* Fix ec.rebuild failing on unrepairable volumes instead of skipping them
When an EC volume has fewer shards than DataShardsCount, ec.rebuild would
return an error and abort the entire operation. Now it logs a warning and
continues rebuilding the remaining volumes.
Fixes#8630
* Remove duplicate volume ID in unrepairable log message
---------
Co-authored-by: Copilot <copilot@github.com>
* opt: reduce ShardsInfo memory usage with bitmap and sorted slice
- Replace map[ShardId]*ShardInfo with sorted []ShardInfo slice
- Add ShardBits (uint32) bitmap for O(1) existence checks
- Use binary search for O(log n) lookups by shard ID
- Maintain sorted order for efficient iteration
- Add comprehensive unit tests and benchmarks
Memory savings:
- Map overhead: ~48 bytes per entry eliminated
- Pointers: 8 bytes per entry eliminated
- Total: ~56 bytes per shard saved
Performance improvements:
- Has(): O(1) using bitmap
- Size(): O(log n) using binary search (was O(1), acceptable tradeoff)
- Count(): O(1) using popcount on bitmap
- Iteration: Faster due to cache locality
* refactor: add methods to ShardBits type
- Add Has(), Set(), Clear(), and Count() methods to ShardBits
- Simplify ShardsInfo methods by using ShardBits methods
- Improves code readability and encapsulation
* opt: use ShardBits directly in ShardsCountFromVolumeEcShardInformationMessage
Avoid creating a full ShardsInfo object just to count shards.
Directly cast vi.EcIndexBits to ShardBits and use Count() method.
* opt: use strings.Builder in ShardsInfo.String() for efficiency
* refactor: change AsSlice to return []ShardInfo (values instead of pointers)
This completes the memory optimization by avoiding unnecessary pointer slices and potential allocations.
* refactor: rename ShardsCountFromVolumeEcShardInformationMessage to GetShardCount
* fix: prevent deadlock in Add and Subtract methods
Copy shards data from 'other' before releasing its lock to avoid
potential deadlock when a.Add(b) and b.Add(a) are called concurrently.
The previous implementation held other's lock while calling si.Set/Delete,
which acquires si's lock. This could deadlock if two goroutines tried to
add/subtract each other concurrently.
* opt: avoid unnecessary locking in constructor functions
ShardsInfoFromVolume and ShardsInfoFromVolumeEcShardInformationMessage
now build shards slice and bitmap directly without calling Set(), which
acquires a lock on every call. Since the object is local and not yet
shared, locking is unnecessary and adds overhead.
This improves performance during object construction.
* fix: rename 'copy' variable to avoid shadowing built-in function
The variable name 'copy' in TestShardsInfo_Copy shadowed the built-in
copy() function, which is confusing and bad practice. Renamed to 'siCopy'.
* opt: use math/bits.OnesCount32 and reorganize types
1. Replace manual popcount loop with math/bits.OnesCount32 for better
performance and idiomatic Go code
2. Move ShardSize type definition to ec_shards_info.go for better code
organization since it's primarily used there
* refactor: Set() now accepts ShardInfo for future extensibility
Changed Set(id ShardId, size ShardSize) to Set(shard ShardInfo) to
support future additions to ShardInfo without changing the API.
This makes the code more extensible as new fields can be added to
ShardInfo (e.g., checksum, location, etc.) without breaking the Set API.
* refactor: move ShardInfo and ShardSize to separate file
Created ec_shard_info.go to hold the basic shard types (ShardInfo and
ShardSize) for better code organization and separation of concerns.
* refactor: add ShardInfo constructor and helper functions
Added NewShardInfo() constructor and IsValid() method to better
encapsulate ShardInfo creation and validation. Updated code to use
the constructor for cleaner, more maintainable code.
* fix: update remaining Set() calls to use NewShardInfo constructor
Fixed compilation errors in storage and shell packages where Set() calls
were not updated to use the new NewShardInfo() constructor.
* fix: remove unreachable code in filer backup commands
Removed unreachable return statements after infinite loops in
filer_backup.go and filer_meta_backup.go to fix compilation errors.
* fix: rename 'new' variable to avoid shadowing built-in
Renamed 'new' to 'result' in MinusParityShards, Plus, and Minus methods
to avoid shadowing Go's built-in new() function.
