swuferhong opened a new pull request, #3340:
URL: https://github.com/apache/fluss/pull/3340
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### Purpose
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Linked issue: close #3338
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Introduce a periodic disk-usage monitoring mechanism that proactively
rejects client writes when the TabletServer's data disk usage exceeds a
configurable high-water-mark ratio, preventing ENOSPC errors and potential data
corruption.
Key design decisions:
- Hysteresis state machine with a fixed 10% recovery gap to avoid rapid
lock/unlock oscillation (lock at limit, unlock at limit-0.10)
- Max-per-disk strategy: report the highest usage across all distinct
FileStores so a single full disk is never masked by other low-usage disks in
multi-disk deployments
- Only client-driven writes (appendLog/putKv) are rejected with a retriable
DiskWriteLockedException; follower replication is not blocked to preserve
replica consistency
- write-limit-ratio supports runtime dynamic reconfiguration via
ServerReconfigurable, with an immediate re-check on change
- Setting ratio to 1.0 completely disables the protection
New configuration:
- server.data-disk.write-limit-ratio (default 0.85, dynamic)
- server.data-disk.check-interval (default 30s)
New metrics:
- diskUsageRatio: current disk usage ratio [0.0, 1.0]
- diskWriteLocked: 1 when writes are being rejected, 0 otherwise
### Brief change log
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they address the issue -->
### Tests
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### API and Format
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### Documentation
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