Version: 1.0.4

Storm Solr Integration

Storm and Trident integration for Apache Solr. This package includes a bolt and a trident state that enable a Storm topology stream the contents of storm tuples to index Solr collections.

Index Storm tuples into a Solr collection

The The bolt and trident state provided use one of the supplied mappers to build a SolrRequest object that is responsible for making the update calls to Solr, thus updating the index of the collection specified.

Usage Examples

In this section we provide some simple code snippets on how to build Storm and Trident topologies to index Solr. In subsequent sections we describe in detail the two key components of the Storm Solr integration, the SolrUpdateBolt, and the Mappers, SolrFieldsMapper, and SolrJsonMapper.

Storm Bolt With JSON Mapper and Count Based Commit Strategy

    new SolrUpdateBolt(solrConfig, solrMapper, solrCommitStgy)

    // zkHostString for Solr 'gettingstarted' example
    SolrConfig solrConfig = new SolrConfig("127.0.0.1:9983");

    // JSON Mapper used to generate 'SolrRequest' requests to update the "gettingstarted" Solr collection with JSON content declared the tuple field with name "JSON"
    SolrMapper solrMapper = new SolrJsonMapper.Builder("gettingstarted", "JSON").build(); 

    // Acks every other five tuples. Setting to null acks every tuple
    SolrCommitStrategy solrCommitStgy = new CountBasedCommit(5);          

Trident Topology With Fields Mapper

    new SolrStateFactory(solrConfig, solrMapper);

    // zkHostString for Solr 'gettingstarted' example
    SolrConfig solrConfig = new SolrConfig("127.0.0.1:9983");

    /* Solr Fields Mapper used to generate 'SolrRequest' requests to update the "gettingstarted" Solr collection. The Solr index is updated using the field values of the tuple fields that match static or dynamic fields declared in the schema object build using schemaBuilder */ 
    SolrMapper solrMapper = new SolrFieldsMapper.Builder(schemaBuilder, "gettingstarted").build();

    // builds the Schema object from the JSON representation of the schema as returned by the URL http://localhost:8983/solr/gettingstarted/schema/ 
    SchemaBuilder schemaBuilder = new RestJsonSchemaBuilder("localhost", "8983", "gettingstarted")

SolrUpdateBolt

SolrUpdateBolt streams tuples directly into Apache Solr. The Solr index is updated usingSolrRequest requests. The SolrUpdateBolt is configurable using implementations of SolrConfig, SolrMapper, and optionally SolrCommitStrategy.

The data to stream onto Solr is extracted from the tuples using the strategy defined in the SolrMapper implementation.

The SolrRquest can be sent every tuple, or according to a strategy defined by SolrCommitStrategy implementations. If a SolrCommitStrategy is in place and one of the tuples in the batch fails, the batch is not committed, and all the tuples in that batch are marked as Fail, and retried. On the other hand, if all tuples succeed, the SolrRequest is committed and all tuples are successfully acked.

SolrConfig is the class containing Solr configuration to be made available to Storm Solr bolts. Any configuration needed in the bolts should be put in this class.

SolrMapper

SorlMapper implementations define the strategy to extract information from the tuples. The public method toSolrRequest receives a tuple or a list of tuples and returns a SolrRequest object that is used to update the Solr index.

SolrJsonMapper

The SolrJsonMapper creates a Solr update request that is sent to the URL endpoint defined by Solr as the resource destination for requests in JSON format.

To create a SolrJsonMapper the client must specify the name of the collection to update as well as the tuple field that contains the JSON object used to update the Solr index. If the tuple does not contain the field specified, a SolrMapperException will be thrown when the method toSolrRequestis called. If the field exists, its value can either be a String with the contents in JSON format, or a Java object that will be serialized to JSON

Code snippet illustrating how to create a SolrJsonMapper object to update the gettingstarted Solr collection with JSON content declared in the tuple field with name "JSON" java SolrMapper solrMapper = new SolrJsonMapper.Builder("gettingstarted", "JSON").build();

SolrFieldsMapper

The SolrFieldsMapper creates a Solr update request that is sent to the Solr URL endpoint that handles the updates of SolrInputDocument objects.

