* improve large file sync throughput for remote.cache and filer.sync
Three main throughput improvements:
1. Adaptive chunk sizing for remote.cache: targets ~32 chunks per file
instead of always starting at 5MB. A 500MB file now uses ~16MB chunks
(32 chunks) instead of 5MB chunks (100 chunks), reducing per-chunk
overhead (volume assign, gRPC call, needle write) by 3x.
2. Configurable concurrency at every layer:
- remote.cache chunk concurrency: -chunkConcurrency flag (default 8)
- remote.cache S3 download concurrency: -downloadConcurrency flag
(default raised from 1 to 5 per chunk)
- filer.sync chunk concurrency: -chunkConcurrency flag (default 32)
3. S3 multipart download concurrency raised from 1 to 5: the S3 manager
downloader was using Concurrency=1, serializing all part downloads
within each chunk. This alone can 5x per-chunk download speed.
The concurrency values flow through the gRPC request chain:
shell command → CacheRemoteObjectToLocalClusterRequest →
FetchAndWriteNeedleRequest → S3 downloader
Zero values in the request mean "use server defaults", maintaining
full backward compatibility with existing callers.
Ref #8481
* fix: use full maxMB for chunk size cap and remove loop guard
Address review feedback:
- Use full maxMB instead of maxMB/2 for maxChunkSize to avoid
unnecessarily limiting chunk size for very large files.
- Remove chunkSize < maxChunkSize guard from the safety loop so it
can always grow past maxChunkSize when needed to stay under 1000
chunks (e.g., extremely large files with small maxMB).
* address review feedback: help text, validation, naming, docs
- Fix help text for -chunkConcurrency and -downloadConcurrency flags
to say "0 = server default" instead of advertising specific numeric
defaults that could drift from the server implementation.
- Validate chunkConcurrency and downloadConcurrency are within int32
range before narrowing, returning a user-facing error if out of range.
- Rename ReadRemoteErr to readRemoteErr to follow Go naming conventions.
- Add doc comment to SetChunkConcurrency noting it must be called
during initialization before replication goroutines start.
- Replace doubling loop in chunk size safety check with direct
ceil(remoteSize/1000) computation to guarantee the 1000-chunk cap.
* address Copilot review: clamp concurrency, fix chunk count, clarify proto docs
- Use ceiling division for chunk count check to avoid overcounting
when file size is an exact multiple of chunk size.
- Clamp chunkConcurrency (max 1024) and downloadConcurrency (max 1024
at filer, max 64 at volume server) to prevent excessive goroutines.
- Always use ReadFileWithConcurrency when the client supports it,
falling back to the implementation's default when value is 0.
- Clarify proto comments that download_concurrency only applies when
the remote storage client supports it (currently S3).
- Include specific server defaults in help text (e.g., "0 = server
default 8") so users see the actual values in -h output.
* fix data race on executionErr and use %w for error wrapping
- Protect concurrent writes to executionErr in remote.cache worker
goroutines with a sync.Mutex to eliminate the data race.
- Use %w instead of %v in volume_grpc_remote.go error formatting
to preserve the error chain for errors.Is/errors.As callers.
* feat(filer): add lazy directory listing for remote mounts
Directory listings on remote mounts previously only queried the local
filer store. With lazy mounts the listing was empty; with eager mounts
it went stale over time.
Add on-demand directory listing that fetches from remote and caches
results with a 5-minute TTL:
- Add `ListDirectory` to `RemoteStorageClient` interface (delimiter-based,
single-level listing, separate from recursive `Traverse`)
- Implement in S3, GCS, and Azure backends using each platform's
hierarchical listing API
- Add `maybeLazyListFromRemote` to filer: before each directory listing,
check if the directory is under a remote mount with an expired cache,
fetch from remote, persist entries to the local store, then let existing
listing logic run on the populated store
- Use singleflight to deduplicate concurrent requests for the same directory
- Skip local-only entries (no RemoteEntry) to avoid overwriting unsynced uploads
- Errors are logged and swallowed (availability over consistency)
* refactor: extract xattr key to constant xattrRemoteListingSyncedAt
* feat: make listing cache TTL configurable per mount via listing_cache_ttl_seconds
Add listing_cache_ttl_seconds field to RemoteStorageLocation protobuf.
