* mount: improve read throughput with parallel chunk fetching
This addresses issue #7504 where a single weed mount FUSE instance
does not fully utilize node network bandwidth when reading large files.
Changes:
- Add -concurrentReaders mount option (default: 16) to control the
maximum number of parallel chunk fetches during read operations
- Implement parallel section reading in ChunkGroup.ReadDataAt() using
errgroup for better throughput when reading across multiple sections
- Enhance ReaderCache with MaybeCacheMany() to prefetch multiple chunks
ahead in parallel during sequential reads (now prefetches 4 chunks)
- Increase ReaderCache limit dynamically based on concurrentReaders
to support higher read parallelism
The bottleneck was that chunks were being read sequentially even when
they reside on different volume servers. By introducing parallel chunk
fetching, a single mount instance can now better saturate available
network bandwidth.
Fixes: #7504
* fmt
* Address review comments: make prefetch configurable, improve error handling
Changes:
1. Add DefaultPrefetchCount constant (4) to reader_at.go
2. Add GetPrefetchCount() method to ChunkGroup that derives prefetch count
from concurrentReaders (1/4 ratio, min 1, max 8)
3. Pass prefetch count through NewChunkReaderAtFromClient
4. Fix error handling in readDataAtParallel to prioritize errgroup error
5. Update all callers to use DefaultPrefetchCount constant
For mount operations, prefetch scales with -concurrentReaders:
- concurrentReaders=16 (default) -> prefetch=4
- concurrentReaders=32 -> prefetch=8 (capped)
- concurrentReaders=4 -> prefetch=1
For non-mount paths (WebDAV, query engine, MQ), uses DefaultPrefetchCount.
* fmt
* Refactor: use variadic parameter instead of new function name
Use NewChunkGroup with optional concurrentReaders parameter instead of
creating a separate NewChunkGroupWithConcurrency function.
This maintains backward compatibility - existing callers without the
parameter get the default of 16 concurrent readers.
* Use explicit concurrentReaders parameter instead of variadic
* Refactor: use MaybeCache with count parameter instead of new MaybeCacheMany function
* Address nitpick review comments
- Add upper bound (128) on concurrentReaders to prevent excessive goroutine fan-out
- Cap readerCacheLimit at 256 accordingly
- Fix SetChunks: use Lock() instead of RLock() since we are writing to group.sections
* feature: we can check if a fileId is already in the cache
We using this to protect cache from adding the same needle to
the cache over and over.
* fuse mount: Do not start dowloader if needle is already in the cache
* added maxFilePartSizeInCache property to ChunkCache
If file very large only first maxFilePartSizeInCache bytes
are going to be put to the cache (subject to the needle size
constrains).
* feature: for large files put in cache no more than prescribed number of bytes
Before this patch only the first needle of a large file was intended for
caching. This patch uses maximum prescribed amount of bytes to be put in
cache. This allows to bypass default 2MB maximum for a file part stored
in the cache.
* added dummy mock methods to satisfy interfaces of ChunkCache
* Added global http client
* Added Do func for global http client
* Changed the code to use the global http client
* Fix http client in volume uploader
* Fixed pkg name
* Fixed http util funcs
* Fixed http client for bench_filer_upload
* Fixed http client for stress_filer_upload
* Fixed http client for filer_server_handlers_proxy
* Fixed http client for command_fs_merge_volumes
* Fixed http client for command_fs_merge_volumes and command_volume_fsck
* Fixed http client for s3api_server
* Added init global client for main funcs
* Rename global_client to client
* Changed:
- fixed NewHttpClient;
- added CheckIsHttpsClientEnabled func
- updated security.toml in scaffold
* Reduce the visibility of some functions in the util/http/client pkg
* Added the loadSecurityConfig function
* Use util.LoadSecurityConfiguration() in NewHttpClient func
* compare chunks by timestamp
* fix slab clearing error
* fix test compilation
* move oldest chunk to sealed, instead of by fullness
* lock on fh.entryViewCache
* remove verbose logs
* revert slat clearing
* less logs
* less logs
* track write and read by timestamp
* remove useless logic
* add entry lock on file handle release
* use mem chunk only, swap file chunk has problems
* comment out code that maybe used later
* add debug mode to compare data read and write
* more efficient readResolvedChunks with linked list
* small optimization
* fix test compilation
* minor fix on writer
* add SeparateGarbageChunks
* group chunks into sections
* turn off debug mode
* fix tests
* fix tests
* tmp enable swap file chunk
* Revert "tmp enable swap file chunk"
This reverts commit 985137ec472924e4815f258189f6ca9f2168a0a7.
* simple refactoring
* simple refactoring
* do not re-use swap file chunk. Sealed chunks should not be re-used.
* comment out debugging facilities
* either mem chunk or swap file chunk is fine now
* remove orderedMutex as *semaphore.Weighted
not found impactful
* optimize size calculation for changing large files
* optimize performance to avoid going through the long list of chunks
* still problems with swap file chunk
* rename
* tiny optimization
* swap file chunk save only successfully read data
* fix
* enable both mem and swap file chunk
* resolve chunks with range
* rename
* fix chunk interval list
* also change file handle chunk group when adding chunks
* pick in-active chunk with time-decayed counter
* fix compilation
* avoid nil with empty fh.entry
* refactoring
* rename
* rename
* refactor visible intervals to *list.List
* refactor chunkViews to *list.List
* add IntervalList for generic interval list
* change visible interval to use IntervalList in generics
* cahnge chunkViews to *IntervalList[*ChunkView]
* use NewFileChunkSection to create
* rename variables
* refactor
* fix renaming leftover
* renaming
* renaming
* add insert interval
* interval list adds lock
* incrementally add chunks to readers
Fixes:
1. set start and stop offset for the value object
2. clone the value object
3. use pointer instead of copy-by-value when passing to interval.Value
4. use insert interval since adding chunk could be out of order
* fix tests compilation
* fix tests compilation
Sometimes when an unexpected error occurs the cacher would set an
error and return. However, it would not broadcast the condition
signal in that case, therefore leaving the goroutine that runs
readChunkAt stuck forever.
I figured that the condition is unnecessary because readChunkAt is
acquiring a lock that is still held by the cacher goroutine anyway.
Callees of startCaching have to wait for a WaitGroup which makes sure
that readChunkAt can't acquire the lock before startCaching.
This way readChunkAt can execute normally and check for the error.
