Make unittest_utils log its perf data to a database, optionally.
authorScott <[email protected]>
Mon, 17 Jan 2022 23:54:14 +0000 (15:54 -0800)
committerScott <[email protected]>
Mon, 17 Jan 2022 23:54:14 +0000 (15:54 -0800)
unittest_utils.py

index 8c9a1202f99d46708b8abfd083fc3f57256fcacc..584eb3ce002d3fed3363223cbe4a3cf9059313a6 100644 (file)
@@ -7,20 +7,26 @@
    caveat emptor.
 """
 
+from abc import ABC, abstractmethod
 import contextlib
 import functools
 import inspect
 import logging
+import os
 import pickle
 import random
 import statistics
 import time
 import tempfile
-from typing import Callable
+from typing import Callable, Dict, List
 import unittest
+import warnings
 
 import bootstrap
 import config
+import scott_secrets
+
+import sqlalchemy as sa
 
 
 logger = logging.getLogger(__name__)
@@ -36,7 +42,7 @@ cfg.add_argument(
 cfg.add_argument(
     '--unittests_num_perf_samples',
     type=int,
-    default=20,
+    default=50,
     help='The count of perf timing samples we need to see before blocking slow runs on perf grounds'
 )
 cfg.add_argument(
@@ -46,13 +52,120 @@ cfg.add_argument(
     default=None,
     help='The identifier (i.e. file!test_fixture) for which we should drop all perf data'
 )
-
+cfg.add_argument(
+    '--unittests_persistance_strategy',
+    choices=['FILE', 'DATABASE'],
+    default='DATABASE',
+    help='Should we persist perf data in a file or db?'
+)
+cfg.add_argument(
+    '--unittests_perfdb_filename',
+    type=str,
+    metavar='FILENAME',
+    default=f'{os.environ["HOME"]}/.python_unittest_performance_db',
+    help='File in which to store perf data (iff --unittests_persistance_strategy is FILE)'
+)
+cfg.add_argument(
+    '--unittests_perfdb_spec',
+    type=str,
+    metavar='DBSPEC',
+    default='mariadb+pymysql://python_unittest:<PASSWORD>@db.house:3306/python_unittest_performance',
+    help='Db connection spec for perf data (iff --unittest_persistance_strategy is DATABASE)'
+)
 
 # >>> This is the hacky business, FYI. <<<
 unittest.main = bootstrap.initialize(unittest.main)
 
 
-_db = '/home/scott/.python_unittest_performance_db'
+class PerfRegressionDataPersister(ABC):
+    def __init__(self):
+        pass
+
+    @abstractmethod
+    def load_performance_data(self) -> Dict[str, List[float]]:
+        pass
+
+    @abstractmethod
+    def save_performance_data(self, method_id: str, data: Dict[str, List[float]]):
+        pass
+
+    @abstractmethod
+    def delete_performance_data(self, method_id: str):
+        pass
+
+
+class FileBasedPerfRegressionDataPersister(PerfRegressionDataPersister):
+    def __init__(self, filename: str):
+        self.filename = filename
+        self.traces_to_delete = []
+
+    def load_performance_data(self, method_id: str) -> Dict[str, List[float]]:
+        with open(self.filename, 'rb') as f:
+            return pickle.load(f)
+
+    def save_performance_data(self, method_id: str, data: Dict[str, List[float]]):
+        for trace in self.traces_to_delete:
+            if trace in data:
+                data[trace] = []
+
+        with open(self.filename, 'wb') as f:
+            pickle.dump(data, f, pickle.HIGHEST_PROTOCOL)
+
+    def delete_performance_data(self, method_id: str):
+        self.traces_to_delete.append(method_id)
+
+
+class DatabasePerfRegressionDataPersister(PerfRegressionDataPersister):
+    def __init__(self, dbspec: str):
+        self.dbspec = dbspec
+        self.engine = sa.create_engine(self.dbspec)
+        self.conn = self.engine.connect()
+
+    def load_performance_data(self, method_id: str) -> Dict[str, List[float]]:
+        results = self.conn.execute(
+            sa.text(
+                f'SELECT * FROM runtimes_by_function WHERE function = "{method_id}";'
+            )
+        )
+        ret = {method_id: []}
+        for result in results.all():
+            ret[method_id].append(result['runtime'])
+        results.close()
+        return ret
+
+    def save_performance_data(self, method_id: str, data: Dict[str, List[float]]):
+        self.delete_performance_data(method_id)
+        for (method_id, perf_data) in data.items():
+            sql = 'INSERT INTO runtimes_by_function (function, runtime) VALUES '
+            for perf in perf_data:
+                self.conn.execute(sql + f'("{method_id}", {perf});')
+
+    def delete_performance_data(self, method_id: str):
+        sql = f'DELETE FROM runtimes_by_function WHERE function = "{method_id}"'
+        self.conn.execute(sql)
+
+
+def function_identifier(f: Callable) -> str:
+    """
+    Given a callable function, return a string that identifies it.
+    Usually that string is just __module__:__name__ but there's a
+    corner case: when __module__ is __main__ (i.e. the callable is
+    defined in the same module as __main__).  In this case,
+    f.__module__ returns "__main__" instead of the file that it is
+    defined in.  Work around this using pathlib.Path (see below).
+
+    >>> function_identifier(function_identifier)
+    'unittest_utils:function_identifier'
+
+    """
+    if f.__module__ == '__main__':
+        from pathlib import Path
+        import __main__
+        module = __main__.__file__
+        module = Path(module).stem
+        return f'{module}:{f.__name__}'
+    else:
+        return f'{f.__module__}:{f.__name__}'
 