* fix: update remaining test files to use NewShardInfo constructor
Fixed Set() calls in command_volume_list_test.go and
ec_rebalance_slots_test.go to use NewShardInfo() constructor.
* ec: add diskType parameter to core EC functions
Add diskType parameter to:
- ecBalancer struct
- collectEcVolumeServersByDc()
- collectEcNodesForDC()
- collectEcNodes()
- EcBalance()
This allows EC operations to target specific disk types (hdd, ssd, etc.)
instead of being hardcoded to HardDriveType only.
For backward compatibility, all callers currently pass types.HardDriveType
as the default value. Subsequent commits will add -diskType flags to
the individual EC commands.
* ec: update helper functions to use configurable diskType
Update the following functions to accept/use diskType parameter:
- findEcVolumeShards()
- addEcVolumeShards()
- deleteEcVolumeShards()
- moveMountedShardToEcNode()
- countShardsByRack()
- pickNEcShardsToMoveFrom()
All ecBalancer methods now use ecb.diskType instead of hardcoded
types.HardDriveType. Non-ecBalancer callers (like volumeServer.evacuate
and ec.rebuild) use types.HardDriveType as the default.
Update all test files to pass diskType where needed.
* ec: add -diskType flag to ec.balance and ec.encode commands
Add -diskType flag to specify the target disk type for EC operations:
- ec.balance -diskType=ssd
- ec.encode -diskType=ssd
The disk type can be 'hdd', 'ssd', or empty for default (hdd).
This allows placing EC shards on SSD or other disk types instead of
only HDD.
Example usage:
ec.balance -collection=mybucket -diskType=ssd -apply
ec.encode -collection=mybucket -diskType=ssd -force
* test: add integration tests for EC disk type support
Add integration tests to verify the -diskType flag works correctly:
- TestECDiskTypeSupport: Tests EC encode and balance with SSD disk type
- TestECDiskTypeMixedCluster: Tests EC operations on a mixed HDD/SSD cluster
The tests verify:
- Volume servers can be configured with specific disk types
- ec.encode accepts -diskType flag and encodes to the correct disk type
- ec.balance accepts -diskType flag and balances on the correct disk type
- Mixed disk type clusters work correctly with separate collections
* ec: add -sourceDiskType to ec.encode and -diskType to ec.decode
ec.encode:
- Add -sourceDiskType flag to filter source volumes by disk type
- This enables tier migration scenarios (e.g., SSD volumes → HDD EC shards)
- -diskType specifies target disk type for EC shards
ec.decode:
- Add -diskType flag to specify source disk type where EC shards are stored
- Update collectEcShardIds() and collectEcNodeShardBits() to accept diskType
Examples:
# Encode SSD volumes to HDD EC shards (tier migration)
ec.encode -collection=mybucket -sourceDiskType=ssd -diskType=hdd
# Decode EC shards from SSD
ec.decode -collection=mybucket -diskType=ssd
Integration tests updated to cover new flags.
* ec: fix variable shadowing and add -diskType to ec.rebuild and volumeServer.evacuate
Address code review comments:
1. Fix variable shadowing in collectEcVolumeServersByDc():
- Rename loop variable 'diskType' to 'diskTypeKey' and 'diskTypeStr'
to avoid shadowing the function parameter
2. Fix hardcoded HardDriveType in ecBalancer methods:
- balanceEcRack(): use ecb.diskType instead of types.HardDriveType
- collectVolumeIdToEcNodes(): use ecb.diskType
3. Add -diskType flag to ec.rebuild command:
- Add diskType field to ecRebuilder struct
- Pass diskType to collectEcNodes() and addEcVolumeShards()
4. Add -diskType flag to volumeServer.evacuate command:
- Add diskType field to commandVolumeServerEvacuate struct
- Pass diskType to collectEcVolumeServersByDc() and moveMountedShardToEcNode()
* test: add diskType field to ecBalancer in TestPickEcNodeToBalanceShardsInto
Address nitpick comment: ensure test ecBalancer struct has diskType
field set for consistency with other tests.
* ec: filter disk selection by disk type in pickBestDiskOnNode
When evacuating or rebalancing EC shards, pickBestDiskOnNode now
filters disks by the target disk type. This ensures:
1. EC shards from SSD disks are moved to SSD disks on destination nodes
2. EC shards from HDD disks are moved to HDD disks on destination nodes
3. No cross-disk-type shard movement occurs
This maintains the storage tier isolation when moving EC shards
between nodes during evacuation or rebalancing operations.
