zhaoysg opened a new pull request, #11113:
URL: https://github.com/apache/seatunnel/pull/11113
…s advances ahead of prewrite replay (#11013)
The TiDB CDC source could silently drop row change events while `resolvedTs`
kept advancing, as reported in #11013. The root cause is in the CDC streaming
reader: `captureStreamingEvents` advanced `resolvedTs` to
`cdcClient.getMaxResolvedTs()` at the end of every batch, but the corresponding
commit/prewrite pair was consumed via `commits.pollFirstEntry().getValue()`
without verifying that the matching prewrite row had actually been buffered.
When a commit row arrived before its prewrite (which happens during region
split, rebalance, or under backpressure), the commit was discarded while
`resolvedTs` was still pushed forward past the commit timestamp, causing the
engine to skip subsequent real events at that timestamp without any error.
This commit fixes the issue and adds minimal diagnostic logging to help
users diagnose similar scenarios in the future.
Changes
-------
`TiDBSourceReader.captureStreamingEvents` / `flushRows`
- `flushRows` now returns a `safeResolvedTs`. If a commit row has no
matching prewrite row in `preWrites` yet, the function stops advancing
`resolvedTs` to the commit timestamp and holds the commit in the queue, so the
next batch can re-pair it with the late prewrite.
- `flushRows` now only `pollFirstEntry()`s a commit row after confirming its
prewrite is present, fixing the previous poll-then-leak behaviour.
- The batch loop distinguishes between a "no row right now" return from
`cdcClient.get()` and a "resolvedTs advanced but no row" case, and no longer
exits early when only `resolvedTs` moved.
`TiDBSourceReader.snapshotEvents`
- The snapshot scan no longer relies on a single `KVClient.scan` call over
the whole `keyRange`. It now uses a `RegionStoreClient` per region and walks
forward using `region.getEndKey()`, which is correct across region boundaries
and stops cleanly when the scan reaches the end of the requested key range.
- Adds `scannedCount` / `emittedCount` log on snapshot completion.
`TableKeyRangeUtils`
- `isRecordKey` now guards against short keys (`key.length > 10`) to avoid
`ArrayIndexOutOfBoundsException` on truncated payloads.
- Switches from Guava `ImmutableList` to JDK collections to keep the module
free of Guava dependencies on this hot path.
`TiDBSourceSplitEnumerator`
- Adds structured INFO logs for enumerator open, split enumeration, and
per-reader split assignment to make split distribution observable in production.
`TiDBSourceReader`
- Adds `[TiDB-CDC-DIAG]` streaming stats logging (every 10s or when a single
batch exceeds 1s) exposing `resolvedLagMs`, polled/emitted/committed counters,
and pull/flush/emit latencies. This is the primary signal users can use to
detect a prewrite/commit imbalance in the future.
Fixes #11013
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