When 0 (default), lazy directory listing is disabled for that mount.
When >0, enables on-demand directory listing with the specified TTL.
Expose as -listingCacheTTL flag on remote.mount command.
* refactor: address review feedback for lazy directory listing
- Add context.Context to ListDirectory interface and all implementations
- Capture startTime before remote call for accurate TTL tracking
- Simplify S3 ListDirectory using ListObjectsV2PagesWithContext
- Make maybeLazyListFromRemote return void (errors always swallowed)
- Remove redundant trailing-slash path manipulation in caller
- Update tests to match new signatures
* When an existing entry has Remote != nil, we should merge remote metadata into it rather than replacing it.
* fix(gcs): wrap ListDirectory iterator error with context
The raw iterator error was returned without bucket/path context,
making it harder to debug. Wrap it consistently with the S3 pattern.
* fix(s3): guard against nil pointer dereference in Traverse and ListDirectory
Some S3-compatible backends may return nil for LastModified, Size, or
ETag fields. Check for nil before dereferencing to prevent panics.
* fix(filer): remove blanket 2-minute timeout from lazy listing context
Individual SDK operations (S3, GCS, Azure) already have per-request
timeouts and retry policies. The blanket timeout could cut off large
directory listings mid-operation even though individual pages were
succeeding.
* fix(filer): preserve trace context in lazy listing with WithoutCancel
Use context.WithoutCancel(ctx) instead of context.Background() so
trace/span values from the incoming request are retained for
distributed tracing, while still decoupling cancellation.
* fix(filer): use Store.FindEntry for internal lookups, add Uid/Gid to files, fix updateDirectoryListingSyncedAt
- Use f.Store.FindEntry instead of f.FindEntry for staleness check and
child lookups to avoid unnecessary lazy-fetch overhead
- Set OS_UID/OS_GID on new file entries for consistency with directories
- In updateDirectoryListingSyncedAt, use Store.UpdateEntry for existing
directories instead of CreateEntry to avoid deleteChunksIfNotNew and
NotifyUpdateEvent side effects
* fix(filer): distinguish not-found from store errors in lazy listing
Previously, any error from Store.FindEntry was treated as "not found,"
which could cause entry recreation/overwrite on transient DB failures.
Now check for filer_pb.ErrNotFound explicitly and skip entries or
bail out on real store errors.
* refactor(filer): use errors.Is for ErrNotFound comparisons
* feat: add statfile; add error for remote storage misses
* feat: statfile implementations for storage providers
* test: add unit tests for StatFile method across providers
Add comprehensive unit tests for the StatFile implementation covering:
- S3: interface compliance and error constant accessibility
- Azure: interface compliance, error constants, and field population
- GCS: interface compliance, error constants, error detection, and field population
Also fix variable shadowing issue in S3 and Azure StatFile implementations where
named return parameters were being shadowed by local variable declarations.
Co-authored-by: Cursor <cursoragent@cursor.com>
* fix: address StatFile review feedback
- Use errors.New for ErrRemoteObjectNotFound sentinel
- Fix S3 HeadObject 404 detection to use awserr.Error code check
- Remove hollow field-population tests that tested nothing
- Remove redundant stdlib error detection tests
- Trim verbose doc comment on ErrRemoteObjectNotFound
Co-authored-by: Cursor <cursoragent@cursor.com>
* fix: address second round of StatFile review feedback
- Rename interface assertion tests to TestXxxRemoteStorageClientImplementsInterface
- Delegate readFileRemoteEntry to StatFile in all three providers
- Revert S3 404 detection to RequestFailure.StatusCode() check
- Fix double-slash in GCS error message format string
- Add storage type prefix to S3 error message for consistency
Co-authored-by: Cursor <cursoragent@cursor.com>
* fix: comments
---------
Co-authored-by: Cursor <cursoragent@cursor.com>
* chore: execute goimports to format the code
Signed-off-by: promalert <promalert@outlook.com>
* goimports -w .
---------
Signed-off-by: promalert <promalert@outlook.com>
Co-authored-by: Chris Lu <chris.lu@gmail.com>
Chris Lu
Peter Dodd
promalert
chrislu
justin