Initialize counters at zero (#54)

* Keep track of all the functions we decorate and provide utilities to display them

* Clean up admin_panel a bit, esp function bookkeeping

* Prototype "cdn" example

* Update the HTML we serve

* Fix readme

* Remove http server for admin panel (old code)

* Prototype "initialize at zero" behavior for counters

* Fix tracker type and type issues with caller param on initialization

* Remove admin panel section from README

* Remove all code related to admin paenl

* Add tests for initializing at zero

* Fix docstring typo

* Add tests for initializing at zero with objective name

* Change initialize_at_zero to initialize_counters

* PR Feedback: Prefer consistency in use of positional args

* Update changelog

---------

Co-authored-by: Brett Beutell <[email protected]>

CHANGELOG.md

@@ -12,7 +12,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Added
 
--
+- Initialize counter metrics at zero #54
 
 ### Changed
 
@@ -28,11 +28,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Fixed
 
-- Fixed decorator async function handling (#55)
-
 ### Security
 
-- Update requests, starlette, fastapi dependencies used by the examples
+-
 
 ## [0.6](https://github.com/autometrics-dev/autometrics-py/releases/tag/0.6) - 2023-06-23
 

src/autometrics/__init__.py

@@ -1,3 +1 @@
 from .decorator import *
-
-from .admin_panel import *

src/autometrics/decorator.py

@@ -7,7 +7,6 @@
 from typing_extensions import ParamSpec
 from .objectives import Objective
 from .tracker import get_tracker, Result
-from .admin_panel import register_function_info
 from .utils import get_module_name, get_caller_function, append_docs_to_docstring
 
 
@@ -42,6 +41,14 @@ def autometrics(
 ):
     """Decorator for tracking function calls and duration. Supports synchronous and async functions."""
 
+    def register_function_info(
+        function: str,
+        module: str,
+    ):
+        get_tracker().initialize_counters(
+            function=function, module=module, objective=objective
+        )
+
     def track_start(function: str, module: str):
         get_tracker().start(
             function=function, module=module, track_concurrency=track_concurrency

src/autometrics/test_decorator.py

@@ -34,6 +34,16 @@ async def error_async_function():
     raise RuntimeError("This is a test error")
 
 
+def never_called_function():
+    """This is a sync function that should never be called. Used for testing initialization at zero for counters"""
+    raise RuntimeError("This function should never be called")
+
+
+async def never_called_async_function():
+    """This is an async function that should never be called. Used for testing initialization at zero for counters"""
+    raise RuntimeError("This function should never be called")
+
+
 tracker_types = [TrackerType.PROMETHEUS, TrackerType.OPENTELEMETRY]
 
 
@@ -257,3 +267,81 @@ async def test_async_exception(self):
 