* ec: allow disk type fallback during evacuation
Update pickBestDiskOnNode to accept a strictDiskType parameter:
- strictDiskType=true (balancing): Only use disks of matching type.
This maintains storage tier isolation during normal rebalancing.
- strictDiskType=false (evacuation): Prefer same disk type, but
fall back to other disk types if no matching disk is available.
This ensures evacuation can complete even when same-type capacity
is insufficient.
Priority order for evacuation:
1. Same disk type with lowest shard count (preferred)
2. Different disk type with lowest shard count (fallback)
* test: use defer for lock/unlock to prevent lock leaks
Use defer to ensure locks are always released, even on early returns
or test failures. This prevents lock leaks that could cause subsequent
tests to hang or fail.
Changes:
- Return early if lock acquisition fails
- Immediately defer unlock after successful lock
- Remove redundant explicit unlock calls at end of tests
- Fix unused variable warning (err -> encodeErr/locErr)
* ec: dynamically discover disk types from topology for evacuation
Disk types are free-form tags (e.g., 'ssd', 'nvme', 'archive') that come
from the topology, not a hardcoded set. Only 'hdd' (or empty) is the
default disk type.
Use collectVolumeDiskTypes() to discover all disk types present in the
cluster topology instead of hardcoding [HardDriveType, SsdType].
* test: add evacuation fallback and cross-rack EC placement tests
Add two new integration tests:
1. TestEvacuationFallbackBehavior:
- Tests that when same disk type has no capacity, shards fall back
to other disk types during evacuation
- Creates cluster with 1 SSD + 2 HDD servers (limited SSD capacity)
- Verifies pickBestDiskOnNode behavior with strictDiskType=false
2. TestCrossRackECPlacement:
- Tests EC shard distribution across different racks
- Creates cluster with 4 servers in 4 different racks
- Verifies shards are spread across multiple racks
- Tests that ec.balance respects rack placement
Helper functions added:
- startLimitedSsdCluster: 1 SSD + 2 HDD servers
- startMultiRackCluster: 4 servers in 4 racks
- countShardsPerRack: counts EC shards per rack from disk
* test: fix collection mismatch in TestCrossRackECPlacement
The EC commands were using collection 'rack_test' but uploaded test data
uses collection 'test' (default). This caused ec.encode/ec.balance to not
find the uploaded volume.
Fix: Change EC commands to use '-collection test' to match the uploaded data.
Addresses review comment from PR #7607.
* test: close log files in MultiDiskCluster.Stop() to prevent FD leaks
Track log files in MultiDiskCluster.logFiles and close them in Stop()
to prevent file descriptor accumulation in long-running or many-test
scenarios.
Addresses review comment about logging resources cleanup.
* test: improve EC integration tests with proper assertions
- Add assertNoFlagError helper to detect flag parsing regressions
- Update diskType subtests to fail on flag errors (ec.encode, ec.balance, ec.decode)
- Update verify_disktype_flag_parsing to check help output contains diskType
- Remove verify_fallback_disk_selection (was documentation-only, not executable)
- Add assertion to verify_cross_rack_distribution for minimum 2 racks
- Consolidate uploadTestDataWithDiskType to accept collection parameter
- Remove duplicate uploadTestDataWithDiskTypeMixed function
* test: extract captureCommandOutput helper and fix error handling
- Add captureCommandOutput helper to reduce code duplication in diskType tests
- Create commandRunner interface to match shell command Do method
- Update ec_encode_with_ssd_disktype, ec_balance_with_ssd_disktype,
ec_encode_with_source_disktype, ec_decode_with_disktype to use helper
- Fix filepath.Glob error handling in countShardsPerRack instead of ignoring it
* test: add flag validation to ec_balance_targets_correct_disk_type
Add assertNoFlagError calls after ec.balance commands to ensure
-diskType flag is properly recognized for both SSD and HDD disk types.
* test: add proper assertions for EC command results
- ec_encode_with_ssd_disktype: check for expected volume-related errors
- ec_balance_with_ssd_disktype: require success with require.NoError
- ec_encode_with_source_disktype: check for expected no-volume errors
- ec_decode_with_disktype: check for expected no-ec-volume errors
- upload_to_ssd_and_hdd: use require.NoError for setup validation
Tests now properly fail on unexpected errors rather than just logging.
