[Act] Act services moving on a new server

[Salve J Nilsen]

Sébastien Aperghis-Tramoni said:
>
> Steps:
> - shutdown all services on spectre
> - dump all PostgreSQL databases
> - rsync everything a last time from spectre to phantom
> - reimport all PostgreSQL databases
> - startup all services on phantom
>
> Executing these steps should roughly take an hour, given that
> data have been rsync'd every 2 hours since weeks. But as said,
> DNS propagation will make the disruption longer for people still
> trying to reach spectre. This can be mitigated to some degree
> by reducing the TTL of the records.
>
> Unless I oversaw something, migrating over the next days should
> be an appropriate time.
>
> Opinions?

0) Make a cronological task list, with ALL necessary steps written down. Even 
the minor ones!

1) Do the $NEW_TTL change right now, so people with $CURRENT_TTL can have time 
to update their DNS cache. Then wait with any migration until $CURRENT_TTL 
time has passed. :)

2) Make a "this site is under maintainance" static webpage, that one can put 
up during the migration. Doesn't have to be more than a catch-all mod_rewrite 
rule pointing to a static webpage containing a few words of apology, a smiley 
and an ETA for when the sites are expected to be up again.

3) IMHO, at least admins of currently active sites should get a separate 
notice mail telling about the impending doom, ETA, duration, etc. :) This is 
also so they can give notice to their users/staff as they deem necessary.

4) Pick a downtime a few days *after* a conference, and as long as possible 
before the next conference, so signup disruption is minimized.

5) Thanks for the effort! :D


- Salve

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