{"results":[{"id":"pubsub-at-least-once-delivery","text":"Pub/Sub guarantees at-least-once delivery — duplicates are possible, and publish-side duplicates can have different `publishTime` values with the same `messageId`.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-attribute-key-no-goog-prefix","text":"Pub/Sub message attribute keys must not start with `goog` (reserved prefix).","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-bigquery-export-uses-topic-schema","text":"BigQuery export subscriptions can leverage the topic's schema, which is not available with the basic Dataflow template.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-dead-letter-attempt-count-approximate","text":"Delivery attempt counting for dead-letter topics is best-effort and approximate — messages may be forwarded after fewer or more attempts than configured.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-dead-letter-cross-project-supported","text":"Dead-letter topics can reside in a different project from the subscription using `--dead-letter-topic-project`.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-dead-letter-iam-requirements","text":"The Pub/Sub service account needs `roles/pubsub.publisher` on the dead-letter topic and `roles/pubsub.subscriber` on the source subscription, granted after creating the dead-letter topic.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-dead-letter-is-subscription-property","text":"Dead lettering is configured as a subscription property, not on the source topic.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-dead-letter-max-delivery-attempts-range","text":"The `max-delivery-attempts` parameter ranges from 5 (default) to 100.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-dead-letter-must-have-subscription","text":"The dead-letter topic must have its own subscription to consume forwarded messages; otherwise forwarded messages are lost.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-dead-letter-pull-inactive-counter-reset","text":"For pull subscriptions with inactive subscribers, the tracked delivery attempt count may reset to zero, causing more deliveries than the configured maximum.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-dead-letter-reliable-failure-handling","text":"Pub/Sub dead-letter topics provide reliable failure handling with configurable retry thresholds, proper IAM-gated routing, and cross-project dead-letter topic support.","truth_value":"OUT","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-delivery-guarantees-trade-throughput-for-correctness","text":"Pub/Sub delivery guarantees form a throughput-correctness trade-off spectrum: default at-least-once delivery is throughput-unconstrained but allows duplicates, adding ordering caps throughput at 1 MBps per key with cascading redelivery risk, and exactly-once narrows further to pull-only subscriptions — each stronger guarantee progressively shrinks the operational envelope, and composing ordering with exactly-once produces the most constrained mode (sequential in-order acks, thousands-per-second throughput).","truth_value":"OUT","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-exactly-once-default-ack-deadline-60s","text":"The default ack deadline for exactly-once subscriptions is 60 seconds (vs. the normal default).","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-exactly-once-end-to-end","text":"Pub/Sub provides exactly-once delivery guarantees from publisher to subscriber.","truth_value":"OUT","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-exactly-once-expired-ack-returns-invalid-argument","text":"Expired ack IDs return INVALID_ARGUMENT for exactly-once subscriptions (unlike regular subscriptions which return OK).","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-exactly-once-ordering-throughput-limit","text":"When combining ordering keys with exactly-once delivery, acks must be in-order and throughput drops to approximately thousands of messages per second.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-exactly-once-publish-duplicates-still-possible","text":"Publish-side duplicates can still occur even with exactly-once delivery enabled (publisher retries can cause duplicate messages).","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-exactly-once-pull-only","text":"Exactly-once delivery is only supported on pull subscriptions (including StreamingPull), not push or export subscriptions.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-exactly-once-regional-scope","text":"The exactly-once delivery guarantee only applies when subscribers connect to the service in the same region; multi-region subscribers may still receive duplicates.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null},{"id":"pubsub-exactly-once-with-ordering-production-ready","text":"Pub/Sub combining exactly-once delivery with ordering keys achieves sequential exactly-once processing — the gold standard for message processing guarantees.","truth_value":"OUT","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null}],"count":43,"limit":20,"offset":0}