[MM3-users] My Server is unable to connect to Mailman REST API few times

Hi Team,

         I am currently running Mailman 3 with version 3.3.1 and in

built postfix version 2.10.1-6 on RHEL 7.5 with PostgreSQL 11.7 version with default values in production environment from the past 4 months almost. As of now, we are having around 1327 lists created on this.

         When I am trying to do some operations like creating the

lists, deleting the lists or accessing the lists through the GUI, I am getting the below error. If I am trying to do the operations through API or through mailman shell, still I am not able to connect to the API.

Something went wrong

Mailman REST API not available. Please start Mailman core.

          But my mailman core was working fine in the background. At

the same time I was able to do other operations on a few other lists.

          By the time I am getting the above error, the mailman.log

recorded the below messages.

*[2020-09-16 12:49:08 +0530] [2600] [CRITICAL] WORKER TIMEOUT (pid:20234)*

*[2020-09-16 12:49:08 +0530] [20234] [INFO] Worker exiting (pid: 20234)*

*[2020-09-16 12:49:09 +0530] [21042] [INFO] Booting worker with pid: 21042*

          My mailman.cfg configuration is as below. The timeout value

is the default value. I did not set any customized value.

*(venv3) [root@lsmgr mailman]# grep -v ^# /var/lib/mailman/mailman/var/etc/mailman.cfg*

*[archiver.hyperkitty]*

*class: mailman_hyperkitty.Archiver*

*enable: yes*

*configuration: /var/lib/mailman/mailman-hyperkitty/mailman-hyperkitty.cfg*

*[mta]*

*incoming: mailman.mta.postfix.LMTP*

*outgoing: mailman.mta.deliver.deliver*

*lmtp_host: 0.0.0.0*

*lmtp_port: 8024*

*smtp_host: localhost*

*smtp_port: 25*

*[webservice]*

*workers: 10*

*[database]*

*class: mailman.database.postgresql.PostgreSQLDatabase*

*url: postgres://<postgresdbuser>:<postgresdbpassword>@127.0.0.1/mailman <http://127.0.0.1/mailman>*

          Then as per the suggestion I got earlier I configured the

[webservice] section in the above file as below.

*[webservice]*

*configuration: /var/lib/mailman/mailman/var/etc/gunicorn.cfg*

•        [root@lsmgr logs]# cat

  /var/lib/mailman/mailman/var/etc/gunicorn.cfg*

*[gunicorn]*

*workers = 10*

*timeout = 90 *

After the above configuration, I found many errors like below in mailman.log file:

*sqlalchemy.exc.NoSuchColumnError: "Could not locate column in row for column 'pended.id <http://pended.id>'"*

*sqlalchemy.exc.ResourceClosedError: This result object does not return rows. It has been closed automatically.*

*sqlalchemy.exc.DatabaseError: (psycopg2.DatabaseError) error with status PGRES_TUPLES_OK and no message from the libpq*

The above might be few of the errors. FYI, for the creation of each list, it is taking almost around 15 to 20 minutes. After multiple times of the above error messages, at some time, I am fortunately getting the list created or some other operation getting done.

          I found the same scenario when the workers are from default 2

to 10. I don't understand where exactly I need to focus to solve the issue.

          Please let me know if I have to share any other details for

you to suggest to me.

-- Thanks & Regards, Shashi Kanth.K 9052671936

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