I separately had the same problem recently and created a github issue <https://github.com/web2py/web2py/issues/1999>. If this got implemented please close that issue.
On Sunday, July 15, 2018 at 2:17:25 PM UTC-5, Massimo Di Pierro wrote: > > Good catch. Will implement this. > > On Wednesday, 20 June 2018 14:45:54 UTC+2, Bart wrote: >> >> I have found a workaround for this issue. >> The root cause is probably something in the pyDal connector or psycopg2 >> or threading. I leave the finding of that to the experts. >> >> The workaround is to add code to gluon/scheduler.py to test the >> connection before the rest of the Scheduler.send_heartbeat() function is >> executed. >> If the connection-test fails, a new one is set up: >> Insert this code at the top of the Scheduler.send_heartbeat() function >> >> if self.db_thread: >> # BKR 20180612 check if connection still works, if not -> throw away >> self.db_thread and force reconnect >> try: >> x = self.db_thread(self.db_thread.scheduler_worker.worker_name == >> self.worker_name).select() >> except self.db_thread._adapter.connection.OperationalError: >> self.db_thread = None >> >> >> With this addition, the scheduler works okay. >> >> >> Op woensdag 6 juni 2018 21:26:40 UTC+2 schreef Bart: >>> >>> For a new application, i have installed web2py 2.16.1 under python 3.6 >>> and using psycopg2 2.7.4 for postgresql access. >>> >>> Everything is working okay, except the web2py scheduler. >>> >>> After successfull execution of the first task, the scheduler gives an >>> error in the send_heartbeat function. >>> The task output is correctly stored in the database, with status >>> COMPLETED. The transaction is committed. >>> >>> But then in the first heartbeat after completion, the error below is >>> thrown: >>> >>> Looks like the database connection is lost unexpected. >>> >>> The strange thing is that this is only happening with psycopg2. When the >>> PG8000 connector is used, everything is working fine. >>> I have tested this on my development system (MacBook) >>> >>> On my production system under Ubuntu 16.04, the same thing is happening. >>> >>> Does anyone have a clue? >>> >>> The error: >>> >>> ERROR:web2py.scheduler.MyMac.local#21060:Error retrieving status >>> Exception in thread Thread-30: >>> Traceback (most recent call last): >>> File "/Users/me/PycharmProjects/myapp/web2py/gluon/scheduler.py", line >>> 1168, in send_heartbeat >>> mybackedstatus = db(sw.worker_name == >>> self.worker_name).select().first() >>> File >>> "/Users/me/PycharmProjects/myapp/venv/lib/python3.6/site-packages/pydal/objects.py", >>> >>> line 2250, in select >>> return adapter.select(self.query, fields, attributes) >>> File >>> "/Users/me/PycharmProjects/myapp/venv/lib/python3.6/site-packages/pydal/adapters/base.py", >>> >>> line 762, in select >>> return self._select_aux(sql, fields, attributes, colnames) >>> File >>> "/Users/me/PycharmProjects/myapp/venv/lib/python3.6/site-packages/pydal/adapters/base.py", >>> >>> line 718, in _select_aux >>> rows = self._select_aux_execute(sql) >>> File >>> "/Users/me/PycharmProjects/myapp/venv/lib/python3.6/site-packages/pydal/adapters/base.py", >>> >>> line 712, in _select_aux_execute >>> self.execute(sql) >>> File >>> "/Users/me/PycharmProjects/myapp/venv/lib/python3.6/site-packages/pydal/adapters/__init__.py", >>> >>> line 67, in wrap >>> return f(*args, **kwargs) >>> File >>> "/Users/me/PycharmProjects/myapp/venv/lib/python3.6/site-packages/pydal/adapters/base.py", >>> >>> line 412, in execute >>> rv = self.cursor.execute(command, *args[1:], **kwargs) >>> psycopg2.OperationalError: server closed the connection unexpectedly >>> This probably means the server terminated abnormally >>> before or while processing the request. >>> >>> >>> During handling of the above exception, another exception occurred: >>> >>> Traceback (most recent call last): >>> File >>> "/usr/local/Cellar/python3/3.6.4_2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/threading.py", >>> >>> line 916, in _bootstrap_inner >>> self.run() >>> File "/Users/me/PycharmProjects/myapp/web2py/gluon/scheduler.py", line >>> 637, in run >>> self.send_heartbeat(counter) >>> File "/Users/me/PycharmProjects/myapp/web2py/gluon/scheduler.py", line >>> 1239, in send_heartbeat >>> db.rollback() >>> File >>> "/Users/me/PycharmProjects/myapp/venv/lib/python3.6/site-packages/pydal/base.py", >>> >>> line 704, in rollback >>> self._adapter.rollback() >>> File >>> "/Users/me/PycharmProjects/myapp/venv/lib/python3.6/site-packages/pydal/adapters/__init__.py", >>> >>> line 56, in wrap >>> return f(*args, **kwargs) >>> File >>> "/Users/me/PycharmProjects/myapp/venv/lib/python3.6/site-packages/pydal/adapters/base.py", >>> >>> line 865, in rollback >>> return self.connection.rollback() >>> psycopg2.InterfaceError: connection already closed >>> >> -- Resources: - http://web2py.com - http://web2py.com/book (Documentation) - http://github.com/web2py/web2py (Source code) - https://code.google.com/p/web2py/issues/list (Report Issues) --- You received this message because you are subscribed to the Google Groups "web2py-users" group. 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