Commit Graph
7 Commits
Author SHA1 Message Date
Chris Lu 3bd218e030 volume: cut idle memory at high volume counts (#10861)
* volume: start a volume's batch write worker on first use

Mounting a volume started a goroutine parked on a 128-slot channel, plus
the 128-entry batch slice it had already allocated. That is around 6.7KB
per volume the server pays whether or not the volume ever takes a write:
7231 bytes per mounted volume, of which 4101 is goroutine stack.

Only a write that asks for fsync ever reaches the worker, and a
remote-tiered or read-only volume never can. Create the channel and its
goroutine on the first such request instead, and let a write arriving
after Destroy fall back to the inline path rather than queue onto a
worker that has gone.

Measured over 20000 mounted volumes: 7231 -> 1269 bytes each.

* volume: update the heartbeat report state in place

Every heartbeat built a second map of what it was about to tell the
master, holding a freshly allocated short information message per volume,
then swapped it in over the old one -- and computed departures through a
third map of the live volume ids. A server holding 2M volumes rebuilt all
three every VolumePulsePeriod for a report that usually says nothing.

Number the heartbeats instead and mark the entry already held with the
pass that found the copy, so a quiet volume costs a map lookup and no
allocation. Departures are the entries a pass did not mark; the live-id
map is now built only when there are some, sized to them.

Measured over 10000 mounted volumes: 436 -> 196 bytes allocated per
volume per heartbeat.

* volume: fill one volume information message per heartbeat, not per volume

The heartbeat built a message for every volume held so it could hash it,
then dropped all but the few it had something to say about. At 2M volumes
that is 2M messages allocated every VolumePulsePeriod to send almost none
of them.

Fill a message the caller supplies instead, and replace it only when the
heartbeat keeps it, so a server with nothing to report fills the same one
all the way through.

Measured over 10000 mounted volumes: 196 -> 4 bytes allocated per volume
per heartbeat, and a heartbeat runs a third faster.

* volume: drop the per-volume trace from the heartbeat's status read

glog.V(4).Infof evaluates its arguments whether or not the verbosity is
on, so every volume boxed its id into a fresh interface slice on every
heartbeat: 759 of the 773 allocations a 1000-volume heartbeat made, for a
line that at this scale would print millions of unreadable rows.

Measured over 1000 mounted volumes: 4776 -> 1792 bytes and 759 -> 14
allocations per heartbeat, which no longer grows with the volume count.

* seaweed-volume: mirror the in-place heartbeat report state

Same change as the Go volume server: number the heartbeats and mark the
entry already held with the pass that found the copy, instead of building
a second map of hashes and swapping it in.

The volume snapshot must leave the reporting state as it found it, so it
keeps asking through changed() while a real heartbeat marks through
record().

* volume: refuse writes to a closed volume instead of dereferencing nil

Close and Destroy leave the needle map and data backend nil, but a caller
that already holds the volume can still reach the write path, where both
are used unguarded: a write racing a volume deletion took the server down.
syncDelete has always checked; syncWrite and the batch worker had not.

Reachable before this series and now also from the inline fallback a
durable write takes when the worker has gone.

* seaweed-volume: guard the report state with one mutex, as Go does

The full-list flag and the generation that answers it have to move
together. Split across separate atomics they cannot: a request landing
between begin's two reads returns full == false with the generation it
just raised, and one landing between commit's read and its clear is
marked answered by a heartbeat that carried no list. Either way the
resend is dropped.

Neither is reachable today -- every caller reaches this through the
store's RwLock, the flag setters under a read lock and the heartbeat
build under a write lock, so they cannot interleave. The type should not
depend on that being true two files away, and Go holds a single mutex
over exactly these fields.

* test: build the servers under test to match the harness's offset size

The mixed Go/Rust suites run both servers against one dataset, so both
have to agree on the offset width. They did not: the harness built Go
with no tags, 4-byte offsets, while the Rust crate defaults to its 5bytes
feature, and the Rust server then refused the .vif the Go server had just
written -- "bytes_offset mismatch: found 4, expected 5".

