9 Commits
Author SHA1 Message Date
Chris Lu 88c873ecd4 ec: uniform shard block layout (#10932)
* ec: uniform shard block layout

An EC volume is striped as 1GiB blocks until less than one row remains, then
1MiB blocks, and consecutive blocks land on different shards. With ec.encode's
-fullPercent 95 against the 30GiB default limit, ~30% of every volume sits in
that 1MiB tail, so a 4MB filer chunk there is five stripes on five servers.

New encodes now use one block per shard, sized ceil(datSize/dataShards) rounded
up to 1MiB and recorded in the .vif (EcShardConfig.block_size, also carried by
the .ecsum manifest). A needle now maps to one shard unless it is larger than
the block or straddles a boundary. The chosen size equals the legacy layout's
padded shard length for every input, so shard sizes, capacity math, and the
shard-size credibility checks are unchanged; only the byte placement moved.

Reads, decode, and scrub resolve the block sizes from the volume's .vif;
absence keeps the legacy interpretation, so existing EC volumes read exactly as
before. Rebuild is layout-agnostic. weed fix -ecx recovers the layout from the
.vif, else the .ecsum sidecar, and with neither de-stripes under both candidate
layouts and keeps the one that indexes more valid needles.

Same change in the Rust volume server, which now also streams the encode in
256KB sub-batches like Go instead of allocating whole blocks, and computes the
large-row count as shardSize/largeBlock to match Go on exact multiples. On a
26MB fixture both encoders produce byte-identical shards, and a Go-written .vif
parses in Rust with the block size intact.

* ec: resolve the rust ecx rebuild through the recorded layout

The Rust rebuild path regenerated a lost .ecx by scanning the logical .dat
through a hand-rolled pure-1MiB striping, which was already wrong for legacy
volumes with large-block rows and is wrong for any uniform volume with a block
past 1MiB. Route the scan through locate_data with the .vif-recorded block
size, the same mapping the read path uses. Also seed the new tests' random
data instead of the deprecated global math/rand.Read.

* ec: fail the Rust ecx rebuild on any shard read error

A read error mid-scan published the entries collected so far as a
successful .ecx, and read_at's byte count was ignored so a legal short
read passed as complete — a truncated or failing shard could produce a
silently incomplete recovery index. Exact-read semantics in
read_from_data_shards, error propagation in the needle walk, and a
truncated-shard regression test.

* ec: fail the mount on an unreadable or malformed vif

Both servers silently fell back to the legacy layout when an existing
.vif could not be read or parsed. Every new encode records a positive
uniform block size there, so the fallback mounted the same shards with
legacy offset math and could return wrong data. Absent stays legal
(legacy volumes predate the sidecar), and a zero-byte stub still reads
as absent (Go's MaybeLoadVolumeInfo convention, now mirrored in Rust);
a present-but-unreadable or malformed .vif fails the mount instead.

* ec: bound the reconstruct fan-out of one needle's intervals

A degraded interval fans out a read to every reachable shard location, each
with a buffer the size of the interval. Reading a needle's intervals in
parallel multiplied that by the interval concurrency: a needle spanning 8
blocks could hold 8 x MaxShardCount remote reads and buffers at once, where
the sequential version peaked at MaxShardCount. Give each needle a single
reconstruct budget its intervals share, held for the buffer's lifetime, so
separate reads stay independent but one read cannot multiply its own
fan-out.

* ec: drop the duplicated shard-size formula

calculateExpectedShardSize reimplemented the padding rule that
UniformBlockSize already owns — TestUniformBlockSizeMatchesLegacyShardSize
asserts the two agree for every input — so a change to the rule would have
had to be made in both. Defer to the helper, keeping the historic answer for
an empty .dat.

* ec: resolve the shard block layout from whatever records it

Four places still answered the layout question by inference when a record of
it was available, or accepted an answer that was not one:

- A mount with no .vif defaulted to the legacy layout; the bitrot sidecar
  records the same config at encode time, so take it when present, as
  weed fix -ecx already does. The vif itself is now parsed once per mount
  rather than twice.
- The Rust ecx rebuild derived its row count from the padded shard extent,
  which under the legacy layout reads a shard that is an exact large-block
  multiple as one row too many. Pass the encode-time .dat size from the .vif
  and keep the extent as the fallback.
- weed fix -ecx read the block size outside the EC-config guard (collapsing
  the unknown sentinel into a definitive legacy), only wrote the recovered
  layout back when the .vif was absent rather than unusable, and broke a
  scan tie by candidate order instead of the documented reach.
- The uniform layout tripped writeDatFile's large-block ambiguity guard,
  which cannot apply when the large and small blocks are the same size.

* ec: give the index-recovery tests a parseable vif

The fixtures wrote the literal bytes "volinfo" as the source .vif and the
recovery copies it verbatim, so the receiving server then mounted the volume
from a .vif it could not parse. That used to pass by silently defaulting to
the legacy layout; a mount now refuses a vif it cannot read, which is what
the tests were exercising all along without meaning to.

* ec: validate the layout a vif records, not just its syntax

Review follow-ups on the mount-strictness change:

- A .vif can parse and still record a block size no encoder could have
  produced (negative, or not a whole number of small blocks). Both servers
  took it and mapped every read through it. ValidateBlockSize / the Rust
  mirror now refuse the mount, the same way an unparseable vif does; 0 stays
  valid as the legacy two-tier layout.
- The bitrot-sidecar fallback accepted parity_shards == 0 and summed the
  counts in their own width, so values near the ceiling wrapped past the
  MaxShardCount bound. Require both counts and sum in a wider type.
- weed fix -ecx treated a config with only DataShards > 0 as usable, so a
  half-written .vif suppressed the recovery paths AND survived the rewrite.
  Require a complete, in-range config before trusting it.
- Returning the vif-load error left the .ecx and .ecj descriptors open;
  repeated mount attempts on malformed metadata could exhaust them.

