Files
seaweedfs/seaweed-volume/src/server
8c1ebbee32 volume server: split get_or_head_handler_inner into phases (#11489)
* volume server: read GET/HEAD needles off the store lock, and only once

The GET/HEAD handler read the needle synchronously on the tokio worker
while holding store.read(): first a stream-info read that loaded the
whole record just to parse its meta, then, for every needle that was not
streamed (small, compressed, chunk manifest, image ops), a second full
read. For a tiered volume each read is an S3 GET under the store lock,
and a writer queued behind it parks every other store reader.

The regular-volume read now runs in spawn_blocking. Under the store guard
it only resolves a NeedleReadPlan (index lookup, a freshly opened .dat
handle or the remote backend, offset, size); the guard is dropped before
any needle data I/O. No data-file lease is held across the read either,
since a writer waits for one while holding the store write lock. The
index size decides the read, as in Go's readNeedle: a HEAD, a ranged read
or a needle above the stream threshold reads only its header and meta
tail (ReadNeedleMeta) and hands off to StreamingBody or the range path;
everything else is read in full once, with its checksum verified. A
compressed or manifest needle found by the meta read is then read in
full once. The range-from-source read also moves to spawn_blocking.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

* volume server: stream needle chunks without the store lock

StreamingBody::poll_frame took store.read() and find_volume for every
chunk to compare the volume's compaction revision, dup'd the source
handle, and allocated a fresh chunk buffer. With -hasSlowRead=false the
stream also holds a data-file read lease for its whole life, while a
writer waits for that lease under store.write(): the next chunk's
store.read() then waits for the writer and the writer for the stream.

The per-chunk re-lookup was also wrong. The stream reads a handle opened
at plan time, which pins the .dat inode the offset was resolved against;
a vacuum commit renames a new file over .dat and leaves that inode
untouched. The re-looked-up offset belongs to the new file but was read
from the old inode, so a stream whose needle a vacuum moved ended in a
checksum error. The pinned offset stays valid, so the check, and with
it every store access, is dropped, along with the now unused
re_lookup_needle_data_offset and the revision fields of the read plan.

The source is shared as an Arc instead of dup'd per chunk, and the chunk
buffer is a BytesMut that the blocking read hands back with its result,
so its allocation is reclaimed once the previous frame has been written.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

* volume server: split get_or_head_handler_inner into phases

get_or_head_handler_inner was a ~650-line function. Its middle resolved
the needle and set five mutable flags (stream_info, can_stream,
can_handle_head_from_meta, can_handle_range_from_source, bypass_cm) that
three if-let reply paths then re-tested, each re-checking stream_info.

It is now a 126-line orchestrator over named phases: reject_read_jwt,
proxy_missing_volume, wait_for_download_slot, parse_read_request,
read_ec_needle / read_volume_needle, etag_and_last_modified,
not_modified_response, read_response_headers, and the reply phases
stream_response, head_from_meta_response, range_from_source_response,
buffered_payload and buffered_response. The read phases return a
ReadPlan whose ReadStrategy enum (Stream, HeadFromMeta, RangeFromSource,
Buffered) carries the NeedleStreamInfo only on the variants that use it,
so the reply is one match instead of three flag checks.

Pure refactor: every status code, header and header order, error text,
metric increment, lock and data-file lease scope, spawn_blocking
boundary and side-effect order is unchanged. Phases that can end the
request return ControlFlow<Response, T>. A Range header that is not
visible ASCII still falls through to the buffered path, as before.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

* volume server: stop a needle stream once its volume becomes unavailable

Taking the store lock out of StreamingBody also dropped its per-chunk
unavailable_error() check. With -hasSlowRead a writer can take the
data-file lease between chunks, fail its fsync and its truncate, and mark
the volume unavailable; the stream then kept serving the rest of the
needle from its pinned handle.

The volume's io_unavailable reason is now an Arc-shared leaf mutex that
the read plan hands to the stream. Each chunk checks it under its
data-file lease, where the writer marks it, and fails with the same
"volume is unavailable: <reason>" error the old check returned.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

* volume server: mirror Go order in the buffered read path

- check HEAD before Range in buffered_response (writeResponseContent
  order); an EC-volume HEAD with a Range header answered 206, Go
  answers 200
- treat the proxied flag as an exact query pair like Go's parsed
  lookup, not a substring
- name the phases after their Go counterparts: check_download_limit
  and read_ec_shard_needle; reuse has_replication()
- drop comments that restate the code or cite Go line numbers

---------

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Co-authored-by: Chris Lu <chrislusf@users.noreply.github.com>
Co-authored-by: Chris Lu <chris.lu@gmail.com>
2026-10-03 17:54:46 +08:00
..
2026-04-23 10:05:51 -07:00