Package org.apache.kafka.streams

Class KeyQueryMetadata

java.lang.Object
org.apache.kafka.streams.KeyQueryMetadata
public class KeyQueryMetadataextends Object
Represents all the metadata related to a key, where a particular key resides in a KafkaStreams application. It contains the active HostInfo and a set of standby HostInfos, denoting the instances where the key resides. It also contains the partition number where the key belongs, which could be useful when used in conjunction with other APIs. e.g: Relating with lags for that store partition. NOTE: This is a point in time view. It may change as rebalances happen.

  • Field Details

    • NOT_AVAILABLE

      public static final KeyQueryMetadata NOT_AVAILABLE
      Sentinel to indicate that the KeyQueryMetadata is currently unavailable. This can occur during rebalance operations.

  • Constructor Details

    • KeyQueryMetadata

      public KeyQueryMetadata(HostInfo activeHost, Set<HostInfo> standbyHosts, int partition)

  • Method Details

    • activeHost

      public HostInfo activeHost()
      Get the active Kafka Streams instance for given key.
      Returns:
      active instance's HostInfo

    • standbyHosts

      public Set<HostInfo> standbyHosts()
      Get the Kafka Streams instances that host the key as standbys.
      Returns:
      set of standby HostInfo or an empty set, if no standbys are configured

    • partition

      public int partition()
      Get the store partition corresponding to the key.
      Returns:
      store partition number

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object