Pulsar: acknowledgment-strategy choice (individual / cumulative / batched) (#3180)#3202
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…ched) (#3180) Pulsar analogue of the Kafka CommitMode overhaul (#3150). Adds a per-listener ack strategy: - Individual (default): ack each message as it completes (unchanged behavior). - Cumulative: one ack confirms everything up to a point. Exclusive/Failover only — configuring it on a Shared/Key_Shared subscription throws a clear error at startup. Because the buffered listener completes out of order, the cumulative ack only ever advances to the highest CONTIGUOUS-completed message (PulsarAckHandler tracks in-flight ids and the completed set), so it never acks a still-in-flight message — no silent message loss. - Batched: individual acks flushed by count or interval; no ordering constraint, safe for any subscription type. New PulsarAckHandler encapsulates the three modes; PulsarListener tracks receipts and routes CompleteAsync through it (retry-consumer messages always ack individually) and flushes batched acks on shutdown. Config via AcknowledgeIndividually()/AcknowledgeCumulative()/AcknowledgeInBatches(...). Tests: deterministic handler unit tests (individual, batched-by-count, cumulative out-of-order watermark + in-order), startup rejection of cumulative-on-Shared, and an end-to-end batched delivery test. Docs updated. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This was referenced Jun 23, 2026
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This was referenced Jun 29, 2026
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Part of the Pulsar re-evaluation epic #3176. Fixes #3180. Builds on #3179.
The Pulsar analogue of the Kafka
CommitModeoverhaul (#3150). Adds a per-listener acknowledgment strategy.Strategies
Cumulative ordering safety (the correctness-sensitive bit)
Wolverine's buffered listener completes messages out of order. A naive cumulative ack of a later message would confirm earlier, still-in-flight ones — silent message loss.
PulsarAckHandlertracks in-flight ids and the completed set, and only ever advances the cumulative ack to the highest contiguous-completed message, so it never acks past in-flight work. This is proven deterministically by a unit test (complete 2 and 3 while 1 is in flight → no ack; complete 1 → single cumulative ack jumps to 3).Changes
PulsarAckStrategyenum +PulsarAckHandler(encapsulates all three modes, watermark logic, batch flush + shutdown flush).PulsarListenertracks receipts and routesCompleteAsyncthrough the handler (retry-consumer messages always ack individually); startup validation for cumulative-on-Shared.PulsarListenerConfiguration.AcknowledgeIndividually() / AcknowledgeCumulative() / AcknowledgeInBatches(size, interval).Tests
Deterministic handler unit tests (individual; batched-by-count; cumulative out-of-order watermark + in-order), startup rejection of cumulative-on-Shared, and an end-to-end batched delivery test. Docs updated.
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