com.hazelcast.jet.elastic

Class ElasticSourceBuilder<T>

java.lang.Object

com.hazelcast.jet.elastic.ElasticSourceBuilder<T>

Type Parameters:

T - type of the output of the mapping function from SearchHit -> T

public final class ElasticSourceBuilder<T>
extends Object

Builder for Elasticsearch source which reads data from Elasticsearch and converts SearchHits using provided mapToItemFn

Usage:

 BatchSource<String> source = new ElasticSourceBuilder<String>()
   .clientFn(() -> client(host, port))
   .searchRequestFn(() -> new SearchRequest("my-index"))
   .mapToItemFn(SearchHit::getSourceAsString)
   .build();

 BatchStage<String> stage = p.readFrom(source);
 

Requires clientFn(SupplierEx), searchRequestFn(SupplierEx) and mapToItemFn(FunctionEx).

Since:

Jet 4.2

Constructor Summary

Constructors

Constructor and Description
ElasticSourceBuilder()

Method Summary

Modifier and Type	Method and Description
BatchSource<T>	build() Build Elasticsearch BatchSource with supplied parameters
ElasticSourceBuilder<T>	clientFn(SupplierEx<org.elasticsearch.client.RestClientBuilder> clientFn) Set the client supplier function
ElasticSourceBuilder<T>	enableCoLocatedReading() Enable co-located reading Jet cluster member must run exactly on the same nodes as Elastic cluster.
ElasticSourceBuilder<T>	enableSlicing() Enable slicing
<T_NEW> ElasticSourceBuilder<T_NEW>	mapToItemFn(FunctionEx<? super org.elasticsearch.search.SearchHit,T_NEW> mapToItemFn) Set the function to map SearchHit to a pipeline item
ElasticSourceBuilder<T>	retries(int retries) Number of retries the connector will do in addition to Elastic client retries Elastic client tries to connect to a node only once for each request.
ElasticSourceBuilder<T>	scrollKeepAlive(String scrollKeepAlive) Set the keepAlive for Elastic search scroll
ElasticSourceBuilder<T>	searchRequestFn(SupplierEx<org.elasticsearch.action.search.SearchRequest> searchRequestFn) Set the search request supplier function

Methods inherited from class java.lang.Object

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

Constructor Detail

ElasticSourceBuilder

public ElasticSourceBuilder()

Method Detail

build

@Nonnull
public BatchSource<T> build()

Build Elasticsearch BatchSource with supplied parameters

Returns:

configured source which is to be used in the pipeline

clientFn

@Nonnull
public ElasticSourceBuilder<T> clientFn(@Nonnull
                                                 SupplierEx<org.elasticsearch.client.RestClientBuilder> clientFn)

Set the client supplier function

The connector uses the returned instance to access Elasticsearch. Also see ElasticClients for convenience factory methods.

For example, to provide an authenticated client:

 builder.clientFn(() -> client(host, port, username, password))
 

This parameter is required.

Parameters:

clientFn - supplier function returning configured Elasticsearch REST client

searchRequestFn

@Nonnull
public ElasticSourceBuilder<T> searchRequestFn(@Nonnull
                                                        SupplierEx<org.elasticsearch.action.search.SearchRequest> searchRequestFn)

Set the search request supplier function

The connector executes this search request to retrieve documents from Elasticsearch.

For example, to create SearchRequest limited to an index `logs`:

 builder.searchRequestFn(() -> new SearchRequest("logs"))
 

This parameter is required.

Parameters:

searchRequestFn - search request supplier function

mapToItemFn

@Nonnull
public <T_NEW> ElasticSourceBuilder<T_NEW> mapToItemFn(@Nonnull
                                                                FunctionEx<? super org.elasticsearch.search.SearchHit,T_NEW> mapToItemFn)

Set the function to map SearchHit to a pipeline item

For example, to map a SearchHit to a value of a field `productId`:

 builder.mapToItemFn(hit -> (String) hit.getSourceAsMap().get("productId"))
 

This parameter is required.

Parameters:

mapToItemFn - maps search hits to output items

enableSlicing

@Nonnull
public ElasticSourceBuilder<T> enableSlicing()

Enable slicing

Number of slices is equal to globalParallelism (localParallelism * numberOfNodes) when only slicing is enabled. When co-located reading is enabled as well then number of slices for particular node is equal to localParallelism.

Use this option to read from multiple shards in parallel. It can also be used on single shard, but it may increase initial latency. See Elastic documentation for Sliced Scroll for details.

enableCoLocatedReading

@Nonnull
public ElasticSourceBuilder<T> enableCoLocatedReading()

Enable co-located reading Jet cluster member must run exactly on the same nodes as Elastic cluster.

scrollKeepAlive

@Nonnull
public ElasticSourceBuilder<T> scrollKeepAlive(@Nonnull
                                                        String scrollKeepAlive)

Set the keepAlive for Elastic search scroll

The value must be in Elastic time unit format, e.g. 500ms for 500 milliseconds, 30s for 30 seconds, 5m for 5 minutes. See SearchRequest.scroll(String).

Parameters:

scrollKeepAlive - keepAlive value, this must be high enough to process all results from a single scroll, default value 1m

retries

@Nonnull
public ElasticSourceBuilder<T> retries(int retries)

Number of retries the connector will do in addition to Elastic client retries Elastic client tries to connect to a node only once for each request. When a request fails the node is marked dead and is not retried again for the request. This causes problems with single node clusters or in a situation where whole cluster becomes unavailable at the same time (e.g. due to a network issue). The initial delay is 2s, increasing by factor of 2 with each retry (4s, 8s, 16s, ..).

Parameters:

retries - number of retries, defaults to 5