* ec: refuse to act on a layout the metadata does not establish

- The worker encode only logged a failed .vif write and skipped it in the
  distribution set, and treated the .ecsum write as best-effort. A worker
  whose disk filled after the much larger shards landed could still
  distribute, mount, verify shard inventory, and delete the source replicas —
  leaving holders with shards whose geometry nothing records. Both writes and
  both inclusions are encode success conditions now.
- A generation-matching .ecsum that disagreed with the .vif geometry only
  disabled checksums in Go, and in Rust was not compared at all, so
  protection stayed On while reads used the other layout. Both files record
  the layout their generation was encoded with, so a disagreement now fails
  the mount.

* ec: reject an invalid recorded block size in weed fix -ecx

A .vif with valid shard counts but a negative or unaligned block size was
marked usable: a positive invalid value pinned the scan to a geometry that
de-stripes to garbage, and a negative one ran the dual scan but left the
invalid .vif in place afterwards. Validate it with the same rule the mount
applies, and when it fails leave the layout unknown so the scan recovers it
and the file is rewritten.

* ec: validate the sidecar layout weed fix -ecx recovers from

The .ecsum fallback was taken on DataShards > 0 alone, so a CRC-valid
sidecar carrying the wrong generation, an incomplete ratio, or an unaligned
block size would pin the reconstruction to one incorrect uniform-layout
candidate instead of letting the dual scan decide. Require generation 0, a
complete in-range ratio, and a valid block size; anything less leaves the
layout unknown, which is the answer that still recovers by scanning.

* ec: let only a genuinely absent sidecar choose the legacy layout

With no .vif the bitrot sidecar is the only record of a volume's layout, and
the mount fallback read a failed load, an unusable config, or a sidecar
stamped for another generation as "assume legacy". A uniform generation-0
volume could therefore mount with legacy or another generation's geometry and
answer reads with the wrong bytes. Present-but-unusable now fails the mount;
only actual absence keeps the legacy defaults. Shared as
EcShardConfigFromSidecar so every caller reads the sidecar the same way.

* ec: treat a recorded-but-impossible layout as corruption, not as legacy

- A .vif whose ecShardConfig is PRESENT but records an impossible ratio was
  answered with the default 10+4 and the legacy block layout, in both
  languages. That reads a uniform volume's shards at the wrong offsets and
  returns the wrong bytes. Only an entirely absent config still means "this
  predates the record"; a present one that cannot be true fails the mount.
- The shard-count bound summed two uint32 counts as int, which wraps on a
  32-bit build: 0x7fffffff + 0x7fffffff lands at -2 and slips under
  MaxShardCount. ValidEcShardCounts sums in uint64, and every EC call site
  that checked a recorded ratio now goes through it.

* ec: rebuild on the geometry the sidecar records, and flag it when it disagrees

The rebuild RPC passes BackgroundECContext, so RebuildEcFiles resolves the
layout itself — and it resolved a missing or invalid .vif to the default 10+4
with the legacy block size. Two consequences: a 12+4 volume was reconstructed
through a 10+4 matrix, which produces wrong bytes and never regenerates
shards 14-15; and the chosen geometry then contradicted a valid uniform
sidecar, which loadRebuildSidecar reported as BitrotOff — silently skipping
the input and regenerated-shard checksum checks precisely when the volume had
already lost its metadata.

The layout now resolves from the bitrot sidecar (found across the server's
disks, not just beside the base name) before falling back to the defaults,
and a present-but-impossible ratio fails instead of being replaced. A sidecar
that contradicts the chosen geometry is BitrotInvalid, which the existing
unsafeIgnoreSidecar override still lets an operator push past.

* ec: let the Rust rebuild read metadata off a sibling disk

read_ec_shard_config searches only the location the rebuild writes into, so a
volume whose .vif or generation-0 .ecsum sits on another of the server's
disks resolved to the default 10+4 with the legacy block layout — the Rust
half of the geometry-guessing the Go rebuild just stopped doing. It then
reconstructs a custom-ratio or uniform volume through the wrong
Reed-Solomon matrix and de-striping geometry.

The rebuild now looks for the .vif in its own location and then each sibling,
falls back to the generation-0 sidecar wherever that lives, and only defaults
when neither exists anywhere. The encode-time .dat size the ecx rebuild needs
is resolved the same way.

* ec: resolve a rebuild's vif from every directory that may hold it

RebuildEcFiles probed only <data-base>.vif. The caller knows the selected
location's index directory and the sibling locations, but passed neither for
metadata: additionalDirs carried shard directories only, and were searched
for shards and the checksum sidecar. A split -dir/-dir.idx layout, or a disk
holding only shards, therefore resolved a pre-sidecar custom-ratio volume to
10+4 and reconstructed through the wrong matrix — never regenerating shards
14-15.

The caller now hands over the index and sibling directories, and the resolver
probes the vif across all of them, matching what the Rust resolver already
does for both the vif and the sidecar.

* ec: make every rebuild consumer agree on the layout it resolved

- The post-rebuild bitrot backfill re-derived the geometry from this
  directory's .vif alone and dropped the block size entirely, so a rebuild
  that resolved its layout from a sibling, the sidecar, or a uniform vif wrote
  a manifest describing a DIFFERENT layout — one later mounts reject, or that
  covers only the default shard count. The layout is resolved once now,
  through an exported ResolveRebuildECContext, and the rebuild and the
  backfill share that answer.
- The Rust rebuild collected only each location's data directory, so a
  sibling's INDEX directory — where a split -dir/-dir.idx layout keeps
  .ecx/.ecj/.vif — was never probed, and a custom-ratio volume still resolved
  to 10+4 with the legacy layout. Both directories of every location are
  carried now, deduped against the rebuild's own.
- A shard delivery can bring the checksum manifest with it, but the receive
  path only writes the file: a server that already had the volume mounted kept
  its resolved protection state (off) until a remount. The mount RPC
  re-resolves it once the shards it describes have been added.

