Package org.apache.storm.kafka.spout

Enum KafkaSpoutConfig.ProcessingGuarantee

java.lang.Object
java.lang.Enum<KafkaSpoutConfig.ProcessingGuarantee>
org.apache.storm.kafka.spout.KafkaSpoutConfig.ProcessingGuarantee
All Implemented Interfaces:
Serializable, Comparable<KafkaSpoutConfig.ProcessingGuarantee>, java.lang.constant.Constable
Enclosing class:
KafkaSpoutConfig<K,V>
@Unstable public static enum KafkaSpoutConfig.ProcessingGuarantee extends Enum<KafkaSpoutConfig.ProcessingGuarantee>
This enum controls when the tuple with the ConsumerRecord for an offset is marked as processed, i.e. when the offset can be committed to Kafka. The default value is AT_LEAST_ONCE. The commit interval is controlled by KafkaSpoutConfig.getOffsetsCommitPeriodMs(), if the mode commits on an interval. NO_GUARANTEE may be removed in a later release without warning, we're still evaluating whether it makes sense to keep.

  • Enum Constant Details

    • AT_LEAST_ONCE

      public static final KafkaSpoutConfig.ProcessingGuarantee AT_LEAST_ONCE
      An offset is ready to commit only after the corresponding tuple has been processed and acked (at least once). If a tuple fails or times out it will be re-emitted, as controlled by the KafkaSpoutRetryService. Commits synchronously on the defined interval.

    • AT_MOST_ONCE

      public static final KafkaSpoutConfig.ProcessingGuarantee AT_MOST_ONCE
      Every offset will be synchronously committed to Kafka right after being polled but before being emitted to the downstream components of the topology. The commit interval is ignored. This mode guarantees that the offset is processed at most once by ensuring the spout won't retry tuples that fail or time out after the commit to Kafka has been done

    • NO_GUARANTEE

      public static final KafkaSpoutConfig.ProcessingGuarantee NO_GUARANTEE
      The polled offsets are ready to commit immediately after being polled. The offsets are committed periodically, i.e. a message may be processed 0, 1 or more times. This behavior is similar to setting enable.auto.commit=true in the consumer, but allows the spout to control when commits occur. Commits asynchronously on the defined interval.

  • Method Details

    • values

      public static KafkaSpoutConfig.ProcessingGuarantee[] values()
      Returns an array containing the constants of this enum type, in the order they are declared.
      Returns:
      an array containing the constants of this enum type, in the order they are declared

    • valueOf

      public static KafkaSpoutConfig.ProcessingGuarantee valueOf(String name)
      Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
      Parameters:
      name - the name of the enum constant to be returned.
      Returns:
      the enum constant with the specified name
      Throws:
      IllegalArgumentException - if this enum type has no constant with the specified name
      NullPointerException - if the argument is null