If you look at bug 849912 from nearly two months ago, its sentry error has been deleted: http://sentry.dmz.phx1.mozilla.com/amo-ops/marketplace-stage-webpay/group/11855/ Can we retain errors longer, like 6 months maybe? I'm not sure why we need to delete them at all but 6 months is probably enough time.
I may have pruned sentry events for webpay when trying to fix bug 865145, sorry. I am not seeing a configuration option for retention but I believe that events will not get pruned automatically. For addons-dev I am seeing alerts that go as far back as 7 months. I am trying to find out more information if this is a configurable option, I will update the bug when I have the info.
Sentry has a built-in management command 'cleanup' to truncate older events . For now, I don't think we need to truncate events but can revisit in the future if we are running out of space and/or having performance issues with sentry.  https://github.com/getsentry/sentry/blob/master/src/sentry/management/commands/cleanup.py
ok, thanks. If you need to free up space maybe you can only cleanup old events with the --days option?