[ovs-discuss] Instrumenting OVN

[Ryan Moats]

As I mentioned at today's IRC meeting - we have a need to include measuring
the performance of the OVN control channel under scale as part of our CI/CD
test suite, which is driving us to examine the feasibility of some sort of
lightweight instrumentation of ovsdb-server, ovn-controller, and
ovn-northd.
While I'm familiar with the counters that are dumped during an excessive
poll
cycle, those don't entirely meet our needs, as I am looking for something
that allows for the amount of clock time spent in each method as our
starting point.

The reason for the "lightweight" adjective above is that we are looking to
run the same code base in both CI/CD and production, and that means
attaching
a profiler to the code base is contra-indicated.  My initial thought is to
create a new general arg (--profile) that sets a boolean (for example
is_profiling), then define a macro like the following:

#define INSTRUMENT(x)  (if (is_profiling) { VLOG_DEBUG(x); })

and then decorating methods with INSTRUMENT at its start and exit.

But, this is an awful lot of decorating and visual noise and so before
pushing
a large patch series, I wanted to throw the idea on the table and let
people
pick it apart.

Ryan (regXboi)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://openvswitch.org/pipermail/ovs-discuss/attachments/20160519/5d8c5986/attachment-0002.html>