To create a SolrFieldsMapper the client must specify the name of the collection to update as well as the SolrSchemaBuilder. The Solr Schema is used to extract information about the Solr schema fields and corresponding types. This metadata is used to get the information from the tuples. Only tuple fields that match a static or dynamic Solr fields are added to the document. Tuple fields that do not match the schema are not added to the SolrInputDocument being prepared for indexing. A debug log message is printed for the tuple fields that do not match the schema and hence are not indexed.

The SolrFieldsMapper supports multivalue fields. A multivalue tuple field must be tokenized. The default token is |. Any arbitrary token can be specified by calling the method org.apache.storm.solr.mapper.SolrFieldsMapper.Builder.setMultiValueFieldToken that is part of the SolrFieldsMapper.Builder builder class.

Code snippet illustrating how to create a SolrFieldsMapper object to update the gettingstarted Solr collection. The multivalue field separates each value with the token % instead of the default | . To use the default token you can ommit the call to the method setMultiValueFieldToken.

    new SolrFieldsMapper.Builder(
            new RestJsonSchemaBuilder("localhost", "8983", "gettingstarted"), "gettingstarted")
                .setMultiValueFieldToken("%").build();

Build And Run Bundled Examples

To be able to run the examples you must first build the java code in the package storm-solr, and then generate an uber jar with all the dependencies.

Build the Storm Apache Solr Integration Code

mvn clean install -f REPO_HOME/storm/external/storm-solr/pom.xml

Use the Maven Shade Plugin to Build the Uber Jar

Add the following to REPO_HOME/storm/external/storm-solr/pom.xml

 <plugin>
     <groupId>org.apache.maven.plugins</groupId>
     <artifactId>maven-shade-plugin</artifactId>
     <version>2.4.1</version>
     <executions>
         <execution>
             <phase>package</phase>
             <goals>
                 <goal>shade</goal>
             </goals>
             <configuration>
                 <transformers>
                     <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                         <mainClass>org.apache.storm.solr.topology.SolrJsonTopology</mainClass>
                     </transformer>
                 </transformers>
             </configuration>
         </execution>
     </executions>
</plugin>

create the uber jar by running the commmand:

mvn package -f REPO_HOME/storm/external/storm-solr/pom.xml

This will create the uber jar file with the name and location matching the following pattern:

REPO_HOME/storm/external/storm/target/storm-solr-0.11.0-SNAPSHOT.jar

Run Examples

Copy the file REPO_HOME/storm/external/storm-solr/target/storm-solr-0.11.0-SNAPSHOT.jar to STORM_HOME/extlib

The code examples provided require that you first run the Solr gettingstarted example

Run Storm Topology

STORM_HOME/bin/storm jar REPO_HOME/storm/external/storm-solr/target/storm-solr-0.11.0-SNAPSHOT-tests.jar org.apache.storm.solr.topology.SolrFieldsTopology

STORM_HOME/bin/storm jar REPO_HOME/storm/external/storm-solr/target/storm-solr-0.11.0-SNAPSHOT-tests.jar org.apache.storm.solr.topology.SolrJsonTopology

Run Trident Topology

STORM_HOME/bin/storm jar REPO_HOME/storm/external/storm-solr/target/storm-solr-0.11.0-SNAPSHOT-tests.jar org.apache.storm.solr.trident.SolrFieldsTridentTopology

STORM_HOME/bin/storm jar REPO_HOME/storm/external/storm-solr/target/storm-solr-0.11.0-SNAPSHOT-tests.jar org.apache.storm.solr.trident.SolrJsonTridentTopology

Verify Results

The aforementioned Storm and Trident topologies index the Solr gettingstarted collection with objects that have the following id pattern:

*id_fields_test_val* for SolrFieldsTopology and SolrFieldsTridentTopology

*json_test_val* for SolrJsonTopology and SolrJsonTridentTopology

Querying Solr for these patterns, you will see the values that have been indexed by the Storm Apache Solr integration:

curl -X GET -H "Content-type:application/json" -H "Accept:application/json" http://localhost:8983/solr/gettingstarted_shard1_replica2/select?q=*id_fields_test_val*&wt=json&indent=true

curl -X GET -H "Content-type: application/json" -H "Accept: application/json" http://localhost:8983/solr/gettingstarted_shard1_replica2/select?q=*id_fields_test_val*&wt=json&indent=true

You can also see the results by opening the Apache Solr UI and pasting the id pattern in the q textbox in the queries page

http://localhost:8983/solr/#/gettingstarted_shard1_replica2/query