Commit Graph
4 Commits
Author SHA1 Message Date
Chris Lu b3be2f5449 filer.backup, filer.sync: stop sharing resume checkpoints across destinations (#10934)
* filer.backup: key the checkpoint by source path and sink destination

The checkpoint id hashed only sink name + directory, so two backups to
different buckets or endpoints sharing a directory layout advanced one
checkpoint: whichever job was running pushed the shared offset forward,
and a stopped or failing job later resumed from the other's position,
silently skipping changes. Backups of different source paths to the same
destination shared a checkpoint the same way.

Each sink now reports a destination identity (endpoint or account,
bucket or container, directory) and the checkpoint is keyed by the
source path plus that identity. Reads fall back to the historical
name+directory key when the new key has no value, so existing backups
resume where they left off; writes go only to the new key.

* filer.sync: include the target path in the offset key

The offset stored on the target filer was keyed by source path and
source filer signature only, so two syncs from the same source cluster
and path to different directories on the same target cluster advanced
one shared checkpoint, and the slower one could resume past events it
never applied. The target path now participates in the key; "/" keeps
the historical form, and a sync with a non-root target path falls back
to the historical key once when its own key has no value yet.

* join checkpoint key fields with NUL so they cannot alias

A path or configuration value spelling out the separator could
concatenate two different field tuples to the same checkpoint key.
NUL cannot appear in a CLI path argument or any sane configuration
value, making the encoding injective.
2026-08-24 19:30:20 -07:00
Jaehoon KimandClaude Fable 5 c17aebeecf fix(filer.backup): prevent silent backup data loss on transient not-found (#10295)
* fix(filer.backup): stop silently dropping events on transient not-found

Under a write burst, filer.backup could consume a metadata event (advancing
the persisted offset) without replicating the file, with no error logged:

1. filersink CreateEntry/UpdateEntry swallowed replicateChunks errors
   (glog.Warningf + return nil), so the offset advanced past entries that
   were never written.
2. The manifest-chunk branch of replicateChunks resolved via LookupFileId
   with no retry, unlike the data-chunk branch — transient lookup races
   dropped exactly the large manifest-backed files while small
   inline-content siblings landed.
3. isIgnorable404 matched "LookupFileId" / "volume id ... not found",
   misclassifying those races as genuine source 404s at the backup layer.

Fix: on a replicateChunks failure the filer sink now skips only when the
live source has moved past the replayed version (deleted or strictly-newer
mtime) — lossless, a later event carries the current content — and
propagates otherwise so the event is retried. The manifest resolve retries
transient errors like the data-chunk path. isIgnorable404 is narrowed to
genuine 404s; non-filer sinks and the initial-snapshot walk, which relied
on the broad match as their only lossless-skip valve, now make the same
live-source decision (filersink.SourceSupersedes) instead of retrying
forever on a permanently gone volume.

Tests cover propagation of unconfirmed lookup failures, the narrowed 404
classification, and the supersession guards.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(filer.backup): derive supersession path with directory fallback

eventSourceSuperseded built the source path from NewParentPath alone.
Legacy metadata events (persisted by older filers) carry an empty
NewParentPath, so the probe looked up "/<name>", read the miss as
"source gone", and skipped a live file on a transient lookup error —
the silent drop this change is meant to eliminate.

Derive the path via MetadataEventTargetFullPath (the same directory
fallback genProcessFunction uses) and cover both event shapes with
TestEventSupersessionProbe_PathDerivation.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(filersink): retry manifest resolve only for transient errors, bounded when unverifiable

The manifest-resolve retry stopped only when hasSourceNewerVersion proved
the source moved past the replayed version, which wedged the sink in two
cases: incremental sinks use dated target keys that cannot map back to a
source path (supersession never provable), and permanent resolve errors
(corrupt manifest data, bad file ids) fail forever while the source entry
stays live.

Gate the retry instead: keep retrying only transient errors (volume-lookup
races, network interruptions), stop after a few attempts when supersession
cannot be checked, and propagate everything else immediately so the
configured metadata error policy applies (-disableErrorRetry included).
Propagation is lossless: filer.backup's fallback decides with the event's
real source key, and both filer.backup and filer.sync re-deliver the event
(RetryForeverOnError) without advancing the offset.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(filer.backup): make error classifiers nil-safe

isIgnorable404, isSourceLookupError, and isTransientResolveError called
err.Error() without a nil guard. All current call sites pass a non-nil
error, but the guard is free and matches isRetryableNetworkError.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-07-10 01:47:46 -07:00
Chris Lu c1ccbe97dd feat(filer.backup): -initialSnapshot seeds destination from live tree (#9126)
* feat(filer.backup): -initialSnapshot seeds destination from live tree

Replaying the metadata event log on a fresh sync only leaves files that
still exist on the source at replay time: any entry that was created and
later deleted is replayed as a create/delete pair and never materializes
on the destination. Users who wipe the destination and re-run
filer.backup therefore see "only new files" instead of a full backup,
even when -timeAgo=876000h is passed and the subscription genuinely
starts from epoch (ref discussion #8672).