* ec: cover the rebuild's directory search with tests

Reviewers flagged the sibling index directory twice, and the fix that
closed it had no test of its own: the assembly sat inline in the rebuild
handler, reachable only through a gRPC call against a populated store.
Lifting it into rebuildSearchDirs / select_rebuild_location makes the
rule assertable — a sibling contributes BOTH its data and its index
directory, a shared index directory is listed once, and the rebuild's own
data directory never repeats.

Writing the Rust cases surfaced that the two implementations do not agree
on where the rebuild's own index directory belongs, and both are right:
Go's resolver takes a single directory list, so that directory has to be
inside it, while Rust's takes the rebuild's data and index directories as
their own arguments and would search them twice. The tests now state
which contract each side is holding to, so neither drifts into the
other's shape.

Pure refactor otherwise; no behaviour change.

* ec: search the index directory for the layout sidecar

The Rust resolver looked for the generation-0 .ecsum in the rebuild's
data directory and the sibling list, but not in the rebuild's own index
directory — while the .vif lookup directly above it did, and Go's
findBitrotSidecar has always checked both bases. On a split -dir/-dir.idx
location that directory is where the metadata lives, and callers leave it
out of the sibling list precisely because it is passed here separately,
so nothing searched it.

With no .vif anywhere the sidecar is the only surviving record of the
layout. Missing it resolved a 12+4 uniform volume to 10+4 with the legacy
striping — the test added here fails with (10, 4, 0) against the old
code — and the rebuild then reconstructs through the wrong matrix and
writes .ecx offsets that no reader can follow.

* ec: let the rebuild see its own index directory

The Rust rebuild takes a single flat directory list — the shape Go's
RebuildEcFiles uses — so it cannot be handed the rebuild location's index
directory separately the way the layout resolvers are, and the handler
was passing the sibling list, which deliberately omits exactly that
directory. On a split -dir/-dir.idx location that is where .ecx and .vif
live, so the shard and index lookups could not see them.

Go has always carried that directory in additionalDirs; this lines the
two call sites up.

* ec: let a config-free vif fall through to the layout sidecar

A .vif that carries no ecShardConfig answers nothing about the layout, so
it is no more informative than an absent one — but both trees treated its
mere existence as the end of the search. Go went straight to the 10+4
legacy defaults without consulting the sidecar at all; Rust returned
whatever ec_shard_config_from could make of a single directory. A 12+4
uniform volume with a legacy config-free vif therefore resolved as 10+4
legacy, and every read landed at the wrong shard offset.

The sidecar lookup was also single-directory on both sides, while a split
-dir/-dir.idx layout keeps .vif and .ecsum with the INDEX. Go's
findBitrotSidecar has always taken both bases; the callers here passed
only the data base, and the Rust bitrot resolver derived its path from
the data base alone. Rust's layout resolver now takes a candidate
directory list — data, index, then any siblings — and searches all of it,
which also removes the early return that made the vif's presence
decisive.

load_vif_info_across_dirs reported `dir` even when load_vif_info had
found the vif in `dir_idx`. Nothing reads that field today, so this
changes no behaviour; it stops the next caller that resolves the rest of
the volume's metadata against the answer from being sent to a disk
holding none of it.

Absence stays legal throughout: a volume with neither record is genuinely
legacy. Present-but-unusable still fails the mount, now in the
config-free-vif branch too.

* ec: activate a delivered sidecar on every per-disk runtime

A vid mounts as one EcVolume per disk, each with its own resolved
protection state, but the post-delivery reload used the first-match
lookup and so touched exactly one of them. The siblings kept reporting no
protection until a remount — and since shard distribution deduplicates
the metadata files onto the first target disk for a node, the runtime
that got the .ecsum is not necessarily the one the lookup returns.

Iterate every runtime instead, via a new FindAllEcVolumes and its Rust
mut equivalent. Combined with each runtime now resolving its sidecar
against its index directory as well as its data directory, a server
sharing one -dir.idx across its disks activates all of them from the
single delivered copy.

The Rust volume server had no post-mount reload at all; it gets one here,
matching Go.

* ec: resolve the delivered sidecar across every EC metadata directory

Reloading every per-disk runtime, added last round, did not by itself
make the delivered manifest reachable. Startup mirroring copies
.ecx/.ecj/.vif to every shard-bearing disk so each mounts
self-contained, but deliberately not .ecsum, and a repair delivers
exactly one copy. Each runtime was resolving against its own two
directories, so every sibling of the disk that received the file kept
reporting no protection however often it reloaded.

Resolve one authoritative copy across every EC metadata directory
instead of duplicating the file. Mirroring .ecsum would have to keep
pace with a file that is rewritten as shards are repaired, and would not
help the reported case at all: the delivery happens at runtime, and
mirroring only runs at startup.

The regression test pins both halves — a reload restricted to the
volume's own directories still finds nothing, and the same reload
given the server's metadata directories turns protection on.

* ec: ask every directory before writing a TOFU baseline

After a rebuild the opportunistic backfill asks whether this volume
already has a checksum manifest, and answered from the data base alone.
A split -dir/-dir.idx layout keeps the sidecar with the index, and a
multi-disk server may keep it on a sibling, so an existing manifest read
as absent.

The consequence is worse than a missed read. On a false "no" the backfill
writes a fresh sidecar at the data base from whatever the shards say right
now — and the data base is the first candidate every resolver checks, so
that TOFU baseline shadows the real manifest rather than sitting beside
it. A shard that was silently corrupt gets blessed, and the record that
would have caught it stops being consulted.

