io.kurrent.dbclient

Class NamedConsumerStrategy

java.lang.Object

io.kurrent.dbclient.NamedConsumerStrategy

public class NamedConsumerStrategy
extends java.lang.Object

Named consumer strategies for use with persistent subscriptions.

Field Summary

Fields

Modifier and Type	Field and Description
static NamedConsumerStrategy	DISPATCH_TO_SINGLE Distributes events to a single client until the buffer size is reached.
static NamedConsumerStrategy	PINNED For use with an indexing projection such as the system $by_category projection.
static NamedConsumerStrategy	PINNED_BY_CORRELATION This is similar to the Pinned strategy, but instead of using the source stream id to bucket the messages, it distributes the events based on the event's correlationId.
static NamedConsumerStrategy	ROUND_ROBIN Distributes events to all client evenly.

Method Summary

Modifier and Type	Method and Description
boolean	isDispatchToSingle() Checks if it's a DispatchToSingle strategy.
boolean	isNamed(java.lang.String named) Checks if the strategy's name matches the string passed as a parameter.
boolean	isPinned() Checks if it's a Pinned strategy.
boolean	isPinnedByCorrelation() Checks if it's a PinnedByCorrelation strategy.
boolean	isRoundRobin() Checks if it's a RoundRobin strategy.
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DISPATCH_TO_SINGLE

public static final NamedConsumerStrategy DISPATCH_TO_SINGLE

Distributes events to a single client until the buffer size is reached. After which the next client is selected in a round-robin style, and the process is repeated.

ROUND_ROBIN

public static final NamedConsumerStrategy ROUND_ROBIN

Distributes events to all client evenly. If the client buffer-size is reached, the client is ignored until events are (not) acknowledged.

PINNED

public static final NamedConsumerStrategy PINNED

For use with an indexing projection such as the system $by_category projection. KurrentDB inspects event for its source stream id, hashing the id to one of 1024 buckets assigned to individual clients. When a client disconnects, its buckets are assigned to other clients. When a client connects, it is assigned some existing buckets. This naively attempts to maintain a balanced workload. The main goal of this strategy is to decrease the likelihood of concurrency and ordering issues while maintaining load balancing. This not a guarantee, and you should handle the usual ordering and concurrency issues.

PINNED_BY_CORRELATION

public static final NamedConsumerStrategy PINNED_BY_CORRELATION

This is similar to the Pinned strategy, but instead of using the source stream id to bucket the messages, it distributes the events based on the event's correlationId.

Method Detail

isDispatchToSingle

public boolean isDispatchToSingle()

Checks if it's a DispatchToSingle strategy.

isRoundRobin

public boolean isRoundRobin()

Checks if it's a RoundRobin strategy.

isPinned

public boolean isPinned()

Checks if it's a Pinned strategy.

isPinnedByCorrelation

public boolean isPinnedByCorrelation()

Checks if it's a PinnedByCorrelation strategy.

isNamed

public boolean isNamed(java.lang.String named)

Checks if the strategy's name matches the string passed as a parameter.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object