* test: fix missing unlock in ec_encode_with_disk_awareness
Add defer unlock pattern to ensure lock is always released, matching
the pattern used in other subtests.
* test: improve helper robustness
- Make assertNoFlagError case-insensitive for pattern matching
- Use defer in captureCommandOutput to restore stdout/stderr and close
pipe ends to avoid FD leaks even if cmd.Do panics
* Parallelize `ec.rebuild` operations per affected volume.
* node.freeEcSlot >= slotsNeeded
* variable names, help messages,
* Protected the read operation with the same mutex
* accurate error message
* fix broken test
---------
Co-authored-by: chrislu <chris.lu@gmail.com>
Co-authored-by: Chris Lu <chrislusf@users.noreply.github.com>
* Rework parameters passing for functions within `ec.rebuild`
This simplifies the overall codebase and allows to cleanly handle parallelization via waitgroups.
* fix copy source
* add tests
* remove tests not useful
* fmt
* nil check
---------
Co-authored-by: Chris Lu <chrislusf@users.noreply.github.com>
Co-authored-by: chrislu <chris.lu@gmail.com>
* Unify the parameter to disable dry-run on weed shell commands to --apply (instead of --force).
* lint
* refactor
* Execution Order Corrected
* handle deprecated force flag
* fix help messages
* Refactoring]: Using flag.FlagSet.Visit()
* consistent with other commands
* Checks for both flags
* fix toml files
---------
Co-authored-by: chrislu <chris.lu@gmail.com>
* refactor: add ECContext structure to encapsulate EC parameters
- Create ec_context.go with ECContext struct
- NewDefaultECContext() creates context with default 10+4 configuration
- Helper methods: CreateEncoder(), ToExt(), String()
- Foundation for cleaner function signatures
- No behavior change, still uses hardcoded 10+4
* refactor: update ec_encoder.go to use ECContext
- Add WriteEcFilesWithContext() and RebuildEcFilesWithContext() functions
- Keep old functions for backward compatibility (call new versions)
- Update all internal functions to accept ECContext parameter
- Use ctx.DataShards, ctx.ParityShards, ctx.TotalShards consistently
- Use ctx.CreateEncoder() instead of hardcoded reedsolomon.New()
- Use ctx.ToExt() for shard file extensions
- No behavior change, still uses default 10+4 configuration
* refactor: update ec_volume.go to use ECContext
- Add ECContext field to EcVolume struct
- Initialize ECContext with default configuration in NewEcVolume()
- Update LocateEcShardNeedleInterval() to use ECContext.DataShards
- Phase 1: Always uses default 10+4 configuration
- No behavior change
* refactor: add EC shard count fields to VolumeInfo protobuf
- Add data_shards_count field (field 8) to VolumeInfo message
- Add parity_shards_count field (field 9) to VolumeInfo message
- Fields are optional, 0 means use default (10+4)
- Backward compatible: fields added at end
- Phase 1: Foundation for future customization
* refactor: regenerate protobuf Go files with EC shard count fields
- Regenerated volume_server_pb/*.go with new EC fields
- DataShardsCount and ParityShardsCount accessors added to VolumeInfo
- No behavior change, fields not yet used
* refactor: update VolumeEcShardsGenerate to use ECContext
- Create ECContext with default configuration in VolumeEcShardsGenerate
- Use ecCtx.TotalShards and ecCtx.ToExt() in cleanup
- Call WriteEcFilesWithContext() instead of WriteEcFiles()
- Save EC configuration (DataShardsCount, ParityShardsCount) to VolumeInfo
- Log EC context being used
- Phase 1: Always uses default 10+4 configuration
- No behavior change
* fmt
* refactor: update ec_test.go to use ECContext
- Update TestEncodingDecoding to create and use ECContext
- Update validateFiles() to accept ECContext parameter
- Update removeGeneratedFiles() to use ctx.TotalShards and ctx.ToExt()
- Test passes with default 10+4 configuration
* refactor: use EcShardConfig message instead of separate fields
* optimize: pre-calculate row sizes in EC encoding loop
* refactor: replace TotalShards field with Total() method
- Remove TotalShards field from ECContext to avoid field drift
- Add Total() method that computes DataShards + ParityShards
- Update all references to use ctx.Total() instead of ctx.TotalShards
