@hazel annoyingly mastodon is about as good as windows when it comes to avoiding throwing errors during normal operation, so it's less about "how much" and more about "what" - this instance gets 500-1000 failures a day, and I'm basically the only active user

common errors that doesn't matter that much:

ActivityPub::ProcessingWorker - Mastodon::RaceConditionError (seems to come from relays letting you know of a post you already got)

ActiveRecord::RecordNotFound: Couldn't find Status with 'id'=<snowflake id> [WHERE "statuses"."deleted_at" IS NULL] (comes from your instance getting a delete but it doesn't have the activity in the database, so it can't delete something that doesn't exist)

most ActiveRecord::StatementInvalid and ActiveRecord::RecordInvalid errors (usually just incoming activities that either doesn't pass validation because the other instance uses different software, or site previews that are in the wrong encoding)

Av::CommandError: error while running command ffmpeg... (media files are a pain, and sometimes you get broken ones - all this means is that you won't get a reencoded local copy)

Mastodon::UnexpectedResponseError for random URLs (mastodon will try to refresh media, sometimes URLs are time limited and break)

NoMethodError: undefined method `file_remote_url=' for #<MediaAttachment:hexstring> Did you mean? file_meta= (I get this whenever a relay forwards a friendica post)

All kinds of connection errors (instances live and die, and some go down at times - it's worth looking into if it's one and the same domain, but often it's just that someone boosted a post they had in their local database)