Add a -initialSnapshot opt-in flag: when set on a fresh sync (no prior
checkpoint, -timeAgo unset), walk the live filer tree under -filerPath
via TraverseBfs and seed the destination through sink.CreateEntry, then
persist the walk-start timestamp as the checkpoint and subscribe from
there. Capturing the timestamp before the walk lets the subscription
catch any create/update/delete racing with the walk — sink CreateEntry
is idempotent across the builtin sinks so replay is safe.

Honors existing -filerExcludePaths / -filerExcludeFileNames /
-filerExcludePathPatterns filters and skips /topics/.system/log the
same way the subscription path does.

Also log "starting from <t> (no prior checkpoint)" instead of a
misleading "resuming from 1970-01-01" when the KV has no stored offset.

* fix(filer.backup): guard initialSnapshot counters under TraverseBfs workers

TraverseBfs fans the callback out across 5 worker goroutines, so the
entryCount / byteCount updates and the 5-second progress-log gate in
runInitialSnapshot were racing. Switch the counters to atomic.Int64 and
protect the lastLog check/update with a short-scoped mutex so the heavy
sink.CreateEntry call stays outside the critical section.

Flagged by gemini-code-assist on #9126; verified with go test -race.

* fix(filer.backup): harden initialSnapshot against transient errors and path edge cases

Three review items from CodeRabbit on #9126:

1. getOffset errors no longer leave isFreshSync=true. Before, a transient
   KV read failure would cause runFilerBackup's retry loop to redo the
   full -initialSnapshot walk on every retry. Treat any offset-read
   error as "not fresh" so the snapshot only runs when we've verified
   there really is no prior checkpoint.

2. initialSnapshotTargetKey now normalizes sourcePath to a trailing-
   slash base before stripping the prefix, so edge cases where
   sourceKey equals sourcePath (trailing-slash mismatch or root-entry
   emission) no longer index past the end. Unit tests cover both
   forms.

3. Documented the TraverseBfs-enumerates-excluded-subtrees performance
   characteristic on runInitialSnapshot, since pruning requires a
   separate change to TraverseBfs itself.

* fix(filer.backup): retry setOffset after initialSnapshot to avoid full re-walks

If the snapshot walk finishes but the subsequent setOffset fails, the
retry loop in runFilerBackup will re-enter doFilerBackup with an empty
checkpoint and run the full BFS again — on a multi-million-entry tree
that's hours of wasted work over a 100-byte KV write. Retry the write a
handful of times with exponential backoff before giving up, and log
loudly at the final failure (with snapshotTsNs + sinkId) so operators
recognize the symptom instead of guessing at mysterious repeated walks.

Nitpick raised by CodeRabbit on #9126.

* fix(filer.backup): initialSnapshot ignore404, skew margin, exclude dir-entry itself

Three review items from CodeRabbit on #9126:

1. ignore404Error now threads into runInitialSnapshot. If a file is listed
   by TraverseBfs and then deleted before CreateEntry reads its chunks,
   the follow path already ignores 404s — the snapshot path was aborting
   and triggering a full re-walk. Treat an ignorable 404 as "skip this
   entry, continue."

2. snapshotTsNs now uses `time.Now() - 1min` instead of `time.Now()`.
   Metadata events are stamped server-side, so a fast backup-host clock
   could skip events that fire during or right after the walk. Matches
   the 1-minute margin meta_aggregator.go applies on initial peer
   traversal; duplicate replay is harmless because CreateEntry is
   idempotent.

3. Exclude checks now run against the entry's own full path, not just
   its parent. A walked directory whose full path matches SystemLogDir
   or -filerExcludePaths was being seeded to the destination; only its
   descendants were being skipped. Verified with a manual repro where
   -filerExcludePaths=/data/skipdir now keeps the skipdir entry itself
   off the destination.

* refactor(filer): share destKey helper between buildKey and initialSnapshot

Extract destKey(dataSink, targetPath, sourcePath, sourceKey, mTime) from
buildKey in filer_sync.go. Both the event-log path (buildKey) and the
initialSnapshot walk (initialSnapshotTargetKey) now go through the same
helper, so a walk-seeded file and an event-replayed file always resolve
to the same destination key.

As a bonus, buildKey picks up the defensive trailing-slash normalization
that initialSnapshotTargetKey introduced — no more index-past-end risk
when sourceKey happens to equal sourcePath. Also tightens the mTime
lookup to guard against nil Attributes (caught by an existing test
against buildKey when I first moved the lookup out of the incremental
branch).
2026-04-17 21:21:32 -07:00
Mmx233 ecadeddcbe fix: extend ignore404Error to match 404 Not Found string from S3 sink… (#8741)
* fix: extend ignore404Error to match 404 Not Found string from S3 sink errors

* test: add unit tests for isIgnorable404 error matching

* improve: pre-compute ignorable 404 string and simplify isIgnorable404

* test: replace init() with TestMain for global HTTP client setup
2026-03-23 11:59:34 -07:00