FindBitrotSidecar exports the search the package already used internally,
so the question is asked of the data base, the index base and the sibling
disks — the same candidates the rebuild resolves its layout from.

* ec: refuse a shard block size no encoder could have produced

weed fix -ecx derived one from the raw shard extent, so a truncated or
partially copied shard wrote a .vif that NewEcVolume then permanently
refuses — the volume the tool was run to rescue could never mount again.
An extent that is not a whole number of small blocks cannot have come
from a uniform encode, so it is no longer offered as a candidate, and
nothing unvalidated reaches the .vif.

Claude-Session: https://claude.ai/code/session_011FRRoNKBiGbH58rs2AQyA7

* ec: derive the .vif's dat size and block size from one measurement

VolumeEcShardsGenerate stat'ed the .dat before the encode while
WriteEcFiles stat'ed it again to size the blocks. A write landing
between the two produced a .vif whose own two fields describe different
files. WriteEcFiles now leaves both on the context, and fills a
placeholder context in place so the caller can read them back.

Claude-Session: https://claude.ai/code/session_011FRRoNKBiGbH58rs2AQyA7

* ec: keep the source volume until every holder serves its shard layout

The uniform layout rides in a .vif field older volume servers never
knew: they discard it, mount the shards as legacy and return wrong bytes
with nothing erroring, and the shard files are the same length either
way so no other check notices. The upgrade order lived only in the
release note. VolumeEcShardsInfo now reports the block size the holder
actually serves, in both the Go and Rust servers, and the pre-delete
verification refuses to drop the source unless every reachable holder
echoes the one the shards were encoded with — while a rollback still
exists. A server that predates the field answers 0, which is the
negative answer.

Claude-Session: https://claude.ai/code/session_011FRRoNKBiGbH58rs2AQyA7

* ec: drop the rebuild's dead block-size parameters

generateMissingEcFiles never reads largeBlockSize/smallBlockSize —
Reed-Solomon reconstruction is layout-agnostic — so passing the legacy
constants only advertised a layout the rebuild does not use. Also move
UniformBlockSize's doc off ValidateBlockSize.

Claude-Session: https://claude.ai/code/session_011FRRoNKBiGbH58rs2AQyA7

* ec: warn about EC defaults only when the mount used them

The "vif file not found, using defaults" warning fired even after the
bitrot sidecar supplied a non-default layout, sending anyone triaging
wrong bytes after the legacy layout the volume never mounted on.

Claude-Session: https://claude.ai/code/session_011FRRoNKBiGbH58rs2AQyA7

* ec: stat the distributed bitrot sidecar once

The strict check re-stat'ed the file immediately before the stat that
already gates inclusion, and a failed sidecar write now fails the encode
outright, so the first could only fire on a deletion between the two
lines.

Claude-Session: https://claude.ai/code/session_011FRRoNKBiGbH58rs2AQyA7

* ec: say what the reconstruct budget actually bounds

A shard's buffer stays in bufs until its interval reconstructs, which is
after the read that filled it released its permit, so the semaphore
bounds round trips in flight and not retained bytes. Peak memory is the
intervals reconstructing at once times the shards each reaches times the
interval size.

Claude-Session: https://claude.ai/code/session_011FRRoNKBiGbH58rs2AQyA7

* test: let the fake volume server report its delivered EC layout

The pre-delete verification now asks each holder which shard block
layout it serves, and a fake that always answered "unset" looked exactly
like a volume server too old to know the field. Distribution ships the
.vif to every holder alongside its shards, so read the layout back out
of it as a real holder does.

Claude-Session: https://claude.ai/code/session_011FRRoNKBiGbH58rs2AQyA7
2026-08-28 20:46:59 -07:00
Chris Lu 94f8e2caf9 EC: handle zero-sized shard files uniformly (moves, rebuilds, startup cleanup) (#10753)
* volume_move: treat zero-sized EC shards as absent in move verification

A zero-sized shard file is residue of a failed operation (issue 10730),
not a shard - but VerifyEcShards only checked presence, so a copy that
landed as an empty file passed verification and the source was deleted
behind it. Size zero now reads as absent, with a distinct error naming
the zero-sized shard so the operator can tell a broken copy from a
missing one.

* storage: exclude zero-sized EC shards from rebuilds and clean up stale ones

The reproducer in issue 10730: a zero-sized shard file left by a failed
operation was selected as a Reed-Solomon input and failed the whole
rebuild with an input size mismatch, because input discovery checked
existence, not substance.

- RebuildEcFiles treats a zero-sized shard file as missing and
  regenerates over it in place (the reclassified-corrupt path: temp
  file beside the residue, atomic rename).
- The startup/rescan shard loader, which always skipped zero-sized
  files, now deletes them once they are older than an hour - young
  enough files can be an in-flight copy's just-created file, since the
  same scan runs from LoadNewVolumes while serving.

Regression tests: a rebuild with one emptied shard regenerates it
byte-identical; the loader deletes a stale zero-sized shard and leaves
a fresh one alone.

