* 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.
* fix(filer.sync): replicate a rename as create-then-delete, not an in-place update
A rename arrives as a single metadata event carrying both the old and new
entry. The filer sink was routed to UpdateEntry, which looks up the old
path but issues the update against the new parent without changing the
name — and the filer UpdateEntry RPC cannot move an entry. So the rename
was dropped: the old path lingered and the new path never appeared
(same-dir renames rewrote the old name in place).
Route a real move (the sink path changed) through CreateEntry(new) then
DeleteEntry(old) in both the replicator and the filer.sync/backup driver,
the way the other sinks already handle it; reach UpdateEntry only for true
in-place updates. Create before delete so a crash between the two leaves
the entry visible rather than lost.
* fix(filer.sync): derive the rename delete key like the create key, guard the watched root
The rename delete leg rebuilt the old key with a raw util.Join, bypassing the
sink-side key normalization the create leg gets from buildKey — so a rename
could create the new entry and then fail to delete the old one under a
transformed key. Build the old key through buildKey too, and skip the delete
when the moved entry is the watched root itself (where the old key would
resolve to the target root and recursively delete the whole sink tree).
* test(filer.sync): cover the in-place update delete-then-create fallback order
The recording sinks always reported foundExisting, so the fallback that an
in-place update takes when the entry is missing on the sink was never run.
Make it configurable and assert the fallback deletes before it recreates the
same key, in both the replicator and the filer.sync drivers.
* feat(filer.sync): move filer-sink renames natively via AtomicRenameEntry
create-then-delete is unsafe for the filer sink: CreateEntry returns nil
without creating on a transient chunk-copy error, so the paired delete could
remove the only valid destination copy; a directory rename also deleted the
old subtree before descendants were recreated, and left old chunks behind.
Add an optional EntryMover sink capability and implement it on the filer sink
via AtomicRenameEntry — one atomic, metadata-only move that relocates a whole
subtree in a single transaction. Renames prefer it; sinks without a native
move keep create-then-delete. When the old path is already gone (a descendant
the parent rename moved, or one never replicated) MoveEntry creates the new
path instead, re-checking existence with a lookup so a rolled-back move that
left the old entry intact is retried rather than mistaken for gone.
* docs(filer.sync): note entryMissing's gRPC not-found string fallback is deliberate
Chris Lu