After stopping MonetDB, mserver still appear to be running, and restart is now impossible. Does anyone know why?

Question

I'm new to using MonetDB for my data. My dataset is currently about 1TB in size (spread across lots of tables).

About an hour or two ago, I ran monetdbd stop db and monetdb stop db (both the dbfarm and the database are named "db").

I would have expected this to stop every MonetDB process, but I just noticed via htop that there are several mserver processes still running.

Additionally, when I try to run monetdb start db, I get an error (see the below logs). I suspect the reason monetdb crashes when I try to restart has something to do with the stop command from earlier not yet being totally finished with the shutdown procedure, but please correct me if I'm wrong.

2023-03-15 17:13:29 MSG merovingian[247517]: caught SIGTERM, starting shutdown sequence
2023-03-15 17:11:16 MSG control[247517]: (local): served status list
2023-03-15 17:13:29 MSG control[247517]: control channel closed
2023-03-15 17:13:30 MSG merovingian[247517]: Merovingian 11.45.7 stopped
2023-03-15 17:13:35 MSG merovingian[247584]: Merovingian 11.45.7 (Sep2022) starting
2023-03-15 17:13:35 MSG merovingian[247584]: monitoring dbfarm /root/db
2023-03-15 17:13:35 MSG merovingian[247584]: accepting connections on TCP socket 0.0.0.0:50000
2023-03-15 17:13:35 MSG merovingian[247584]: accepting connections on UNIX domain socket /tmp/.s.monetdb.50000
2023-03-15 17:13:35 MSG discovery[247584]: listening for UDP messages on 0.0.0.0:50000 
2023-03-15 17:13:35 MSG control[247584]: accepting connections on UNIX domain socket /tmp/.s.merovingian.50000
2023-03-15 17:13:53 MSG control[247584]: (local): served status list
2023-03-15 17:13:53 MSG merovingian[247584]: database 'db' has crashed after start on 2023-03-15 17:11:35, attempting restart, up min/avg/max: 12m/13h/1d, crash average: 1.00 0.40 0.13 (6-2=4) 
2023-03-15 17:13:54 MSG db[247593]: arguments: /usr/bin/mserver5 --dbpath=/root/db/db --set=merovingian_uri=mapi:monetdb://research:50000/db --set=mapi_listenaddr=none --set=mapi_usock=/root/db/db/.mapi.sock --set=monet_vault_key=/root/db/db/.vaultkey --set=gdk_nr_threads=12 --set=max_clients=64 --set=sql_optimizer=default_pipe
2023-03-15 17:14:00 MSG merovingian[247584]: database 'db' (-1) has crashed with signal SIGSEGV (dumped core)
2023-03-15 17:14:00 ERR control[247584]: (local): failed to fork mserver: database 'db' has crashed after starting, manual intervention needed, check monetdbd's logfile (merovingian.log) for details

Has anyone encountered this issue before?

EDIT: After searching, it appears to be a known issue. See other GitHub issues below: https://github.com/MonetDB/MonetDB/issues/3243 https://github.com/MonetDB/MonetDB/issues/7152

After stopping MonetDB, mserver still appear to be running, and restart is now impossible. Does anyone know why?

Answers (1)

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