- Read EC config from VolumeInfo when loading EC volumes
- Read data shard count from .vif in VolumeEcShardsToVolume
- Use >= instead of > for exact boundary handling in encoding loops
* optimize: simplify VolumeEcShardsToVolume to use existing EC context
- Remove redundant CollectEcShards call
- Remove redundant .vif file loading
- Use v.ECContext.DataShards directly (already loaded by NewEcVolume)
- Slice tempShards instead of collecting again
* refactor: rename MaxShardId to MaxShardCount for clarity
- Change from MaxShardId=31 to MaxShardCount=32
- Eliminates confusing +1 arithmetic (MaxShardId+1)
- More intuitive: MaxShardCount directly represents the limit
fix: support custom EC ratios beyond 14 shards in VolumeEcShardsToVolume
- Add MaxShardId constant (31, since ShardBits is uint32)
- Use MaxShardId+1 (32) instead of TotalShardsCount (14) for tempShards buffer
- Prevents panic when slicing for volumes with >14 total shards
- Critical fix for custom EC configurations like 20+10
* fix: add validation for EC shard counts from VolumeInfo
- Validate DataShards/ParityShards are positive and within MaxShardCount
- Prevent zero or invalid values that could cause divide-by-zero
- Fallback to defaults if validation fails, with warning log
- VolumeEcShardsGenerate now preserves existing EC config when regenerating
- Critical safety fix for corrupted or legacy .vif files
* fix: RebuildEcFiles now loads EC config from .vif file
- Critical: RebuildEcFiles was always using default 10+4 config
- Now loads actual EC config from .vif file when rebuilding shards
- Validates config before use (positive shards, within MaxShardCount)
- Falls back to default if .vif missing or invalid
- Prevents data corruption when rebuilding custom EC volumes
* add: defensive validation for dataShards in VolumeEcShardsToVolume
- Validate dataShards > 0 and <= MaxShardCount before use
- Prevents panic from corrupted or uninitialized ECContext
- Returns clear error message instead of panic
- Defense-in-depth: validates even though upstream should catch issues
* fix: replace TotalShardsCount with MaxShardCount for custom EC ratio support
Critical fixes to support custom EC ratios > 14 shards:
disk_location_ec.go:
- validateEcVolume: Check shards 0-31 instead of 0-13 during validation
- removeEcVolumeFiles: Remove shards 0-31 instead of 0-13 during cleanup
ec_volume_info.go ShardBits methods:
- ShardIds(): Iterate up to MaxShardCount (32) instead of TotalShardsCount (14)
- ToUint32Slice(): Iterate up to MaxShardCount (32)
- IndexToShardId(): Iterate up to MaxShardCount (32)
- MinusParityShards(): Remove shards 10-31 instead of 10-13 (added note about Phase 2)
- Minus() shard size copy: Iterate up to MaxShardCount (32)
- resizeShardSizes(): Iterate up to MaxShardCount (32)
Without these changes:
- Custom EC ratios > 14 total shards would fail validation on startup
- Shards 14-31 would never be discovered or cleaned up
- ShardBits operations would miss shards >= 14
These changes are backward compatible - MaxShardCount (32) includes
the default TotalShardsCount (14), so existing 10+4 volumes work as before.
* fix: replace TotalShardsCount with MaxShardCount in critical data structures
Critical fixes for buffer allocations and loops that must support
custom EC ratios up to 32 shards:
Data Structures:
- store_ec.go:354: Buffer allocation for shard recovery (bufs array)
- topology_ec.go:14: EcShardLocations.Locations fixed array size
- command_ec_rebuild.go:268: EC shard map allocation
- command_ec_common.go:626: Shard-to-locations map allocation
Shard Discovery Loops:
- ec_task.go:378: Loop to find generated shard files
- ec_shard_management.go: All 8 loops that check/count EC shards
These changes are critical because:
1. Buffer allocations sized to 14 would cause index-out-of-bounds panics
when accessing shards 14-31
2. Fixed arrays sized to 14 would truncate shard location data
3. Loops limited to 0-13 would never discover/manage shards 14-31
Note: command_ec_encode.go:208 intentionally NOT changed - it creates
shard IDs to mount after encoding. In Phase 1 we always generate 14
shards, so this remains TotalShardsCount and will be made dynamic in
Phase 2 based on actual EC context.