Build each side to match the offset size the test binary itself was
compiled with, so a plain `go test` and one with -tags 5BytesOffset both
get a matched pair.
2026-08-21 13:04:56 -07:00
9575032b4c volume: forward fsync=true to replicas in ReplicatedWrite (#10805)
* volume: forward fsync=true to replicas in ReplicatedWrite

When a write request carries fsync=true, only the primary volume server
flushed to disk: the replica fan-out URL in ReplicatedWrite only carried
type/ttl/ts/cm, so replicas always wrote without fsync even when the
client explicitly requested a durable write.

Forward the fsync request parameter to the replica volume servers so a
durable write means every replica has flushed to disk, not just the
primary. Replicas without fsync are untouched (zero behavior change).

* storage: flush a durable write inline while stopping

The fsync flag on the write path really selects the async batch worker,
and it was switched off once the store is stopping. So a fsync=true write
landing during the pre-stop drain got acked without ever being flushed -
and now that ReplicatedWrite forwards fsync, that covers replicas too.

Flush it inline instead of queueing it. The drain keeps accepting writes,
which is the whole point of preStopSeconds, and the ack still means the
.dat is on disk. If the fsync fails, the append comes back off the .dat
and the needle map goes back to what it pointed at before, so nothing
resolves to an offset past the truncated end.

* storage: make the store's stopping flag atomic

SetStopping runs on the signal handler goroutine while the write and
vacuum paths read the flag, so every read of it was racy. Nothing about
the shutdown ordering changes; only the flag itself is now safe to read.

* topology: check the errors the replication test was dropping

The mock replica ignored its response write and the mock master ignored
whatever Serve returned, so a broken mock would have shown up as a
confusing timeout rather than a failure. Also drops the explicit listener
close: grpc.Server.Stop already closes the listener it was given.

---------

Co-authored-by: hzsunchao <hzsunchao@corp.netease.com>
Co-authored-by: Chris Lu <chris.lu@gmail.com>
2026-08-18 17:17:50 -07:00
Chris Lu 0ae1fdcad2 volume: reload a remote-tiered volume without re-entering the data lock (#10266)
LoadRemoteFile now takes dataFileAccessLock (so a live tier upload does
not race the heartbeat's DataBackend read). But load() also runs it, and
CommitCompact calls load() while already holding that lock, so reloading
a remote-tiered volume during a compaction commit re-enters the
non-reentrant lock and deadlocks.

Split the locked bodies out: swapDataBackendLocked and loadRemoteFileLocked
assume the caller holds dataFileAccessLock. load() uses loadRemoteFileLocked;
the public LoadRemoteFile keeps taking the lock for the live tier-upload
handler that does not hold it.
2026-07-08 01:27:10 -07:00
Chris Lu 2d2fdeac3d volume: keep tier-uploaded volume reporting to master after volume.tier.upload (#10259)
volume: keep tier-uploaded volume reporting to master

A live volume.tier.upload removes the local .dat and swaps the data
backend to remote, but v.hasRemoteFile was only ever set when a volume
is loaded from disk, so the running volume kept it false. The phantom
.dat guard then saw fileCount>0, !HasRemoteFile, and a missing .dat, and
stopped reporting the volume to the master. The volume vanished from the
topology even though the upload succeeded and the data was in cloud
storage.

Set hasRemoteFile in LoadRemoteFile, the single point where a volume's
backend becomes remote, so it is true both on disk-scan load and after
an in-process tier upload. Route the backend reassignment through
SwapDataBackend so it happens under dataFileAccessLock, closing the old
backend and never racing the heartbeat's concurrent DataBackend read.
Make the field atomic since the heartbeat now reads it concurrently with
the tier-upload handler that writes it.
2026-07-07 23:00:22 -07:00
Chris Lu 1c9039d3ac fix(seaweed-volume): stop EC shard deletion from phantom .dat on restart (#9874)
* fix(seaweed-volume): stop EC shard deletion from phantom .dat on restart

On startup load_existing_volumes() scans .vif/.idx entries (not just
.dat). For distributed EC, a volume's .vif can be mirrored onto a disk
whose .ecx lives on a sibling disk, so the per-disk ecx check is false
and the loader falls through to Volume::new, which always creates the
.dat if missing -> a phantom 8-byte superblock stub. The store-level
prune_incomplete_ec_with_sibling_dat then treats that stub as the
authoritative source and deletes the real EC shards on sibling disks. Go
guards the same case (disk_location.go: 'Without this guard NewVolume
below would create a phantom empty .dat') but only same-disk.

