Close DB connection before job completion

RQ workers create a fork to run the function. The issue arises
when, after completing the job, the MariaDB logs display the
warning:  `Aborted connection to db. Got an error reading
communication packets`. This change ensures the database
connection is closed before the fork ends, preventing the
warning from appearing.

Signed-off-by: Jose Javier Merchante <jjmerchante@bitergia.com>

releases/unreleased/connection-closed-when-job-is-executed.yml

@@ -0,0 +1,12 @@
+---
+title: Connection closed when job is executed
+category: fixed
+author: Jose Javier Merchante <jjmerchante@bitergia.com>
+issue: null
+notes: >
+  RQ workers create a fork to run the jobs. The issue arises
+  when, after completing the job, the MariaDB logs display the
+  warning: `Aborted connection to db. Got an error reading
+  communication packets`. This change ensures the database
+  connection is closed before the fork ends, preventing the
+  warning from appearing.

sortinghat/config/settings.py

@@ -292,6 +292,10 @@
     }
 }
 
+RQ = {
+    'JOB_CLASS': 'sortinghat.core.jobs.SortingHatJob'
+}
+
 #
 # SortingHat Multi-tenant
 #

sortinghat/core/jobs.py

@@ -28,7 +28,8 @@
 import django_rq.utils
 import rq
 import redis.exceptions
-from django.db import IntegrityError, transaction
+from django.db import IntegrityError, transaction, connection
+from rq.job import Job
 
 from .db import find_individual_by_uuid, find_organization
 from .api import enroll, merge, update_profile, add_scheduled_task, delete_scheduled_task
@@ -140,6 +141,21 @@ def job_in_tenant(job, tenant):
     return sorted_jobs
 
 
+class SortingHatJob(Job):
+    """Custom RQ Job class for SortingHat jobs.
+
+    This class closes the db connection before finishing
+    the job to avoid the 'aborted connection' error in
+    the database.
+
+    See also https://github.com/rq/django-rq/issues/17
+    """
+    def perform(self):
+        result = super().perform()
+        connection.close()
+        return result
+
+
 @django_rq.job
 @job_using_tenant
 def recommend_affiliations(ctx, uuids=None, last_modified=MIN_PERIOD_DATE):