A full backup opened its repository at the start of a step and wrote the
catalog at the end of it, without the catalog lock. A per-user export or
restore that wrote the catalog in between could lose its entry, or the
snapshot could lose its own.
The final step now only stores the snapshot object and moves the run to a
new 'commit' phase. BackupService then records the snapshot under the
catalog lock, from a repository opened inside that lock; if the lock is
busy, the next step retries the commit. Repository::writeSnapshot() keeps
its old behaviour as putSnapshot() plus recordSnapshot().
BackupService starts a run per location (database dump in one
transaction, then config + data directory as a resumable file run),
stores the state in ngb_runs after every step, locks a run while a step
executes and records the snapshot. Previews, logs, updater backups and
per-user cache/uploads are excluded (TreeWalker now supports patterns).
BackupJob (every 5 min) starts the daily schedule and steps running runs
with a short budget under web cron and a long one under system cron.
occ: backup:run, backup:status, backup:list.
Tested on NC34/PostgreSQL: first run 128 files / 1 GiB in 64 s (443 MiB
uploaded to S3), unchanged second run 2 s / 0 bytes; a background run to
SFTP completed through cron.php.
TreeWalker walks one or more roots in a stable segment-wise order with
exclusions and resumes after a cursor; ParentCursor merge-joins the
previous snapshot in the same order. BackupRun no longer keeps a file
list or the parent's entries in memory or in its state.
- detect files changing during reading or between resumable steps and
re-read them (size/mtime/ctime/inode), spike F overwrites mid-run
- drop pending blob ids when a pack or index upload fails
- dump and restore PostgreSQL sequence state exactly, bound parameters,
validated catalog names; spike C checks all sequences exactly
- keep invalid UTF-8 byte-exact (tagged base64)
- refuse large tables without a primary key
- StorageBackend: check write/flush/close results, validate base path
- user_migration import/export: root paths, intermediate folders,
partial writes, read errors
- spikes: never touch an existing account, own fixtures, 512M note
BackupRun is a resumable state machine: each step works until a deadline,
uploads its pack and tree segment, and returns the state; large files are
resumed at the next blob. Snapshot is written last.
Spike F: 200 MiB file resumed across steps in separate processes; with 6
random kill -9 the run completes and restores bit-identically.
spikes/RESULTS.md summarises phase 0 and the findings for the plan.
dillard