Fix A (root cause): in load_existing_volumes, don't create a .dat during
load. Skip the entry when there is no local .dat AND the .vif does not
reference remote files -- remote-tiered volumes have no local .dat but
must still load via the remote path. Uses the robust check_dat_file_exists
helper so a transient stat error doesn't skip a real volume. New volumes
go through create_volume(). Covers the cross-disk .vif/.ecx split Go's
same-disk hasEcxFile() misses.

Fix B (defense in depth, Go + Rust): when the EC .vif records no source
size (dat_file_size==0), require the sibling .dat to be strictly larger
than a bare superblock, so an empty 8-byte stub can't pass the
credibility gate. Previously it fell back to SUPER_BLOCK_SIZE, which an
8-byte stub exactly meets.

Adds regression tests reproducing the cross-disk lone-.vif phantom and
the 8-byte stub gate; updates an existing prune test to use a real
collection so its .ecx lookup matches the loaders.

* fix(storage): don't create phantom .dat from lone .vif on Go volume load

Mirror Fix A on the Go side. loadExistingVolume scans .vif/.idx entries,
and for distributed EC a .vif can be mirrored onto a disk whose .ecx is
on a sibling disk. The same-disk hasEcxFile() guard does not fire there,
so the loader falls through to NewVolume(createDatIfMissing=true) and
writes an 8-byte phantom .dat, which the sibling-.dat prune then uses to
delete the real EC shards on sibling disks. Skip the entry when there is
no local .dat AND the .vif has no remote file (via MaybeLoadVolumeInfo);
remote-tiered volumes have no local .dat but must still load.

Adds TestLoneVifDoesNotCreatePhantomDat (fails without the guard) and
TestRemoteTier_DiskScanLoadsRemoteOnlyVolume (fails if the guard skips a
remote-only volume).
2026-06-08 22:10:16 -07:00
Chris Lu 9658f309d2 EC bitrot detection: per-shard checksum sidecars (#9761)
* ec: add EC bitrot checksum protobuf

EcBitrotProtection/EcShardChecksums/ChecksumAlgorithm sidecar messages,
copy_ecsum_file and unsafe_ignore_sidecar fields, and a CHECKSUM scrub mode.

* ec: bitrot checksum sidecar format, validation, and per-volume load

Per-shard CRC32C block checksums in an optional <base>.ecsum sidecar with a
self-integrity header; validation, rolling builder, backfill primitive, and
EcVolume load on mount + removal on destroy.

* ec: capture per-shard checksums at encode; verify-and-exclude on rebuild

WriteEcFilesWithContext returns the protection computed inline during encoding.
generateMissingEcFiles verifies present inputs against the sidecar, excludes
corrupt ones, regenerates in place, and re-verifies; fail-closed unless
unsafe_ignore_sidecar, removing all generated outputs on failure.

* ec: read-only checksum scrub with Reed-Solomon arbiter

ChecksumScrub verifies each local shard against the sidecar and reconstructs
flagged shards from the clean shards so stale-sidecar false positives are not
reported. Wired to the gRPC CHECKSUM mode and ec.scrub -mode checksum.

* ec: server-side bitrot sidecar write, copy, cleanup, and opportunistic backfill

Write .ecsum at fresh encode; propagate it with copy_ecsum_file (tolerant);
remove it on full delete and decode; rebuild honors unsafe_ignore_sidecar and
opportunistically backfills a sidecar when all shards are reachable.

* ec: volume server bitrot config flags

-ec.bitrotChecksum (default on) and -ec.bitrotBlockSizeMB (default 16).

* fix(ec_bitrot): bound -ec.bitrotBlockSizeMB before the int64 multiply

Validate the MiB value is in [1, 1024] before multiplying by 1 MiB, so a huge
flag value cannot overflow int64 and slip past the power-of-two check, and a
block size cannot collapse a sidecar to a few oversized blocks.

