Tendrl profiling

Pre-requisites for enabling Tendrl profiler on a storage node:

• yum install python-devel python-pip
• yum group install "Development Tools"
• pip install GreenletProfiler

About Tendrl profiler:

• Tendrl comes with an internal per service profiler which collects function call statistics (example below)
• Enable profiling for a service by adding with_internal_profiler: True to the service's local config file.

Eg: to enable profiling for tendrl-node-agent

• edit /etc/tendrl/node-agent/node-agent.conf.yaml and add flag with_internal_profiler: True
• restart tendrl-node-agent service systemctl restart tendrl-node-agent
• To gather profiling stats, stop the service after some amount of time systemctl stop tendrl-node-agent
• Function Profiling data in formats (pstat, callgrind, ystat) will be saved at /var/lib/tendrl/profiling/node_agent/last_run_func_stat.pstat
• Output https://gist.github.com/r0h4n/b8905c83789d40b434414957019d247d

Note: profiling is available for all tendrl services except the tendrl-api, the profiling output can be visualized via https://github.com/ymichael/cprofilev (for *.pstat) and via http://valgrind.org/docs/manual/cl-manual.html (for *.callgrind)