54 figure out a better alternative for the celery subprocess in subprocess problem

dev-requirements.txt

@@ -80,7 +80,9 @@ coolprop==6.6.0
     #   -c requirements.txt
     #   mesido
 coverage[toml]==7.4.1
-    # via pytest-cov
+    # via
+    #   coverage
+    #   pytest-cov
 exceptiongroup==1.2.0
     # via pytest
 flake8==6.1.0
@@ -158,7 +160,7 @@ omotes-sdk-protocol==0.0.8
     # via
     #   -c requirements.txt
     #   omotes-sdk-python
-omotes-sdk-python==0.0.15
+omotes-sdk-python==0.0.16
     # via
     #   -c requirements.txt
     #   omotes-grow-worker (pyproject.toml)

pyproject.toml

@@ -26,7 +26,7 @@ requires-python = ">=3.10"
 dependencies = [
     "python-dotenv ~= 1.0.0",
     "mesido ~= 0.1.3.1",
-    "omotes-sdk-python ~= 0.0.15"
+    "omotes-sdk-python ~= 0.0.16"
 ]
 
 [project.optional-dependencies]
@@ -66,7 +66,7 @@ requires = [
 enabled = true
 
 [tool.pytest.ini_options]
-addopts = "--cov=grow_worker --cov-report html --cov-report term-missing --cov-fail-under 25"
+addopts = "--cov=grow_worker --cov-report html --cov-report term-missing --cov-fail-under 15"
 
 [tool.coverage.run]
 source = ["src"]

requirements.txt

@@ -71,7 +71,7 @@ numpy==1.22.4
     #   scipy
 omotes-sdk-protocol==0.0.8
     # via omotes-sdk-python
-omotes-sdk-python==0.0.15
+omotes-sdk-python==0.0.16
     # via omotes-grow-worker (pyproject.toml)
 ordered-set==4.1.0
     # via pyecore

src/grow_worker/worker.py

@@ -1,6 +1,9 @@
 import base64
 import logging
 import multiprocessing
+import multiprocessing.pool
+import signal
+import time
 from multiprocessing.process import current_process
 import os
 from pathlib import Path
@@ -23,6 +26,16 @@
 GROW_TASK_TYPE = GrowTaskType(os.environ.get("GROW_TASK_TYPE"))
 
 
+class EarlySystemExit(Exception):
+    """Wrapper for `SystemExit` exception.
+
+    To ensure that the worker process does not shutdown but rather handles the `SystemExit` as an
+    error
+    """
+
+    ...
+
+
 def run_mesido(input_esdl: str) -> str:
     """Run mesido using the specific workflow.
 
@@ -40,30 +53,65 @@ def run_mesido(input_esdl: str) -> str:
     influxdb_host = os.environ.get("INFLUXDB_HOSTNAME", "localhost")
     influxdb_port = int(os.environ.get("INFLUXDB_PORT", "8086"))
 
-    logger.info("Will write result profiles to influx: {}. At {}:{}",
-                write_result_db_profiles,
-                influxdb_host,
-                influxdb_port)
-
-    solution: GROWProblem = mesido_func(
-        mesido_workflow,
-        base_folder=base_folder,
-        esdl_string=base64.encodebytes(input_esdl.encode("utf-8")),
-        esdl_parser=ESDLStringParser,
-        write_result_db_profiles=write_result_db_profiles,
-        influxdb_host=influxdb_host,
-        influxdb_port=influxdb_port,
-        influxdb_username=os.environ.get("INFLUXDB_USERNAME"),
-        influxdb_password=os.environ.get("INFLUXDB_PASSWORD"),
-        influxdb_ssl=False,
-        influxdb_verify_ssl=False,
-        update_progress_function=None,
-        profile_reader=InfluxDBProfileReader,
+    logger.info(
+        "Will write result profiles to influx: {}. At {}:{}",
+        write_result_db_profiles,
+        influxdb_host,
+        influxdb_port,
     )
+    try:
+        solution: GROWProblem = mesido_func(
+            mesido_workflow,
+            base_folder=base_folder,
+            esdl_string=base64.encodebytes(input_esdl.encode("utf-8")),
+            esdl_parser=ESDLStringParser,
+            write_result_db_profiles=write_result_db_profiles,
+            influxdb_host=influxdb_host,
+            influxdb_port=influxdb_port,
+            influxdb_username=os.environ.get("INFLUXDB_USERNAME"),
+            influxdb_password=os.environ.get("INFLUXDB_PASSWORD"),
+            influxdb_ssl=False,
+            influxdb_verify_ssl=False,
+            update_progress_function=None,
+            profile_reader=InfluxDBProfileReader,
+        )
+    except SystemExit as e:
+        raise EarlySystemExit(e)
 
     return cast(str, solution.optimized_esdl_string)
 
 
+def kill_pool(pool: multiprocessing.pool.Pool) -> None:
+    """Terminate all the process of a multiprocessing.Pool with SIGKILL.
+
+    Found here: https://stackoverflow.com/a/47580796
+
+    multiprocessing.Pool.terminate does not provide a way to give a different signal than SIGTERM
+    so this function hooks into the internals to properly handle sending SIGKILL to all processes in
+    the pool.
+
+    :param pool: The multiprocessing to kill all processes in.
+    """
+    #
+    # stop repopulating new child
+    pool._state = multiprocessing.pool.TERMINATE  # type: ignore[attr-defined]
+    pool._worker_handler._state = multiprocessing.pool.TERMINATE  # type: ignore[attr-defined]
+    for p in pool._pool:  # type: ignore[attr-defined]
+        if p.is_alive():
+            logger.warning("Sending SIGKILL to pool process with pid %s", p.pid)
+            os.kill(p.pid, signal.SIGKILL)
+    # .is_alive() will reap dead process
+    wait_till = time.time() + 5.0
+    while (
+        any(p.is_alive() for p in pool._pool)  # type: ignore[attr-defined]
+        and time.time() < wait_till
+    ):
+        pass
+    logger.warning("All processes in pool have been terminated.")
+    pool.terminate()
+    logger.warning("Forceful pool termination completed.")
+
+
 def grow_worker_task(
     input_esdl: str, params_dict: ParamsDict, update_progress_handler: UpdateProgressHandler
 ) -> str:
@@ -85,10 +133,15 @@ def grow_worker_task(
     #  subprocesses from being created. This does introduce the issue that if this
     #  process is killed/cancelled/revoked, the subprocess will continue as a zombie process.
     #  See https://github.com/Project-OMOTES/optimizer-worker/issues/54
-    current_process()._config['daemon'] = False  # type: ignore[attr-defined]
+    current_process()._config["daemon"] = False  # type: ignore[attr-defined]
 
     with multiprocessing.Pool(1) as pool:
-        output_esdl = pool.map(run_mesido, [input_esdl])[0]
+        try:
+            output_esdl = pool.map(run_mesido, [input_esdl])[0]
+        except SystemExit as e:
+            logger.warning("During pool the worker was requested to quit: %s %s", type(e), e)
+            kill_pool(pool)
+            raise
 
     return output_esdl