* fix(ec_bitrot): distribute the .ecsum sidecar from the worker encode path

The worker EC encode wrote the generation-0 sidecar locally but never added it
to shardFiles, so DistributeEcShards never shipped it and the distributed
holders came up unprotected. Append it to shardFiles and map the ecsum shard
type to its extension in the sender so it travels with the shards.

* fix(ec_bitrot): remove orphaned sidecars when the generation is gone

Gate sidecar removal on existingShardCount==0 alone rather than also requiring a
stray .ecx. A sidecar whose shards have all been deleted is orphaned and must be
removed even when no .ecx remains, or it leaks. .ecx/.ecj/.vif removal stays
gated on hasEcxFile as before.

* fix(ec_bitrot): do not fold checksum blocks scanned into TotalFiles

ChecksumScrub's first return is blocks scanned, not files. Discard it so the
scrub response's TotalFiles (a needle/file count) is not inflated by the block
count for CHECKSUM mode.

* test(ec_bitrot): clean up generated .ecsum sidecars in removeGeneratedFiles

* fix(ec_bitrot): reject an oversized sidecar payload before the uint32 cast

The header stores payload_len as a uint32; bound the payload before the
conversion so a pathological manifest cannot truncate the length field and
corrupt the sidecar. A real manifest is a few KB, so this never trips.

* fix(ec_bitrot): cap -ec.bitrotBlockSizeMB at 64 MiB

The block size becomes the per-shard scratch buffer the scrub/backfill path
allocates, so an over-large value (e.g. 1 GiB) is a memory hazard per concurrent
scrub worker. Lower the upper bound from 1024 to 64 MiB.

* fix(ec_bitrot): add -ecUnsafeIgnoreSidecar to weed tool fix -ecx

The -ecx recovery path reconstructs missing shards via RebuildEcFilesWithContext,
which fails closed on a malformed/stale .ecsum. Without an override flag an
operator could not complete the rebuild without manually deleting the sidecar.
Expose -ecUnsafeIgnoreSidecar (default false) and thread it through.

* fix(ec_bitrot): bound sidecar payload with a direct int constant; drop readFull

Guard len(payload) against a plain int constant (1 GiB) before the allocation
instead of a uint64 MaxUint32 compare, so the allocation-size value is provably
bounded (clears the CodeQL overflow alert) and the math import is no longer
needed. Inline os.File.ReadAt with io.EOF handling in verifyShardFileBlocks and
remove the now-redundant readFull helper (os.File.ReadAt fills the slice or
errors).

* test(ec_bitrot): use slices.Contains instead of a hand-rolled containsU32

* refactor(ec): fold the EcFiles WithContext variants into the base functions

RebuildEcFiles now takes the *ECContext directly (nil => derive from .vif as
before) and WriteEcFiles takes it too (nil => default), removing the parallel
RebuildEcFilesWithContext / WriteEcFilesWithContext names. Callers that had an
explicit context drop the WithContext suffix; the default-context callers pass
nil. No behavior change.

* refactor(ec): pass BackgroundECContext instead of nil to Write/RebuildEcFiles

Add a non-nil BackgroundECContext placeholder (analogous to context.Background())
and have callers with no specific layout pass it instead of a nil *ECContext.
WriteEcFiles resolves a zero/background context to the default ratio and
RebuildEcFiles resolves it from the .vif, so behavior is unchanged.

* fix(ec_bitrot): make BackgroundECContext a func; RebuildEcFiles fails closed on bad .vif

- BackgroundECContext is now a function returning a fresh *ECContext, so callers
  cannot mutate a shared singleton or race on it (and it mirrors context.Background,
  which is also a function).
- RebuildEcFiles now propagates the MaybeLoadVolumeInfo error: a present-but-
  unreadable .vif fails closed instead of silently rebuilding with the default
  ratio (which would corrupt a custom-ratio volume). Pass an explicit ctx to override.
2026-05-31 18:52:44 -07:00
Chris Luandgemini-code-assist[bot] 1c0e24f06a fix(balance): don't move remote-tiered volumes; don't fatal on missing .idx (#9335)
* fix(volume): don't fatal on missing .idx for remote-tiered volume

A .vif left behind without its .idx (orphaned by a crashed move, partial
copy, or hand-edit) would trip glog.Fatalf in checkIdxFile and take the
whole volume server down on boot, killing every healthy volume on it
too. For remote-tiered volumes treat it as a per-volume load error so
the server can come up and the operator can clean up the stray .vif.

