Reduce load on autotest by cutting number of forks and parsers.

Forking is still required to keep logging and parsing working.  By using a multiprocessing queue instead of a normal queue ServerJob can fork once per test host instead of once per test.

Also make continuous parsing an opt in request instead of a default feature.  Continuous parsing adds a parser per host, and with many concurrent hosts in concurrent tests for concurrent builds this load adds up.  BVT runs take a few minutes and don’t need an instantaneous update in the front end.  But longer running suites will still benefit from being able to give status updates as they run.

Change-Id: I03c898d7aff4eaae44d55c5106f789fc16326783

BUG=None.
TEST=Multi-Machine BVT with and without continuous parsing.

Review URL: http://codereview.chromium.org/6902033
2 files changed