Without these fixes, custom EC ratios > 14 total shards would cause:
- Runtime panics (array index out of bounds)
- Data loss (shards 14-31 never discovered/tracked)
- Incomplete shard management (missing shards not detected)
* refactor: move MaxShardCount constant to ec_encoder.go
Moved MaxShardCount from ec_volume_info.go to ec_encoder.go to group it
with other shard count constants (DataShardsCount, ParityShardsCount,
TotalShardsCount). This improves code organization and makes it easier
to understand the relationship between these constants.
Location: ec_encoder.go line 22, between TotalShardsCount and MinTotalDisks
* improve: add defensive programming and better error messages for EC
Code review improvements from CodeRabbit:
1. ShardBits Guardrails (ec_volume_info.go):
- AddShardId, RemoveShardId: Reject shard IDs >= MaxShardCount
- HasShardId: Return false for out-of-range shard IDs
- Prevents silent no-ops from bit shifts with invalid IDs
2. Future-Proof Regex (disk_location_ec.go):
- Updated regex from \.ec[0-9][0-9] to \.ec\d{2,3}
- Now matches .ec00 through .ec999 (currently .ec00-.ec31 used)
- Supports future increases to MaxShardCount beyond 99
3. Better Error Messages (volume_grpc_erasure_coding.go):
- Include valid range (1..32) in dataShards validation error
- Helps operators quickly identify the problem
4. Validation Before Save (volume_grpc_erasure_coding.go):
- Validate ECContext (DataShards > 0, ParityShards > 0, Total <= MaxShardCount)
- Log EC config being saved to .vif for debugging
- Prevents writing invalid configs to disk
These changes improve robustness and debuggability without changing
core functionality.
* fmt
* fix: critical bugs from code review + clean up comments
Critical bug fixes:
1. command_ec_rebuild.go: Fixed indentation causing compilation error
- Properly nested if/for blocks in registerEcNode
2. ec_shard_management.go: Fixed isComplete logic incorrectly using MaxShardCount
- Changed from MaxShardCount (32) back to TotalShardsCount (14)
- Default 10+4 volumes were being incorrectly reported as incomplete
- Missing shards 14-31 were being incorrectly reported as missing
- Fixed in 4 locations: volume completeness checks and getMissingShards
3. ec_volume_info.go: Fixed MinusParityShards removing too many shards
- Changed from MaxShardCount (32) back to TotalShardsCount (14)
- Was incorrectly removing shard IDs 10-31 instead of just 10-13
Comment cleanup:
- Removed Phase 1/Phase 2 references (development plan context)
- Replaced with clear statements about default 10+4 configuration
- SeaweedFS repo uses fixed 10+4 EC ratio, no phases needed
Root cause: Over-aggressive replacement of TotalShardsCount with MaxShardCount.
MaxShardCount (32) is the limit for buffer allocations and shard ID loops,
but TotalShardsCount (14) must be used for default EC configuration logic.
* fix: add defensive bounds checks and compute actual shard counts
Critical fixes from code review:
1. topology_ec.go: Add defensive bounds checks to AddShard/DeleteShard
- Prevent panic when shardId >= MaxShardCount (32)
- Return false instead of crashing on out-of-range shard IDs
2. command_ec_common.go: Fix doBalanceEcShardsAcrossRacks
- Was using hardcoded TotalShardsCount (14) for all volumes
- Now computes actual totalShardsForVolume from rackToShardCount
- Fixes incorrect rebalancing for volumes with custom EC ratios
- Example: 5+2=7 shards would incorrectly use 14 as average
These fixes improve robustness and prepare for future custom EC ratios
without changing current behavior for default 10+4 volumes.
Note: MinusParityShards and ec_task.go intentionally NOT changed for
seaweedfs repo - these will be enhanced in seaweed-enterprise repo
where custom EC ratio configuration is added.
* fmt
* style: make MaxShardCount type casting explicit in loops
Improved code clarity by explicitly casting MaxShardCount to the
appropriate type when used in loop comparisons:
- ShardId comparisons: Cast to ShardId(MaxShardCount)
- uint32 comparisons: Cast to uint32(MaxShardCount)
Changed in 5 locations:
- Minus() loop (line 90)
- ShardIds() loop (line 143)
- ToUint32Slice() loop (line 152)
- IndexToShardId() loop (line 219)
- resizeShardSizes() loop (line 248)
This makes the intent explicit and improves type safety readability.
No functional changes - purely a style improvement.