Refs #9331.

* fix(balance): skip remote-tiered volumes in admin balance detection

The admin/worker balance detector had no equivalent of the shell-side
guard ("does not move volume in remote storage" in
command_volume_balance.go), so it scheduled moves on remote-tiered
volumes. The "move" copies .idx/.vif to the destination and then calls
Volume.Destroy on the source, which calls backendStorage.DeleteFile —
deleting the remote object the destination's new .vif now points at.

Populate HasRemoteCopy on the metrics emitted by both the admin
maintenance scanner and the worker's master poll, then drop those
volumes at the top of Detection.

Fixes #9331.

* Apply suggestion from @gemini-code-assist[bot]

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

* fix(volume): keep remote data on volume-move-driven delete

The on-source delete after a volume move (admin/worker balance and
shell volume.move) ran Volume.Destroy with no way to opt out of the
remote-object cleanup. Volume.Destroy unconditionally calls
backendStorage.DeleteFile for remote-tiered volumes, so a successful
move would copy .idx/.vif to the destination and then nuke the cloud
object the destination's new .vif was already pointing at.

Add VolumeDeleteRequest.keep_remote_data and plumb it through
Store.DeleteVolume / DiskLocation.DeleteVolume / Volume.Destroy. The
balance task and shell volume.move set it to true; the post-tier-upload
cleanup of other replicas and the over-replication trim in
volume.fix.replication also set it to true since the remote object is
still referenced. Other real-delete callers keep the default. The
delete-before-receive path in VolumeCopy also sets it: the inbound copy
carries a .vif that may reference the same cloud object as the
existing volume.

Refs #9331.

* test(storage): in-process remote-tier integration tests

Cover the four operations the user is most likely to run against a
cloud-tiered volume — balance/move, vacuum, EC encode, EC decode — by
registering a local-disk-backed BackendStorage as the "remote" tier and
exercising the real Volume / DiskLocation / EC encoder code paths.

Locks in:
- Destroy(keepRemoteData=true) preserves the remote object (move case)
- Destroy(keepRemoteData=false) deletes it (real-delete case)
- Vacuum/compact on a remote-tier volume never deletes the remote object
- EC encode requires the local .dat (callers must download first)
- EC encode + rebuild round-trips after a tier-down

Tests run in-process and finish in under a second total — no cluster,
binary, or external storage required.

* fix(rust-volume): keep remote data on volume-move-driven delete

Mirror the Go fix in seaweed-volume: plumb keep_remote_data through
grpc volume_delete → Store.delete_volume → DiskLocation.delete_volume
→ Volume.destroy, and skip the s3-tier delete_file call when the flag
is set. The pre-receive cleanup in volume_copy passes true for the
same reason as the Go side: the inbound copy carries a .vif that may
reference the same cloud object as the existing volume.

The Rust loader already warns rather than fataling on a stray .vif
without an .idx (volume.rs load_index_inmemory / load_index_redb), so
no counterpart to the Go fatal-on-missing-idx fix is needed.

Refs #9331.

* fix(volume): preserve remote tier on IO-error eviction; fix EC test target

Two review nits:

- Store.MaybeAddVolumes' periodic cleanup pass deleted IO-errored
  volumes with keepRemoteData=false, so a transient local fault on a
  remote-tiered volume would also nuke the cloud object. Track the
  delete reason via a parallel slice and pass keepRemoteData=v.HasRemoteFile()
  for IO-error evictions; TTL-expired evictions still pass false.

- TestRemoteTier_ECEncodeDecode_AfterDownload deleted shards 0..3 but
  called them "parity" — by the klauspost/reedsolomon convention shards
  0..DataShardsCount-1 are data and DataShardsCount..TotalShardsCount-1
  are parity. Switch the loop to delete the parity range so the
  intent matches the indices.

---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
2026-05-06 15:19:43 -07:00