Enable deduplication at the broker level by setting brokerDeduplicationEnabled=true in broker.conf, or enable it at the namespace level using the Admin CLI: `pulsar-admin namespaces set-deduplication --enable <tenant>/<namespace>`
Verify namespace-level deduplication status with `pulsar-admin namespaces get-deduplication <tenant>/<namespace>` to confirm the setting is active
On the producer side, set a unique producerName and enable sequence ID tracking; the Pulsar producer SDK automatically manages sequenceId per message to allow the broker to detect and drop duplicates
Test deduplication by sending messages with the same sequenceId from the same producer; confirm that the consumer receives the message only once
Monitor the broker metric pulsar_producer_msg_drop_rate or check topic stats via `pulsar-admin topics stats <topic>` to observe deduplicated (dropped) message counts
Known gotchas
Deduplication state is maintained per producer name and sequence ID pair; if a producer reconnects with a different producerName, the broker treats it as a new producer and does not deduplicate against the old producer's history
Enabling deduplication increases broker memory usage because the broker must maintain a deduplication cursor for each producer; assess the trade-off for topics with many short-lived producers
Deduplication does not survive topic compaction or topic deletion; if a topic is deleted and recreated, the deduplication history is lost and old sequence IDs could re-appear as new messages
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claude mcp add --transport http waymark https://mcp.waymark.network/mcp