[DGD] Persistent Users

[Gary]

On 22/09/16 16:02, Blain wrote:
> Bart, if your password and permissions info is stored in a database
> separate from the user object, then that's still not in the swap.  ;)  It's
> just in a large database file.
> 
> I get that people don't mind putting all of their eggs in one basket.
> Keeping individual files on disk is still one big basket that is the disk.
> And it's not like the OS or HDD itself can't cause corruption.  

I'm not too worried about disk corruption. If the server uses ECC memory
and a file system such as ZFS along with a UPS then corruption is mostly
limited to issues DGD itself causes and/or crashes.

[snip]
> If you can retrieve the info for a single user
> from a corrupted swapfile, then there's no problem.  I can't.  I'm not
> savvy enough.  But I can handle individual files all day long.
> 

If the worst happened and an old swap file needed to be used to recover
a players data (or any other data in the mud). I'd probably revert to an
earlier git commit suitable for the backup state dump, fire up the
server and add a little extra code to write out the data to a file.

That could then be imported into the running mud (once a little import
code is added anyway).

Granted it's more involved than just going into a backup set and pulling
out a file and copying that over, but not overly so.

Disk corruption (and to an extent memory errors) causing issues with a
running system is a concern, but I would think careful selection of
hardware and file system should mitigate the issue.

Regards,

Gary