[Findit] Added algorithm to analysis

appengine/findit/waterfall/flake/recursive_flake_pipeline.py

 # Copyright 2016 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.
 
+import copy
 from datetime import datetime
 
 from common import appengine_util
 from common import constants
 from common.pipeline_wrapper import BasePipeline
 
 from model import analysis_status
 from model.flake.master_flake_analysis import MasterFlakeAnalysis
+from model.flake.flake_swarming_task import FlakeSwarmingTask
 from waterfall.trigger_flake_swarming_task_pipeline import (
     TriggerFlakeSwarmingTaskPipeline)
 from waterfall.process_flake_swarming_task_result_pipeline import (
     ProcessFlakeSwarmingTaskResultPipeline)
 
+# TODO(lijeffrey): Move to config.
+LOWER_FLAKE_THRESHOLD = .02
+UPPER_FLAKE_THRESHOLD = .98
+MAX_FLAKE_IN_A_ROW = 4
+MAX_STABLE_IN_A_ROW = 4
+
 
 class RecursiveFlakePipeline(BasePipeline):
-
   # Arguments number differs from overridden method - pylint: disable=W0221
   def run(self, master_name, builder_name, run_build_number, step_name,
-          test_name, master_build_number, queue_name=constants.DEFAULT_QUEUE):
+          test_name, master_build_number, flakiness_algorithm_results_dict,
+          queue_name=constants.DEFAULT_QUEUE):
+    """
+    Args:
+      master_name (str): The master name.
+      builder_name (str): The builder name.
+      run_build_number (int): The build number of the current swarming rerun.
+      step_name (str): The step name.
+      test_name (str): The test name.
+      master_build_number (int): The build number of the Master_Flake_analysis.
+      flakiness_algorithm_results_dict (dict): A dictionary used by
+        NextBuildNumberPipeline
+      queue_name (str): Which queue to run on.
+    Returns:
+      A dict of lists for reliable/flaky tests.
+    """
+
     # Call trigger pipeline (flake style).
-    task_id = yield TriggerFlakeSwarmingTaskPipeline(master_name, builder_name,
-                          run_build_number, step_name, [test_name])
+    task_id = yield TriggerFlakeSwarmingTaskPipeline(
+        master_name, builder_name, run_build_number, step_name, [test_name])
     # Pass the trigger pipeline into a process pipeline.
     test_result_future = yield ProcessFlakeSwarmingTaskResultPipeline(
         master_name, builder_name, run_build_number,
         step_name, task_id, master_build_number, test_name)
     yield NextBuildNumberPipeline(
-        master_name, builder_name, master_build_number,
-        step_name, test_name, test_result_future, queue_name)
+        master_name, builder_name, master_build_number, run_build_number,
+        step_name, test_name, test_result_future, queue_name,
+        flakiness_algorithm_results_dict)
+
+
+def get_next_run(master, flakiness_algorithm_results_dict):
+    # A description of this algorithm can be found at:
+    # https://docs.google.com/document/d/1wPYFZ5OT998Yn7O8wGDOhgfcQ98mknoX13AesJaS6ig/edit
+    # Get the last result.
+    last_result = master.success_rates[-1]
+    cur_run = min(master.build_numbers)
+    if (last_result < LOWER_FLAKE_THRESHOLD or
+        last_result > UPPER_FLAKE_THRESHOLD): # Stable result.
+      flakiness_algorithm_results_dict['stable_in_a_row'] += 1
+      if (flakiness_algorithm_results_dict['stable_in_a_row'] >
+          MAX_STABLE_IN_A_ROW): #Identified a stable region.
+        flakiness_algorithm_results_dict['stabled_out'] = True
+      if (flakiness_algorithm_results_dict['stabled_out'] and
+          not flakiness_algorithm_results_dict['flaked_out']):
+        # Identified a candidate for the upper boundary.
+        # Earliest stable point to the right of a flaky region.
+        flakiness_algorithm_results_dict['upper_boundary'] = cur_run
+        flakiness_algorithm_results_dict['lower_boundary'] = None
+      elif (flakiness_algorithm_results_dict['flaked_out'] and
+            not flakiness_algorithm_results_dict['stabled_out'] and
+            not flakiness_algorithm_results_dict['lower_boundary']):
+        # Identified a candidate for the lower boundary.
+        # Latest stable point to the left of a flaky region.
+        flakiness_algorithm_results_dict['lower_boundary'] = cur_run
+        flakiness_algorithm_results_dict['lower_boundary_result'] = 'STABLE'
+      flakiness_algorithm_results_dict['flakes_in_a_row'] = 0
+      step_size = flakiness_algorithm_results_dict['stable_in_a_row'] + 1
+    else: # Flaky result.
+      flakiness_algorithm_results_dict['flakes_in_a_row'] += 1
+      if (flakiness_algorithm_results_dict['flakes_in_a_row'] >
+          MAX_FLAKE_IN_A_ROW): #Identified a flaky region.
+        flakiness_algorithm_results_dict['flaked_out'] = True
+      if (flakiness_algorithm_results_dict['flaked_out'] and
+          not flakiness_algorithm_results_dict['stabled_out']):
+        # Identified a candidate for the upper boundary.
+        # Earliest flaky point to the right of a stable region.
+        flakiness_algorithm_results_dict['upper_boundary'] = cur_run
+        flakiness_algorithm_results_dict['lower_boundary'] = None
+      elif (flakiness_algorithm_results_dict['stabled_out'] and
+            not flakiness_algorithm_results_dict['flaked_out'] and
+            not flakiness_algorithm_results_dict['lower_boundary']):
+        # Identified a candidate for the lower boundary.
+        # Latest flaky point to the left of a stable region.
+        flakiness_algorithm_results_dict['lower_boundary'] = cur_run
+        flakiness_algorithm_results_dict['lower_boundary_result'] = 'FLAKE'
+      flakiness_algorithm_results_dict['stable_in_a_row'] = 0
+      step_size = flakiness_algorithm_results_dict['flakes_in_a_row'] + 1
+    next_run = cur_run - step_size
+    return next_run
+
+
+def sequential_next_run(master, flakiness_algorithm_results_dict):
+  last_result = master.success_rates[-1]
+  last_result_status = 'FLAKE'
+  if (last_result < LOWER_FLAKE_THRESHOLD or
+      last_result > UPPER_FLAKE_THRESHOLD):
+    last_result_status = 'STABLE'
+  if flakiness_algorithm_results_dict['sequential_run_index'] > 0:
+    if (last_result_status !=
+        flakiness_algorithm_results_dict['lower_boundary_result']):
+      master.suspected_flake_build_number = (
+          flakiness_algorithm_results_dict['lower_boundary'] +
+          flakiness_algorithm_results_dict['sequential_run_index'])
+      master.put()
+      return 0
+  flakiness_algorithm_results_dict['sequential_run_index'] += 1
+  return (flakiness_algorithm_results_dict['lower_boundary'] +
+          flakiness_algorithm_results_dict['sequential_run_index'])
 
