org.apache.kafka.streams

Class KeyQueryMetadata

java.lang.Object

org.apache.kafka.streams.KeyQueryMetadata

public class KeyQueryMetadata
extends 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 NOTE: This is a point in time view.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 Summary

Fields

Modifier and Type	Field and Description
static KeyQueryMetadata	NOT_AVAILABLE Sentinel to indicate that the KeyQueryMetadata is currently unavailable.

Constructor Summary

Constructors

Constructor and Description
KeyQueryMetadata(HostInfo activeHost, Set<HostInfo> standbyHosts, int partition)

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
HostInfo	getActiveHost() Get the Active streams instance for given key
int	getPartition() Get the Store partition corresponding to the key.
Set<HostInfo>	getStandbyHosts() Get the Streams instances that host the key as standbys
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

NOT_AVAILABLE

public static final KeyQueryMetadata NOT_AVAILABLE

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

Constructor Detail

KeyQueryMetadata

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

Method Detail

getActiveHost

public HostInfo getActiveHost()

Get the Active streams instance for given key

Returns:

active instance's HostInfo

getStandbyHosts

public Set<HostInfo> getStandbyHosts()

Get the Streams instances that host the key as standbys

Returns:

set of standby HostInfo or a empty set, if no standbys are configured

getPartition

public int getPartition()

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