Adding extra logging to celery tasks ans gunicorn, specifically log on SIGTERM and SIGINIT so that we can track better when an app restarts and why it restarts e.g. when it restarts after another signal.

app/celery/scheduled_tasks.py

@@ -3,6 +3,7 @@ from datetime import (
     timedelta
 )
 
+from celery.signals import worker_process_shutdown
 from flask import current_app
 from sqlalchemy.exc import SQLAlchemyError
 from notifications_utils.s3 import s3upload
@@ -45,6 +46,11 @@ from app.config import QueueNames, TaskNames
 from app.utils import convert_utc_to_bst
 
 
+@worker_process_shutdown.connect
+def worker_process_shutdown(sender, signal, pid, exitcode):
+    current_app.logger.info('Scheduled tasks worker shutdown:: PID: {} Exitcode: {}'.format(pid, exitcode))
+
+
 @notify_celery.task(name="remove_csv_files")
 @statsd(namespace="tasks")
 def remove_csv_files(job_types):