 class NextBuildNumberPipeline(BasePipeline):
+
   # Arguments number differs from overridden method - pylint: disable=W0221
   # Unused argument - pylint: disable=W0613
-  def run(self, master_name, builder_name, master_build_number, step_name,
-          test_name, test_result_future, queue_name):
+  def run(self, master_name, builder_name, master_build_number,
+          run_build_number, step_name, test_name, test_result_future,
+          queue_name, flakiness_algorithm_results_dict):
+
+
     # Get MasterFlakeAnalysis success list corresponding to parameters.
     master = MasterFlakeAnalysis.Get(master_name, builder_name,
                                      master_build_number, step_name, test_name)
+    # Don't call another pipeline if we fail.
+    flake_swarming_task = FlakeSwarmingTask.Get(
+        master_name, builder_name, run_build_number, step_name, test_name)
+
+    # TODO(stgao): Handle case where test doesn't exist.
+    if flake_swarming_task.status == analysis_status.ERROR:
+      master.status = analysis_status.ERROR
+      master.put()
+      return
+
     # Figure out what build_number we should call, if any
-    # This is a placeholder for testing:
-    next_run = False
-    if len(master.build_numbers) < 10:
-      # TODO(caiw): Develop algorithm to optimize this.
-      next_run = min(master.build_numbers) - 10
+    if (flakiness_algorithm_results_dict['stabled_out'] and
+        flakiness_algorithm_results_dict['flaked_out']):
+      next_run = sequential_next_run(master, flakiness_algorithm_results_dict)
+    else:
+      next_run = get_next_run(master, flakiness_algorithm_results_dict)
+
+    if (next_run < flakiness_algorithm_results_dict['last_build_number']):
+      next_run = 0
+
     if next_run:
       pipeline_job = RecursiveFlakePipeline(
           master_name, builder_name, next_run, step_name, test_name,
-          master_build_number)
-      #pylint: disable=W0201
+          master_build_number,
+          flakiness_algorithm_results_dict=flakiness_algorithm_results_dict)
+      # pylint: disable=W0201
       pipeline_job.target = appengine_util.GetTargetNameForModule(
           constants.WATERFALL_BACKEND)
       pipeline_job.start(queue_name=queue_name)
+    else:
+      master.status = analysis_status.COMPLETED
+      master.put()