Offsets & Recovery

What is stored

The source connector keeps one offset per SObject (source partition {"sobject": "<name>"}):

{
  "offsetVersion": "1",
  "mode": "EVENT_DRIVEN",
  "replayId": "AAAAAAAABDI=",
  "probeReplayId": "AAAAAAAABCg=",
  "snapshotCompletionTimestamp": 1767200000000,
  "lastSystemModstamp": "2026-07-01T00:00:00.000Z",
  "commitTimestamp": 1767201234567
}

• replayId — the Pub/Sub position (opaque bytes, base64), resumed with replay_preset=CUSTOM.
• probeReplayId — the pre-snapshot probe used for the handoff; kept until the first live event is processed.
• lastSystemModstamp — the polling-mode cursor.
• commitTimestamp — the last CDC commit seen; the watermark for gap resync.

The legacy CometD source stores {"replayId": <long>} per channel.

Recovery scenarios

Scenario	Behaviour
Worker restart / rebalance	Resume from stored offsets; no action needed
Downtime < 72h (event-driven)	Replay from replayId — no loss, possible duplicates
Downtime > 72h / expired replayId	sf.gap.recovery: resync (incremental Bulk re-sync from the watermark − buffer), latest (accept loss), or fail
CDC gap event (GAP_*)	Affected record Ids re-queried via REST and re-emitted
CDC overflow (GAP_OVERFLOW)	Per sf.gap.recovery (overflow doesn't identify records)
Restart mid-snapshot	Snapshot restarts from the beginning (at-least-once); the original probe replayId is retained so the handoff still misses nothing

Resetting offsets

To re-consume from scratch, delete the connector, remove its offsets, and re-create it. With Kafka Connect ≥ 3.6 you can use the offsets REST API:

# stop the connector, then
curl -X DELETE localhost:8083/connectors/salesforce-source/offsets

Per-SObject resets are possible by patching only that partition's offset. After a reset, the cold-start position follows sf.event.start (latest or all) and, if enabled, a fresh snapshot runs first.