* storage: age-check each zero-shard cleanup candidate individually

The shard scan merges the data and idx directory listings, so the
age-checked entry and a deletion candidate can be different files
sharing one name - a stale zero-sized file in one directory next to a
fresh same-named file in the other (possibly an in-flight copy's
just-created one) could get the fresh file deleted. Each candidate's
own modification time now decides, both directories are handled in one
pass, and the split-directory case is pinned by a test.
2026-08-13 21:38:22 -07:00
Chris Lu 5a54beac80 EC decode: read shards with the encode-time block layout (#10385)
* erasure_coding: WriteDatFile takes the encode-time dat size for the shard block layout

* volume server: derive EC decode layout from the encode-time dat size, not the live extent

* erasure_coding: test decode after tail deletions shrink the live extent below a large-block row

* seaweed-volume: write_dat_file_from_shards takes the encode-time dat size for the shard block layout

* seaweed-volume: derive EC decode layout from the encode-time dat size, not the live extent

* seaweed-volume: test decode after tail deletions shrink the live extent below a large-block row

* erasure_coding: reject decoding with no data shards

* worker: record the encode-time dat size in the .vif

* erasure_coding: fall back to the shard-derived layout only when the encode-time dat size is missing

* erasure_coding: reject an ambiguous shard-derived block layout

* seaweed-volume: fall back to the shard-derived layout only when the encode-time dat size is missing

* seaweed-volume: reject an ambiguous shard-derived block layout
2026-07-21 08:59:14 -07:00
qzhello 1d8a6e832c fix(ec): detect truncated .ecx instead of treating it as clean EOF (#10217) 2026-07-03 11:18:46 -07:00
Chris Lu 1e858d8af0 fix(ec): make ec.decode write-path crash-safe and atomic (#9949)
* fix(ec): check decode .idx writes and fsync decoded .dat/.idx

WriteIdxFileFromEcIndex silently dropped io.Copy and Write errors, so a
short or failed write of the reconstructed .idx went unnoticed and the
caller proceeded to delete the source EC shards. Propagate those errors.

Also fsync the decoded .dat and .idx before returning, so the bytes are
durable before the shards that produced them are removed cluster-wide.
Mirror the .idx fsync into the Rust volume server (its .dat already
syncs and its writes already propagate errors).

* fix(ec): publish decoded .dat/.idx atomically via temp file and rename

WriteDatFile and WriteIdxFileFromEcIndex wrote in place at the final
name with O_TRUNC. A crash mid-write left a truncated .dat/.idx at the
final name beside the still-present EC shards; on restart that partial
file could be mounted as the live volume even though the shards held the
real data. Write to a .tmp file, fsync it, then rename into place and
fsync the directory, so the final name is only ever absent or complete.
A failed decode removes its own temp file rather than leaking it.

Add util.FsyncDir as the shared directory-fsync primitive and reuse the
Rust volume server's fsync_dir for the mirrored change.

* fix(ec): propagate .ecj read errors in the Rust decoder

Path::exists returned false for any error (permission denied, transient
IO), silently skipping the deletion journal and resurrecting deleted
needles as live. Read the journal directly and treat only NotFound as
absent, propagating other errors. The Go decoder already behaves this
way (FileExists returns false only for IsNotExist, then the open
surfaces other errors).

* fix(ec): remove rename destination on Windows in the Rust decoder publish

std::fs::rename does not replace an existing file on every Windows
version. Remove the destination first under a Windows guard before the
atomic publish rename, matching the compaction commit path.
2026-06-13 21:26:07 -07:00
Chris Lu 300e906330 admin: report file and delete counts for EC volumes (#9060)
* admin: report file and delete counts for EC volumes

The admin bucket size fix (#9058) left object counts at zero for
EC-encoded data because VolumeEcShardInformationMessage carried no file
count. Billing/monitoring dashboards therefore still under-report
objects once a bucket is EC-encoded.

Thread file_count and delete_count end-to-end:

- Add file_count/delete_count to VolumeEcShardInformationMessage (proto
  fields 8 and 9) and regenerate master_pb.
- Compute them lazily on volume servers by walking the .ecx index once
  per EcVolume, cache on the struct, and keep the cache in sync inside
  DeleteNeedleFromEcx (distinguishing live vs already-tombstoned
  entries so idempotent deletes do not drift the counts).
- Populate the new proto fields from EcVolume.ToVolumeEcShardInformationMessage
  and carry them through the master-side EcVolumeInfo / topology sync.
- Aggregate in admin collectCollectionStats, deduping per volume id:
  every node holding shards of an EC volume reports the same counts, so
  summing across nodes would otherwise multiply the object count by the
  number of shard holders.

Regression tests cover the initial .ecx walk, live/tombstoned delete
bookkeeping (including idempotent and missing-key cases), and the admin
dedup path for an EC volume reported by multiple nodes.

* ec: include .ecj journal in EcVolume delete count

The initial delete count only reflected .ecx tombstones, missing any
needle that was journaled in .ecj but not yet folded into .ecx — e.g.
on partial recovery. Expand initCountsLocked to take the union of
.ecx tombstones and .ecj journal entries, deduped by needle id, so:

  - an id that is both tombstoned in .ecx and listed in .ecj counts once
  - a duplicate .ecj entry counts once
  - an .ecj id with a live .ecx entry is counted as deleted (not live)
  - an .ecj id with no matching .ecx entry is still counted

Covered by TestEcVolumeFileAndDeleteCountEcjUnion.

* ec: report delete count authoritatively and tombstone once per delete

Address two issues with the previous EcVolume file/delete count work:

1. The delete count was computed lazily on first heartbeat and mixed
   in a .ecj-union fallback to "recover" partial state. That diverged
   from how regular volumes report counts (always live from the needle
   map) and had drift cases when .ecj got reconciled. Replace with an
   eager walk of .ecx at NewEcVolume time, maintained incrementally on
   every DeleteNeedleFromEcx call. Semantics now match needle_map_metric:
   FileCount is the total number of needles ever recorded in .ecx
   (live + tombstoned), DeleteCount is the tombstones — so live =
   FileCount - DeleteCount. Drop the .ecj-union logic entirely.

2. A single EC needle delete fanned out to every node holding a replica
   of the primary data shard and called DeleteNeedleFromEcx on each,
   which inflated the per-volume delete total by the replica factor.
   Rewrite doDeleteNeedleFromRemoteEcShardServers to try replicas in
   order and stop at the first success (one tombstone per delete), and
   only fall back to other shards when the primary shard has no home
   (ErrEcShardMissing sentinel), not on transient RPC errors.