 
 def check_method_for_perf_regressions(func: Callable) -> Callable:
@@ -64,43 +177,45 @@ def check_method_for_perf_regressions(func: Callable) -> Callable:
     message if it has become too slow.
 
     """
-    def load_known_test_performance_characteristics():
-        with open(_db, 'rb') as f:
-            return pickle.load(f)
-
-    def save_known_test_performance_characteristics(perfdb):
-        with open(_db, 'wb') as f:
-            pickle.dump(perfdb, f, pickle.HIGHEST_PROTOCOL)
-
     @functools.wraps(func)
     def wrapper_perf_monitor(*args, **kwargs):
+        if config.config['unittests_persistance_strategy'] == 'FILE':
+            filename = config.config['unittests_perfdb_filename']
+            helper = FileBasedPerfRegressionDataPersister(filename)
+        elif config.config['unittests_persistance_strategy'] == 'DATABASE':
+            dbspec = config.config['unittests_perfdb_spec']
+            dbspec = dbspec.replace('<PASSWORD>', scott_secrets.MARIADB_UNITTEST_PERF_PASSWORD)
+            helper = DatabasePerfRegressionDataPersister(dbspec)
+        else:
+            raise Exception(
+                'Unknown/unexpected --unittests_persistance_strategy value'
+            )
+
+        logger.debug(f'Watching {func.__name__}\'s performance...')
+        func_id = function_identifier(func)
+        logger.debug(f'Canonical function identifier = {func_id}')
+
         try:
-            perfdb = load_known_test_performance_characteristics()
+            perfdb = helper.load_performance_data(func_id)
         except Exception as e:
             logger.exception(e)
-            msg = f'Unable to load perfdb from {_db}'
+            msg = 'Unable to load perfdb; skipping it...'
             logger.warning(msg)
+            warnings.warn(msg)
             perfdb = {}
 
-        # This is a unique identifier for a test: filepath!function
-        logger.debug(f'Watching {func.__name__}\'s performance...')
-        func_id = f'{func.__globals__["__file__"]}!{func.__name__}'
-        logger.debug(f'Canonical function identifier = {func_id}')
-
         # cmdline arg to forget perf traces for function
         drop_id = config.config['unittests_drop_perf_traces']
         if drop_id is not None:
-            if drop_id in perfdb:
-                perfdb[drop_id] = []
+            helper.delete_performance_data(drop_id)
 
         # Run the wrapped test paying attention to latency.
         start_time = time.perf_counter()
         value = func(*args, **kwargs)
         end_time = time.perf_counter()
         run_time = end_time - start_time
-        logger.debug(f'{func.__name__} executed in {run_time:f}s.')
 
-        # Check the db; see if it was unexpectedly slow.
+        # See if it was unexpectedly slow.
         hist = perfdb.get(func_id, [])
         if len(hist) < config.config['unittests_num_perf_samples']:
             hist.append(run_time)
@@ -109,9 +224,15 @@ def check_method_for_perf_regressions(func: Callable) -> Callable:
             )
         else:
             stdev = statistics.stdev(hist)
-            limit = hist[-1] + stdev * 5
+            logger.debug(f'For {func.__name__}, performance stdev={stdev}')
+            slowest = hist[-1]
+            logger.debug(f'For {func.__name__}, slowest perf on record is {slowest:f}s')
+            limit = slowest + stdev * 4
+            logger.debug(
+                f'For {func.__name__}, max acceptable runtime is {limit:f}s'
+            )
             logger.debug(
-                f'Max acceptable performace for {func.__name__} is {limit:f}s'
+                f'For {func.__name__}, actual observed runtime was {run_time:f}s'
             )
             if (
                 run_time > limit and
@@ -135,7 +256,7 @@ Here is the current, full db perf timing distribution:
         hist = random.sample(hist, n)
         hist.sort()
         perfdb[func_id] = hist
-        save_known_test_performance_characteristics(perfdb)
+        helper.save_performance_data(func_id, perfdb)
         return value
     return wrapper_perf_monitor