Mail server migration strategy

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

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.

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

Hopefully this will minimise any disruption caused by the migration.

Sebb

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