A tracing program for uwsgi+perl environment, using ebpf + perldtrace.
Installation:
sudo yum install plperf
Note: currently only a centos 7 packages is built. A new kernel version is needed (4.19+).
Top commands prints out a snapshot of the perl stack frames of traced uwsgi+perl workers.
An example: sudo plperf -num 3 top
Flame commands generates a file that can be pased by flamegraph.pl to generates a flame graph of the traced workers.
Usage example:
sudo timeout 10 plperf -debug -output app.txt -num 1 -ratio 100 flame
wget https://raw.githubusercontent.com/brendangregg/FlameGraph/master/flamegraph.pl
chmod +x flamegraph.pl
./flamegraph.pl app.txt > app.svg
- It might trigger a segmentfault on app, probably due to some of the perl xs modules.
- Sometimes the program might be stuck, you would have to manually kill it. Then a manual cleanup is needed:
bash -c 'echo > /sys/kernel/debug/tracing/uprobe_events'. - The current flame graph implementation is quite expensive to run on boxes like app where each request is running hundreds of thousands perl subroutines.
Linux source code is needed.
TODO