Processing Reliability
Storm provides two types of guarantees when processing tuples for a Storm topology.
Table 4.3. Processing Guarantees
Guarantee | Description |
|---|---|
At least once | Reliable; Tuples are processed at least once, but may be processed more than once. Use when subsecond latency is required and for unordered idempotent operations. |
Exactly once | Reliable; Tuples are processed only once. (This feature requires the use of a Trident spout and the Trident API. For more information, see Trident Concepts.) |