Admin aggregation now folds EC counts correctly: FileCount is deduped
per volume id (every shard holder has an identical .ecx) and DeleteCount
is summed across nodes (each delete tombstones exactly one node). Live
object count = deduped FileCount - summed DeleteCount.

Tests updated to match the new semantics:
  - EC volume counts seed FileCount as total .ecx entries (live +
    tombstoned), DeleteCount as tombstones.
  - DeleteNeedleFromEcx keeps FileCount constant and increments
    DeleteCount only on live->tombstone transitions.
  - Admin dedup test uses distinct per-node delete counts (5 + 3 + 2)
    to prove they're summed, while FileCount=100 is applied once.

* ec: test fixture uses real vid; admin warns on skewed ec counts

- writeFixture now builds the .ecx/.ecj/.ec00/.vif filenames from the
  actual vid passed in, instead of hardcoding "_1". The existing tests
  all use vid=1 so behaviour is unchanged, but the helper no longer
  silently diverges from its documented parameter.
- collectCollectionStats logs a glog warning when an EC volume's summed
  delete count exceeds its deduped file count, surfacing the anomaly
  (stale heartbeat, counter drift, etc.) instead of silently dropping
  the volume from the object count.

* ec: derive file/delete counts from .ecx/.ecj file sizes

seedCountsFromEcx walked the full .ecx index at volume load, which is
wasted work: .ecx has fixed-size entries (NeedleMapEntrySize) and .ecj
has fixed-size deletion records (NeedleIdSize), so both counts are pure
file-size arithmetic.

  fileCount   = ecxFileSize / NeedleMapEntrySize
  deleteCount = ecjFileSize / NeedleIdSize

Rip out the cached counters, countsLock, seedCountsFromEcx, and the
recordDelete helper. Track ecjFileSize directly on the EcVolume struct,
seed it from Stat() at load, and bump it on every successful .ecj append
inside DeleteNeedleFromEcx under ecjFileAccessLock. Skip the .ecj write
entirely when the needle is already tombstoned so the derived delete
count stays idempotent on repeat deletes. Heartbeats now compute counts
in O(1).

Tests updated: the initial fixture pre-populates .ecj with two ids to
verify the file-size derivation end-to-end, and the delete test keeps
its idempotent-re-delete / missing-needle invariants (unchanged
externally, now enforced by the early return rather than a cache guard).

* ec: sync Rust volume server with Go file/delete count semantics

Mirror the Go-side EC file/delete count work in the Rust volume server
so mixed Go/Rust clusters report consistent bucket object counts in
the admin dashboard.

- Add file_count (8) and delete_count (9) to the Rust copy of
  VolumeEcShardInformationMessage (seaweed-volume/proto/master.proto).
- EcVolume gains ecj_file_size, seeded from the journal's metadata on
  open and bumped inside journal_delete on every successful append.
- file_and_delete_count() returns counts derived in O(1) from
  ecx_file_size / NEEDLE_MAP_ENTRY_SIZE and
  ecj_file_size / NEEDLE_ID_SIZE, matching Go's FileAndDeleteCount.
- to_volume_ec_shard_information_messages populates the new proto
  fields instead of defaulting them to zero.
- mark_needle_deleted_in_ecx now returns a DeleteOutcome enum
  (NotFound / AlreadyDeleted / Tombstoned) so journal_delete can skip
  both the .ecj append and the size bump when the needle is missing
  or already tombstoned, keeping the derived delete_count idempotent
  on repeat or no-op deletes.
- Rust's EcVolume::new no longer replays .ecj into .ecx on load. Go's
  RebuildEcxFile is only called from specific decode/rebuild gRPC
  handlers, not on volume open, and replaying on load was hiding the
  deletion journal from the new file-size-derived delete counter.
  rebuild_ecx_from_journal is kept as dead_code for future decode
  paths that may want the same replay semantics.

Also clean up the Go FileAndDeleteCount to drop unnecessary runtime
guards against zero constants — NeedleMapEntrySize and NeedleIdSize
are compile-time non-zero.

test_ec_volume_journal updated to pre-populate the .ecx with the
needles it deletes, and extended to verify that repeat and
missing-id deletes do not drift the derived counts.

* ec: document enterprise-reserved proto field range on ec shard info

Both OSS master.proto copies now note that fields 10-19 are reserved
for future upstream additions while 20+ are owned by the enterprise
fork. Enterprise already pins data_shards/parity_shards at 20/21, so
keeping OSS additions inside 8-19 avoids wire-level collisions for
mixed deployments.

* ec(rust): resolve .ecx/.ecj helpers from ecx_actual_dir

ecx_file_name() and ecj_file_name() resolved from self.dir_idx, but
new() opens the actual files from ecx_actual_dir (which may fall back
to the data dir when the idx dir does not contain the index). After a
fallback, read_deleted_needles() and rebuild_ecx_from_journal() would
read/rebuild the wrong (nonexistent) path while heartbeats reported
counts from the file actually in use — silently dropping deletes.

Point idx_base_name() at ecx_actual_dir, which is initialized to
dir_idx and only diverges after a successful fallback, so every call
site agrees with the file new() has open. The pre-fallback call in
new() (line 142) still returns the dir_idx path because
ecx_actual_dir == dir_idx at that point.

Update the destroy() sweep to build the dir_idx cleanup paths
explicitly instead of leaning on the helpers, so post-fallback stale
files in the idx dir are still removed.

* ec: reset ecj size after rebuild; rollback ecx tombstone on ecj failure

Two EC delete-count correctness fixes applied symmetrically to Go and
Rust volume servers.

1. rebuild_ecx_from_journal (Rust) now sets ecj_file_size = 0 after
   recreating the empty journal, matching the on-disk truth.
   Previously the cached size still reflected the pre-rebuild journal
   and file_and_delete_count() would keep reporting stale delete
   counts. The Go side has no equivalent bug because RebuildEcxFile
   runs in an offline helper that does not touch an EcVolume struct.