         duration_sum = f"""function_calls_duration_sum{{function="{function_name}",module="test_decorator",objective_latency_threshold="",objective_name="",objective_percentile=""}}"""
         assert duration_sum in data
+
+    def test_initialize_counters_sync(self):
+        """This is a test to see if the function calls metric initializes at 0 after invoking the decorator."""
+
+        function_name = never_called_function.__name__
+        wrapped_function = autometrics(never_called_function)
+        # NOTE - Do not call the function! We want to see if we get counter data for it
+
+        blob = generate_latest()
+        assert blob is not None
+        data = blob.decode("utf-8")
+
+        total_count_ok = f"""function_calls_count_total{{caller="",function="{function_name}",module="test_decorator",objective_name="",objective_percentile="",result="ok"}} 0.0"""
+        assert total_count_ok in data
+
+        total_count_error = f"""function_calls_count_total{{caller="",function="{function_name}",module="test_decorator",objective_name="",objective_percentile="",result="error"}} 0.0"""
+        assert total_count_error in data
+
+    def test_initialize_counters_sync_with_objective(self):
+        """This is a test to see if the function calls metric initializes at 0 after invoking the decorator."""
+
+        objective_name = "test_objective"
+        success_rate = ObjectivePercentile.P90
+        objective = Objective(name=objective_name, success_rate=success_rate)
+
+        function_name = never_called_function.__name__
+        wrapped_function = autometrics(objective=objective)(never_called_function)
+        # NOTE - Do not call the function! We want to see if we get counter data for it
+
+        blob = generate_latest()
+        assert blob is not None
+        data = blob.decode("utf-8")
+
+        total_count_ok = f"""function_calls_count_total{{caller="",function="{function_name}",module="test_decorator",objective_name="{objective_name}",objective_percentile="{success_rate.value}",result="ok"}} 0.0"""
+        assert total_count_ok in data
+
+        total_count_error = f"""function_calls_count_total{{caller="",function="{function_name}",module="test_decorator",objective_name="{objective_name}",objective_percentile="{success_rate.value}",result="error"}} 0.0"""
+        assert total_count_error in data
+
+    @pytest.mark.asyncio
+    async def test_initialize_counters_async(self):
+        """This is a test to see if the function calls metric initializes at 0 after invoking the decorator for an async function"""
+
+        function_name = never_called_async_function.__name__
+        wrapped_function = autometrics(never_called_async_function)
+        # NOTE - Do not call the function! We want to see if we get counter data for it even without ever calling it
+
+        blob = generate_latest()
+        assert blob is not None
+        data = blob.decode("utf-8")
+
+        total_count_ok = f"""function_calls_count_total{{caller="",function="{function_name}",module="test_decorator",objective_name="",objective_percentile="",result="ok"}} 0.0"""
+        assert total_count_ok in data
+
+        total_count_error = f"""function_calls_count_total{{caller="",function="{function_name}",module="test_decorator",objective_name="",objective_percentile="",result="error"}} 0.0"""
+        assert total_count_error in data
+
+    @pytest.mark.asyncio
+    async def test_initialize_counters_async_with_objective(self):
+        """This is a test to see if the function calls metric initializes at 0 after invoking the decorator for an async function"""
+
+        objective_name = "test_objective"
+        success_rate = ObjectivePercentile.P90
+        objective = Objective(name=objective_name, success_rate=success_rate)
+
+        function_name = never_called_async_function.__name__
+        wrapped_function = autometrics(objective=objective)(never_called_async_function)
+        # NOTE - Do not call the function! We want to see if we get counter data for it even without ever calling it
+
+        blob = generate_latest()
+        assert blob is not None
+        data = blob.decode("utf-8")
+
+        total_count_ok = f"""function_calls_count_total{{caller="",function="{function_name}",module="test_decorator",objective_name="{objective_name}",objective_percentile="{success_rate.value}",result="ok"}} 0.0"""
+        assert total_count_ok in data
+
+        total_count_error = f"""function_calls_count_total{{caller="",function="{function_name}",module="test_decorator",objective_name="{objective_name}",objective_percentile="{success_rate.value}",result="error"}} 0.0"""
+        assert total_count_error in data

src/autometrics/tracker/opentelemetry.py

@@ -83,6 +83,7 @@ def __count(
         objective: Optional[Objective],
         exemplar: Optional[dict],
         result: Result,
+        inc_by: int = 1,
     ):
         objective_name = "" if objective is None else objective.name
         percentile = (
@@ -91,7 +92,7 @@ def __count(
             else objective.success_rate.value
         )
         self.__counter_instance.add(
-            1,
+            inc_by,
             attributes={
                 "function": function,
                 "module": module,
@@ -184,3 +185,14 @@ def finish(
                     "module": module,
                 },
             )
+
+    def initialize_counters(
+        self,
+        function: str,
+        module: str,
+        objective: Optional[Objective] = None,
+    ):
+        """Initialize tracking metrics for a function call at zero."""
+        caller = ""
+        self.__count(function, module, caller, objective, None, Result.OK, 0)
+        self.__count(function, module, caller, objective, None, Result.ERROR, 0)

src/autometrics/tracker/prometheus.py

@@ -69,6 +69,7 @@ def _count(
         objective: Optional[Objective] = None,
         exemplar: Optional[dict] = None,
         result: Result = Result.OK,
+        inc_by: int = 1,
     ):
         """Increment the counter for the function call."""
         objective_name = "" if objective is None else objective.name
@@ -85,7 +86,7 @@ def _count(
             caller,
             objective_name,
             percentile,
-        ).inc(1, exemplar)
+        ).inc(inc_by, exemplar)
 
     def _histogram(
         self,
@@ -146,3 +147,14 @@ def finish(
 
         if track_concurrency:
             self.prom_gauge_concurrency.labels(function, module).dec()
+
+    def initialize_counters(
+        self,
+        function: str,
+        module: str,
+        objective: Optional[Objective] = None,
+    ):
+        """Initialize tracking metrics for a function call at zero."""
+        caller = ""
+        self._count(function, module, caller, objective, None, Result.OK, 0)
+        self._count(function, module, caller, objective, None, Result.ERROR, 0)

src/autometrics/tracker/tracker.py

@@ -36,6 +36,14 @@ def finish(
     ):
         """Finish tracking metrics for a function call."""
 
+    def initialize_counters(
+        self,
+        function: str,
+        module: str,
+        objective: Optional[Objective] = None,
+    ):
+        """Initialize (counter) metrics for a function at zero."""
+
 
 class TrackerType(Enum):
     """Type of tracker."""