Cap the maximum number of flaky tests that we record from a step

appengine/chromium_try_flakes/handlers/flake_issues.py

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Task queue endpoints for creating and updating issues on issue tracker."""
 
 import datetime
 import json
 import logging
 import urllib2
@@ skipping 12 matching lines @@
 from status import build_result, util
 from test_results.util import normalize_test_type, flatten_tests_trie
 
 
 MAX_UPDATED_ISSUES_PER_DAY = 50
 MAX_TIME_DIFFERENCE_SECONDS = 12 * 60 * 60
 MIN_REQUIRED_FLAKY_RUNS = 3
 DAYS_TILL_STALE = 30
 USE_MONORAIL = True
 DAYS_TO_REOPEN_ISSUE = 3
+MAX_INDIVIDUAL_FLAKES_PER_STEP = 50
 FLAKY_RUNS_TEMPLATE = (
     'Detected %(new_flakes_count)d new flakes for test/step "%(name)s". To see '
     'the actual flakes, please visit %(flakes_url)s. This message was posted '
     'automatically by the chromium-try-flakes app. Since flakiness is ongoing, '
     'the issue was moved back into %(queue_name)s (unless already there).')
 SUMMARY_TEMPLATE = '"%(name)s" is flaky'
 DESCRIPTION_TEMPLATE = (
     '%(summary)s.\n\n'
     'This issue was created automatically by the chromium-try-flakes app. '
     'Please find the right owner to fix the respective test/step and assign '
@@ skipping 458 matching lines @@
 
     try:
       result = urlfetch.fetch(url)
 
       if result.status_code >= 200 and result.status_code < 400:
         json_result = json.loads(result.content)
 
         _, failed, _ = cls._flatten_tests(
             json_result.get('tests', {}),
             json_result.get('path_delimiter', '/'))
+        if len(failed) > MAX_INDIVIDUAL_FLAKES_PER_STEP:
+          return [stepname], True
         return failed, False
 
       if result.status_code == 404:
         # This is quite a common case (only some failing steps are actually
         # running tests and reporting results to flakiness dashboard).
         logging.info('Failed to retrieve JSON from %s', url)
       else:
         logging.exception('Failed to retrieve JSON from %s', url)
     except Exception:
       logging.exception('Failed to retrieve or parse JSON from %s', url)
@@ skipping 135 matching lines @@
         return
 
     key = self.request.get('key')
     flake = ndb.Key(urlsafe=key).get()
     flake.issue_id = issue_id
     flake.put()
 
     logging.info('%s updated issue_id for flake %s to %d.', user_email,
                  flake.name, issue_id)
     self.redirect('/all_flake_occurrences?key=%s' % key)