2. DeleteNeedleFromEcx / journal_delete used to tombstone the .ecx
   entry before writing the .ecj record. If the .ecj append then
   failed, the needle was permanently marked deleted but the
   heartbeat-reported delete_count never advanced (it is derived from
   .ecj file size), and a retry would see AlreadyDeleted and early-
   return, leaving the drift permanent.

   Both languages now capture the entry's file offset and original
   size bytes during the mark step, attempt the .ecj append, and on
   failure roll the .ecx tombstone back by writing the original size
   bytes at the known offset. A rollback that itself errors is
   logged (glog / tracing) but cannot re-sync the files — this is
   the same failure mode a double disk error would produce, and is
   unavoidable without a full on-disk transaction log.

Go: wrap MarkNeedleDeleted in a closure that captures the file
offset into an outer variable, then pass the offset + oldSize to the
new rollbackEcxTombstone helper on .ecj seek/write errors.

Rust: DeleteOutcome::Tombstoned now carries the size_offset and a
[u8; SIZE_SIZE] copy of the pre-tombstone size field. journal_delete
destructures on Tombstoned and calls restore_ecx_size on .ecj append
failure.

* test(ec): widen admin /health wait to 180s for cold CI

TestEcEndToEnd starts master, 14 volume servers, filer, 2 workers and
admin in sequence, then waited only 60s for admin's HTTP server to come
up. On cold GitHub runners the tail of the earlier subprocess startups
eats most of that budget and the wait occasionally times out (last hit
on run 24374773031). The local fast path is still ~20s total, so the
bump only extends the timeout ceiling, not the happy path.

* test(ec): fork volume servers in parallel in TestEcEndToEnd

startWeed is non-blocking (just cmd.Start()), so the per-process fork +
mkdir + log-file-open overhead for 14 volume servers was serialized for
no reason. On cold CI disks that overhead stacks up and eats into the
subsequent admin /health wait, which is how run 24374773031 flaked.

Wrap the volume-server loop in a sync.WaitGroup and guard runningCmds
with a mutex so concurrent appends are safe. startWeed still calls
t.Fatalf on failure, which is fine from a goroutine for a fatal test
abort; the fail-fast isn't something we rely on for precise ordering.

* ec: fsync ecx before ecj, truncate on failure, harden rebuild

Four correctness fixes covering both volume servers.

1. Durability ordering (Go + Rust). After marking the .ecx tombstone
   we now fsync .ecx before touching .ecj, so a crash between the two
   files cannot leave the journal with an entry for a needle whose
   tombstone is still sitting in page cache. Once the fsync returns,
   the tombstone is the source of truth: reads see "deleted",
   delete_count may under-count by one (benign, idempotent retries)
   but never over-reports. If the fsync itself fails we restore the
   original size bytes and surface the error. The .ecj append is then
   followed by its own Sync so the reported delete_count matches the
   on-disk journal once the write returns.

2. .ecj truncation on append failure. write_all may have extended the
   journal on disk before sync_all / Sync errors out, leaving the
   cached ecj_file_size out of sync with the physical length and
   drifting delete_count permanently after restart. Both languages
   now capture the pre-append size, truncate the file back via
   set_len / Truncate on any write or sync failure, and only then
   restore the .ecx tombstone. Truncation errors are logged — same-fd
   length resets cannot realistically fail — but cannot themselves
   re-sync the files.

3. Atomic rebuild_ecx_from_journal (Rust, dead code today but wired
   up on any future decode path). Previously a failed
   mark_needle_deleted_in_ecx call was swallowed with `let _ = ...`
   and the journal was still removed, silently losing tombstones.
   We now bubble up any non-NotFound error, fsync .ecx after the
   whole replay succeeds, and only then drop and recreate .ecj.
   NotFound is still ignored (expected race between delete and encode).

4. Missing-.ecx hardening (Rust). mark_needle_deleted_in_ecx used to
   return Ok(NotFound) when self.ecx_file was None, hiding a closed or
   corrupt volume behind what looks like an idempotent no-op. It now
   returns an io::Error carrying the volume id so callers (e.g.
   journal_delete) fail loudly instead.

Existing Go and Rust EC test suites stay green.

* ec: make .ecx immutable at runtime; track deletes in memory + .ecj

Refactors both volume servers so the sealed sorted .ecx index is never
mutated during normal operation. Runtime deletes are committed to the
.ecj deletion journal and tracked in an in-memory deleted-needle set;
read-path lookups consult that set to mask out deleted ids on top of
the immutable .ecx record. Mirrors the intended design on both Go and
Rust sides.

EcVolume gains a `deletedNeedles` / `deleted_needles` set seeded from
.ecj in NewEcVolume / EcVolume::new. DeleteNeedleFromEcx /
journal_delete:

  1. Looks the needle up read-only in .ecx.
  2. Missing needle -> no-op.
  3. Pre-existing .ecx tombstone (from a prior decode/rebuild) ->
     mirror into the in-memory set, no .ecj append.
  4. Otherwise append the id to .ecj, fsync, and only then publish
     the id into the set. A partial write is truncated back to the
     pre-append length so the on-disk journal and the in-memory set
     cannot drift.

FindNeedleFromEcx / find_needle_from_ecx now return
TombstoneFileSize when the id is in the in-memory set, even though
the bytes on disk still show the original size.

FileAndDeleteCount:
  fileCount   = .ecx size / NeedleMapEntrySize (unchanged)
  deleteCount = len(deletedNeedles) (was: .ecj size / NeedleIdSize)

The RebuildEcxFile / rebuild_ecx_from_journal decode-time helpers
still fold .ecj into .ecx — that is the one place tombstones land in
the physical index, and it runs offline on closed files. Rust's
rebuild helper now also clears the in-memory set when it succeeds.

