[LLVMdev] Dev Meeting BOF: Performance Tracking

[Renato Golin]

On 2 August 2014 01:24, Yi Kong <kongy.dev at gmail.com> wrote:
> We have this in LNT now which can be activated using `--benchmarking-only`.
> It's about 50% faster than a full run and massively reduces the number of
> false positives.

Excellent! Does that mean I can create another LNT buildbot with an
extra flag and I'll get my benchmarking bot?


> We are now testing PostgreSQL as database backend on the public perf server,
> replacing the SQLite db. Hopefully this can improve the stability and system
> performance.

I believe a real database would make things more stable but I don't
think that the problem is in the DB, only that a better DB will hide
the real problem even deeper.

But I'm also not in the position to offer help debug the thing, so
I'll go with what you guys think is the best.


> Also being discussing is to move the LNT server to a PaaS service, as it has
> higher availability and saves a lot of maintenance work. However this will
> need community to provide or fund the hosting service.

I've been thinking about this for a while and I think the LLVM
Foundation could make this happen across the globe.

If I got it right, part of the foundation's purpose is to make sure we
have a stable, modern and effective infrastructure for building,
testing and benchmarking LLVM, as well as other critical development
tools like bugzilla, phabricator and svn/git repositories. My proposal
is to use the foundation's charitable status to get help from around
the world for redundant services.

I don't know about PostgreSQL, but MySQL has a master/slave setting
that works fantastically well across continents, so that there is only
one master (with switch-over facility in case of failure) and multiple
remote slaves. I believe that services line LNT, bugzilla, phabricator
could highly benefit from this. Other services like git could also
have back-up copies (maybe making an official GitHub repo as a
redundant copy of out oficial repo), and buildbots would be easy to
have at least one slave of the same bot config on each continent, so
that if one fails, another is still up and running. The hardest one to
get that distributed is SVN.

If we could get universities in Europe and Asia, in addition to the
ones in US that host and maintain LLVM tools, we could have a really
reliable infrastructure without raising costs that much. I'd be happy
to pursue this in England (maybe even Brazil) and I believe there are
developers that would be glad to do this across Europe and Asia.

cheers,
--renato