -c400 -d30s http://127.0.0.1:80/index.html && \
sudo pkill nginx

Then we reload the service to make sure that we strace from the very beginning and catch the worker processes. Finally, we run the default benchmark of wrk. Then, for our plot:

sed '/[pid  [0-9]*] //` && ./plot.py /tmp/nginx-wrk 0.2

Due to the -f option, additional string may be appended at the beginning of lines to indicate which child called which syscall - we want to avoid it.