Re: Mail server migration strategy

[sebb <se...@gmail.com>]

On Thu, 28 Apr 2022 at 19:18, sebb <se...@gmail.com> wrote:
>
> Mailing lists are due to be migrated to a new server.
>
> This affects the data files generated and pushed to Whimsy which are
> used to support mail list reporting.
>
> Rather than change the code to try to merge input from two sources, it
> seemed simpler to merge the data from the old and new servers to
> generate a single source. Once migration is complete, merging can be
> switched off.
>
> The strategy is:
> data from the existing server is pushed to Whimsy under /srv/subscriptions1
> data from the new server is pushed to Whimsy under /srv/subscriptions2
>
> These pushes are done by cron jobs that run every 20 mins.
> Following every update, the data will be merged to
> /srv/subscriptions, where the code expects to find it.

This is now in place, so mailing list data should now include migrated
lists (so far only infra.a.o; others are due to follow soon).

> Once migration is complete, merging can be disabled, and the new
> server can be updated to push its data directly to /srv/subscriptions.

The plan is:
- drop the hourly jobs that do the merging
- change the two apmail scripts (listmodsubs.sh and
whimsy_qmail_ids.sh) to push to /srv/subscriptions from the new server
only.

> Hopefully this will minimise any disruption caused by the migration.
>
> Sebb