A backup is a directory <stamp>-<kind> under Backups:Root (/var/lib/privapub/backups, 2770, files 0640), written as
.partial and renamed once whole: a manifest (host, build, newest migration, each collection's count, size, sha256 and
indexes, what was left out and why, the media list), each collection as gzipped canonical Extended JSON read raw, and
hard links to the files of untrashed media rows (copies where a link can't be made). On a replica set every collection
is read in one snapshot session. Never in a backup: the statistics salt, jobs, recovery codes, sessions, the
maintenance lock and the configuration's copy with its SMTP password.
One backup or restore at a time (MaintenanceLock, a heartbeat document), and the janitor purges nothing meanwhile.
BackupScheduler backs up nightly at 03:30 UTC (or at once after missing a night); rotation keeps 7 daily, 4 weekly,
3 pre-deploy and 3 pre-restore backups. CLI: admin backup [--kind] [--db-only], admin backups, admin backup verify;
these run before migrations, so the deploy's own pre-deploy backup, which replaces mongodump, is of the database as the
live build left it. EntityMaps.Warm runs once under a lock, since test hosts now boot side by side.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw
Infrastructure/Data/Indexes runs at every start, after the migrations:
unique on Post/DmPost ObjectURI, ForeignAvatar ActorURI, the Follower
triple, RootToAvatar, RootUser UserName and ReservedName; plain indexes on
the lookups the services actually make (PublicKeyId, author and group
post listings, ParticipantsKey, the delivery queue).
Migration _001 runs first and removes the duplicates the races could
already have left (keeping the newest actor row, the oldest post, the
accepted follower), then fills ReservedName from every avatar and group.
ReservedName is one username space for personas, groups and the instance:
a name is reserved by an insert the unique index arbitrates, before the
avatar or group is saved, so two simultaneous sign-ups cannot both get it.
A short list of names (admin, support, abuse, postmaster, ...) is never
available.
EntityMaps.Warm touches every entity's collection one at a time before
anything else runs. MongoDB.Entities maps the Entity base class on first
touch, and two types mapped at once throw "An item with the same key has
already been added" and stay broken for the life of the process; the
parallel test run hit it, and the delivery worker racing a request could
have too.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB
thepraandClaude Opus 5.5