Dead code removed on the Rust side: `DeleteOutcome`,
`mark_needle_deleted_in_ecx`, `restore_ecx_size`. Go drops the
runtime `rollbackEcxTombstone` path. Neither helper was needed once
.ecx stopped being a runtime mutation target.

TestEcVolumeSyncEnsuresDeletionsVisible (issue #7751) is rewritten
as TestEcVolumeDeleteDurableToJournal, which exercises the full
durability chain: delete -> .ecj fsync -> FindNeedleFromEcx masks
via the in-memory set -> raw .ecx bytes are *unchanged* -> Close +
RebuildEcxFile folds the journal into .ecx -> raw bytes now show
the tombstone, as CopyFile in the decode path expects.
2026-04-13 21:10:36 -07:00
Chris LuandCopilot af68449a26 Process .ecj deletions during EC decode and vacuum decoded volume (#8863)
* Process .ecj deletions during EC decode and vacuum decoded volume (#8798)

When decoding EC volumes back to normal volumes, deletions recorded in
the .ecj journal were not being applied before computing the dat file
size or checking for live needles. This caused the decoded volume to
include data for deleted files and could produce false positives in the
all-deleted check.

- Call RebuildEcxFile before HasLiveNeedles/FindDatFileSize in
  VolumeEcShardsToVolume so .ecj deletions are merged into .ecx first
- Vacuum the decoded volume after mounting in ec.decode to compact out
  deleted needle data from the .dat file
- Add integration tests for decoding with non-empty .ecj files

* storage: add offline volume compaction helper

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* ec: compact decoded volumes before deleting shards

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* ec: address PR review comments

- Fall back to data directory for .ecx when idx directory lacks it
- Make compaction failure non-fatal during EC decode
- Remove misleading "buffer: 10%" from space check error message

* ec: collect .ecj from all shard locations during decode

Each server's .ecj only contains deletions for needles whose data
resides in shards held by that server. Previously, sources with no
new data shards to contribute were skipped entirely, losing their
.ecj deletion entries. Now .ecj is always appended from every shard
location so RebuildEcxFile sees the full set of deletions.

* ec: add integration tests for .ecj collection during decode

TestEcDecodePreservesDeletedNeedles: verifies that needles deleted
via VolumeEcBlobDelete are excluded from the decoded volume.

TestEcDecodeCollectsEcjFromPeer: regression test for the fix in
collectEcShards. Deletes a needle only on a peer server that holds
no new data shards, then verifies the deletion survives decode via
.ecj collection.

* ec: address review nits in decode and tests

- Remove double error wrapping in mountDecodedVolume
- Check VolumeUnmount error in peer ecj test
- Assert 404 specifically for deleted needles, fail on 5xx

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-04-01 01:15:26 -07:00
Chris Lu 32a9a1f46f fix: sync EC volume files before copying to fix deleted needles not being marked when decoding (#7755)
* fix: sync EC volume files before copying to fix deleted needles not being marked when decoding (#7751)

When a file is deleted from an EC volume, the deletion is written to both
the .ecx and .ecj files. However, these writes were not synced to disk
before the files were copied during ec.decode. This caused the copied
files to miss the deletion markers, resulting in 'leaked' space where
deleted files were not properly tracked after decoding.

This fix:
1. Adds a Sync() method to EcVolume that flushes .ecx and .ecj files
   to disk without closing them
2. Calls Sync() in CopyFile before copying EC volume files to ensure
   all deletions are visible to the copy operation

Fixes #7751

* test: add integration tests for EC volume deletion sync (issue #7751)

Add comprehensive tests to verify that deleted needles are properly
visible after EcVolume.Sync() is called. These tests cover:

1. TestWriteIdxFileFromEcIndex_PreservesDeletedNeedles
   - Verifies that WriteIdxFileFromEcIndex preserves deletion markers
     from .ecx files when generating .idx files

2. TestWriteIdxFileFromEcIndex_ProcessesEcjJournal
   - Verifies that deletions from .ecj journal file are correctly
     appended to the generated .idx file

3. TestEcxFileDeletionVisibleAfterSync
   - Verifies that MarkNeedleDeleted changes are visible after Sync()

4. TestEcxFileDeletionWithSeparateHandles
   - Tests that synced changes are visible across separate file handles

5. TestEcVolumeSyncEnsuresDeletionsVisible
   - Integration test for the full EcVolume.DeleteNeedleFromEcx +
     Sync() workflow that validates the fix for issue #7751

* refactor: log sync errors in EcVolume.Sync() instead of ignoring them

Per code review feedback: sync errors could reintroduce the bug this PR
fixes, so logging warnings helps with debugging.
2025-12-14 21:26:05 -08:00
Chris Lu 7ed7578424 fix(ec.decode): purge EC shards when volume is empty (#7749)
* fix(ec.decode): purge EC shards when volume is empty

When an EC volume has no live entries (all deleted), ec.decode should not generate an empty normal volume. Instead, treat decode as a no-op and allow shard purge to proceed cleanly.\n\nFixes: #7748

* chore: address PR review comments

* test: cover live EC index + avoid magic string

* chore: harden empty-EC handling

- Make shard cleanup best-effort (collect errors)\n- Remove unreachable EOF handling in HasLiveNeedles\n- Add empty ecx test case\n- Share no-live-entries substring between server/client\n

* perf: parallelize EC shard unmount/delete across locations

* refactor: combine unmount+delete into single goroutine per location

* refactor: use errors.Join for multi-error aggregation

* refactor: use existing ErrorWaitGroup for parallel execution

* fix: capture loop variables + clarify SuperBlockSize safety
2025-12-14 17:06:13 -08:00