#22 Consistent, automated backups
Deities make backups by copying the data directory.
The server can't make updates to the game state on disk
atomic. Therefore, copying the game state while the
server runs may result in an inconsistent state. This
is unsafe.
I propose simple means for safe backup, which also make
it easier for deities to implement sensible backup plans.
Auto-save: Periodically flush data to disk
(configurable schedule), then run an external program
specified in econfig (let's call it `ebackup') to do
the actual backup. Always do it right before and right
after the update. Since the server waits for ebackup's
completion, the backup will be consistent. ebackup
should implement suitable policy (how long to retain
backups, where to store them, etc.). We provide a
default ebackup that suits our needs.
Manual save: Have a new deity command `backup', which
flushes data to disk, then runs ebackup.
Logged In: YES
user_id=596270
4.2.20's pre_update_hook allows auto-save before the update.