Trace: 

Generator waterfall.extract_signal_pipeline.ExtractSignalPipeline(*({u'build_number': 65057, u'builder_name': u'Win7 Tests (dbg)(1)', u'builds': {u'65055': {u'blame_list': [u'4b99b0f31388e70d24bbdeecfb03df14b601ae04', u'8b5d92a450f48ccb7ea31cb2e88478868959fbea', u'4c... (4525 bytes), **{})#2c2e38cc16f64ed5880d0b524dd76804 raised exception. Exception: Failed to pull stdio of step webkit_layout_tests of master chromium.win (/base/data/home/apps/s~findit-for-me/waterfall-backend:13177-ba5a63d.406054574164900450/infra_api_clients/../third_party/pipeline/pipeline.py:2434)
Traceback (most recent call last):
  File "/base/data/home/apps/s~findit-for-me/waterfall-backend:13177-ba5a63d.406054574164900450/infra_api_clients/../third_party/pipeline/pipeline.py", line 2158, in evaluate
    self, pipeline_key, root_pipeline_key, caller_output)
  File "/base/data/home/apps/s~findit-for-me/waterfall-backend:13177-ba5a63d.406054574164900450/infra_api_clients/../third_party/pipeline/pipeline.py", line 1113, in _run_internal
    return self.run(*self.args, **self.kwargs)
  File "/base/data/home/apps/s~findit-for-me/waterfall-backend:13177-ba5a63d.406054574164900450/waterfall/extract_signal_pipeline.py", line 33, in run
    failure_info, self.HTTP_CLIENT)
  File "/base/data/home/apps/s~findit-for-me/waterfall-backend:13177-ba5a63d.406054574164900450/services/test_failure/extract_test_signal.py", line 61, in ExtractSignalsForTestFailure
    (step_name, master_name))
Exception: Failed to pull stdio of step webkit_layout_tests of master chromium.win

Appears we're failing to load a proto in logdog util

https://pantheon.corp.google.com/debug?repo=appengine:%3Fservice%3Dwaterfall-backend%26version%3D13177-ba5a63d&fp=%2Finfra_api_clients%2Flogdog_util.py&fl=139&lpopen=true&lpeid=5a29e416000ed172c36c616c:5&lpet=1512694805699&lpee=true&dlv=4&project=findit-for-me&app=GAE:waterfall-backend@13177-ba5a63d&bp=55fc9cbd49e6b-858e-bfa75

Where I got while debugging:

https://pantheon.corp.google.com/debug?repo=appengine:%3Fservice%3Dwaterfall-backend%26version%3D13177-ba5a63d&fp=%2Finfra_api_clients%2Flogdog_util.py&fl=137&lpeid=5a29e416000ed172c36c616c:5&lpet=1512694805699&lpee=true&dlv=4&project=findit-for-me&app=GAE:waterfall-backend@13177-ba5a63d&bp=55fc9d81d43fd-c615-3801b&cs=0

This only impacts reliable test failure analysis for telemetry test. Chan could investigate and fix later when she is back.

Add this as an effort to stabilize Findit.

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/4a1458ab8aeae88fb79279c594083c5bac28b829

commit 4a1458ab8aeae88fb79279c594083c5bac28b829
Author: Chan <chanli@chromium.org>
Date: Tue Jun 12 20:57:39 2018

[Findit] Logdog: Use Get endpoint to get annotations if Tail returns a partial data.

For example: https://luci-logdog.appspot.com/rpcexplorer/services/logdog.Logs/Tail?request={%20%20%20%20%22project%22:%20%22chromium%22,%20%20%20%20%22path%22:%20%22bb/chromium.win/Win7_Tests__1_/80175/+/recipes/annotations%22} For these cases, Tail endpoint gives a partial data so Findit will fail to pull logs. In this case use Get endpoint to get the full data.

Bug:793143
Change-Id: I983350479f6b4252eece76c3ca06c60834e10b3a
Reviewed-on: https://chromium-review.googlesource.com/1079965
Commit-Queue: Chan Li <chanli@chromium.org>
Reviewed-by: Shuotao Gao <stgao@chromium.org>

[modify] https://crrev.com/4a1458ab8aeae88fb79279c594083c5bac28b829/appengine/findit/infra_api_clients/logdog_util.py
[modify] https://crrev.com/4a1458ab8aeae88fb79279c594083c5bac28b829/appengine/findit/infra_api_clients/test/logdog_util_test.py

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/32db1ad8f9584af693e094727e34d2c6538ddd4e

commit 32db1ad8f9584af693e094727e34d2c6538ddd4e
Author: Chan <chanli@chromium.org>
Date: Tue Jul 17 22:41:47 2018

[Findit] Logging error when failed to get log of a step instead of raising exception.

Many Findit pipelines are aborted because Findit raises an exception when failed to get step log. In this case, although Findit will not have heuristic results bacause of lacking of signals, pipeline should continue with try job if possible. So log an error instead.

Bug:793143
Change-Id: I7ec3de25c3662739367fba412a27f8038c7ee74d
Reviewed-on: https://chromium-review.googlesource.com/1132489
Reviewed-by: Roberto Carrillo <robertocn@chromium.org>
Commit-Queue: Chan Li <chanli@chromium.org>

[modify] https://crrev.com/32db1ad8f9584af693e094727e34d2c6538ddd4e/appengine/findit/services/compile_failure/compile_failure_analysis.py
[modify] https://crrev.com/32db1ad8f9584af693e094727e34d2c6538ddd4e/appengine/findit/services/extract_signal.py
[modify] https://crrev.com/32db1ad8f9584af693e094727e34d2c6538ddd4e/appengine/findit/services/compile_failure/extract_compile_signal.py
[modify] https://crrev.com/32db1ad8f9584af693e094727e34d2c6538ddd4e/appengine/findit/services/test_failure/test_failure_analysis.py
[modify] https://crrev.com/32db1ad8f9584af693e094727e34d2c6538ddd4e/appengine/findit/services/test_failure/extract_test_signal.py
[modify] https://crrev.com/32db1ad8f9584af693e094727e34d2c6538ddd4e/appengine/findit/services/compile_failure/test/compile_failure_analysis_test.py
[modify] https://crrev.com/32db1ad8f9584af693e094727e34d2c6538ddd4e/appengine/findit/services/test_failure/test/extract_test_signal_test.py
[modify] https://crrev.com/32db1ad8f9584af693e094727e34d2c6538ddd4e/appengine/findit/services/compile_failure/test/extract_compile_signal_test.py
[modify] https://crrev.com/32db1ad8f9584af693e094727e34d2c6538ddd4e/appengine/findit/services/test_failure/test/test_failure_analysis_test.py