Juan: I highly suspect that this is related to your forwarder refactoring. Can you take a look?

This benchmark does not appear to show on https://test-results.appspot.com/dashboards/flakiness_dashboard.html, any idea why?

Anyway, by log grepping it appears that the error happens flakily about 20% - 25% of the time on recent builds from the bots linked above.

The error indeed is:

    return DoNothingForwarder(local_port, remote_port)
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\forwarders\do_nothing_forwarder.py", line 52, in __init__
    self._WaitForConnectionEstablished()
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\forwarders\do_nothing_forwarder.py", line 65, in _WaitForConnectionEstablished
    raise ConnectionError('Unable to connect to address: %s:%d' % address)
ConnectionError: Unable to connect to address: 127.0.0.1:52313

I can try raising the timeout (e.g. from 10 to 20 secs) to see if that helps.

Alternatively, while doing the refactor I've also wondered whether the DoNothingForwarder should do a connectivity check at all. One could argue that the forwarder should "DoNothing", as the name implies, if the connection to that address later fails at least we would get a more relevant traceback closer to the thing we actually want to connect to.

Any thoughts?

#3: I agree, I am maing a CL in https://chromium-review.googlesource.com/c/catapult/+/911938/1

Somehow I messed up my bug watch setting and didn't receive you comment in #3 until now.

The following revision refers to this bug:
  https://chromium.googlesource.com/catapult/+/9055bd85609b1ed38ccaa536bad152469b8a62d6

commit 9055bd85609b1ed38ccaa536bad152469b8a62d6
Author: Nghia Nguyen <nednguyen@google.com>
Date: Fri Feb 09 20:54:06 2018

Remove connection check in DoNothingForwarder

This check doesn't do thing useful & causing flakiness on Win platform

Bug: chromium:809592 

TBR=perezju@chromium.org

Change-Id: I2cb9ce4bcf8531e536456e06a748926cf9e88bf5
Reviewed-on: https://chromium-review.googlesource.com/911938
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Commit-Queue: Ned Nguyen <nednguyen@google.com>

[modify] https://crrev.com/9055bd85609b1ed38ccaa536bad152469b8a62d6/telemetry/telemetry/internal/forwarders/do_nothing_forwarder_unittest.py
[modify] https://crrev.com/9055bd85609b1ed38ccaa536bad152469b8a62d6/telemetry/telemetry/internal/forwarders/do_nothing_forwarder.py

The win builder is green again! https://ci.chromium.org/buildbot/chromium.perf/Win%207%20Intel%20GPU%20Perf/2014