org.apache.solr.client.solrj.routing

Class AffinityReplicaListTransformer

java.lang.Object

org.apache.solr.client.solrj.routing.AffinityReplicaListTransformer

All Implemented Interfaces:

ReplicaListTransformer

public class AffinityReplicaListTransformer
extends Object
implements ReplicaListTransformer

Allows better caching by establishing deterministic evenly-distributed replica routing preferences according to either explicitly configured hash routing parameter, or the hash of a query parameter (configurable, usually related to the main query).

Method Summary

Modifier and Type	Method and Description
static ReplicaListTransformer	getInstance(String dividendParam, String hashParam, SolrParams requestParams)
void	transform(List<?> choices) Transforms the passed in list of choices.

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static ReplicaListTransformer getInstance(String dividendParam,
                                                 String hashParam,
                                                 SolrParams requestParams)

Parameters:

dividendParam - int param to be used directly for mod-based routing

hashParam - String param to be hashed into an int for mod-based routing

requestParams - the parameters of the Solr request

Returns:

null if specified routing vals are not able to be parsed properly

transform

public void transform(List<?> choices)

Description copied from interface: ReplicaListTransformer

Transforms the passed in list of choices. Transformations can include (but are not limited to) reordering of elements (e.g. via shuffling) and removal of elements (i.e. filtering).

Specified by:

transform in interface ReplicaListTransformer

Parameters:

choices - - a list of choices to transform, typically the choices are Replica objects but choices can also be String objects such as URLs passed in via the ShardParams.SHARDS parameter.