Solr

Since Camel 4.8

Only producer is supported

The Solr component allows you to interface with an Apache Solr server.

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-solr</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

URI format

solr://host[:port]/solr?[options]
solrs://host[:port]/solr?[options]
solrCloud://host[:port]/solr?[options]

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

At the component level, you set general and shared configurations that are, then, inherited by the endpoints. It is the highest configuration level.

For example, a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre-configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

You can configure components using:

  • the Component DSL.

  • in a configuration file (application.properties, *.yaml files, etc).

  • directly in the Java code.

Configuring Endpoint Options

You usually spend more time setting up endpoints because they have many options. These options help you customize what you want the endpoint to do. The options are also categorized into whether the endpoint is used as a consumer (from), as a producer (to), or both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java.

A good practice when configuring options is to use Property Placeholders.

Property placeholders provide a few benefits:

  • They help prevent using hardcoded urls, port numbers, sensitive information, and other settings.

  • They allow externalizing the configuration from the code.

  • They help the code to become more flexible and reusable.

The following two sections list all the options, firstly for the component followed by the endpoint.

Component Options

The Solr component supports 2 options, which are listed below.

Name Description Default Type

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

boolean

Endpoint Options

The Solr endpoint is configured using URI syntax:

solr:url

With the following path and query parameters:

Path Parameters (1 parameters)

Name Description Default Type

url (producer)

Required Hostname and port for the Solr server(s). Multiple hosts can be specified, separated with a comma. See the solrClient parameter for more information on the SolrClient used to connect to Solr.

String

Query Parameters (19 parameters)

Name Description Default Type

autoCommit (producer)

If true, each producer operation will be automatically followed by a commit.

false

boolean

connectionTimeout (producer)

Sets the connection timeout on the SolrClient.

Integer

defaultMaxConnectionsPerHost (producer)

Deprecated maxConnectionsPerHost on the underlying HttpConnectionManager.

Integer

httpClient (producer)

Sets the http client to be used by the solrClient. This is only applicable when solrClient is not set.

HttpClient

maxRetries (producer)

Deprecated Maximum number of retries to attempt in the event of transient errors.

Integer

maxTotalConnections (producer)

Deprecated maxTotalConnection on the underlying HttpConnectionManager.

Integer

requestHandler (producer)

Set the request handler to be used.

String

solrClient (producer)

Uses the provided solr client to connect to solr. When this parameter is not specified, camel applies the following rules to determine the SolrClient: 1) when zkHost or zkChroot (=zookeeper root) parameter is set, then the CloudSolrClient is used. 2) when multiple hosts are specified in the uri (separated with a comma), then the CloudSolrClient (uri scheme is 'solrCloud') or the LBHttpSolrClient (uri scheme is not 'solrCloud') is used. 3) when the solr operation is INSERT_STREAMING, then the ConcurrentUpdateSolrClient is used. 4) otherwise, the HttpSolrClient is used. Note: A CloudSolrClient should point to zookeeper endpoint(s); other clients point to Solr endpoint(s). The SolrClient can also be set via the exchange header 'CamelSolrClient'.

SolrClient

soTimeout (producer)

Sets the socket timeout on the SolrClient.

Integer

streamingQueueSize (producer)

Sets the queue size for the ConcurrentUpdateSolrClient.

10

int

streamingThreadCount (producer)

Sets the number of threads for the ConcurrentUpdateSolrClient.

2

int

lazyStartProducer (producer (advanced))

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

collection (CloudSolrClient)

Set the default collection for SolrCloud.

String

zkChroot (CloudSolrClient)

Set the chroot of the zookeeper connection (include the leading slash; e.g. '/mychroot').

String

zkHost (CloudSolrClient)

Set the ZooKeeper host(s) urls which the CloudSolrClient uses, e.g. zkHost=localhost:2181,localhost:2182. Optionally add the chroot, e.g. zkHost=localhost:2181,localhost:2182/rootformysolr. In case the first part of the url path (='contextroot') is set to 'solr' (e.g. 'localhost:2181/solr' or 'localhost:2181/solr/..'), then that path is not considered as zookeeper chroot for backward compatibility reasons (this behaviour can be overridden via zkChroot parameter).

String

allowCompression (HttpSolrClient)

Server side must support gzip or deflate for this to have any effect.

Boolean

followRedirects (HttpSolrClient)

Indicates whether redirects are used to get to the Solr server.

Boolean

password (security)

Sets password for basic auth plugin enabled servers.

String

username (security)

Sets username for basic auth plugin enabled servers.

String

Message Headers

The Solr component supports 5 message header(s), which is/are listed below:

Name Description Default Type

CamelSolrClient (producer)

Constant: CLIENT

The client.

SolrClient

CamelSolrCollection (producer)

Constant: COLLECTION

The collection to execute the request again.

String

SolrOperation (producer)

Constant: OPERATION

The operation to perform.

String

CamelSolrQueryString (producer)

Constant: QUERY_STRING

The query to execute.

String

Content-Type (producer)

Constant: CONTENT_TYPE

The content type.

String

Usage

Message Operations

The following Solr operations are currently supported. Set an exchange header with a key of SolrOperation and a value set to one of the following. Some operations also require the message body to be set.

  • INSERT

  • INSERT_STREAMING

Operation Message body Description

INSERT/INSERT_STREAMING

n/a

adds an index using message headers (must be prefixed with "SolrField.")

INSERT/INSERT_STREAMING

File

adds an index using the given File (using ContentStreamUpdateRequest)

INSERT/INSERT_STREAMING

SolrInputDocument

updates index based on the given SolrInputDocument

INSERT/INSERT_STREAMING

String XML

updates index based on the given XML (must follow SolrInputDocument format)

ADD_BEAN

bean instance

adds an index based on values in an annotated bean

ADD_BEANS

collection<bean>

adds index based on a collection of annotated bean

DELETE_BY_ID

index id to delete

delete a record by ID

DELETE_BY_QUERY

query string

delete a record by a query

COMMIT

n/a

performs a commit on any pending index changes

SOFT_COMMIT

n/a

performs a soft commit (without guarantee that Lucene index files are written to stable storage; useful for Near Real Time operations) on any pending index changes

ROLLBACK

n/a

performs a rollback on any pending index changes

OPTIMIZE

n/a

performs a commit on any pending index changes and then runs the optimize command (This command reorganizes the Solr index and might be a heavy task)

Example

Below is a simple INSERT, DELETE and COMMIT example

from("direct:insert")
    .setHeader(SolrConstants.OPERATION, constant(SolrConstants.OPERATION_INSERT))
    .setHeader(SolrConstants.FIELD + "id", body())
    .to("solr://localhost:8983/solr");

from("direct:delete")
    .setHeader(SolrConstants.OPERATION, constant(SolrConstants.OPERATION_DELETE_BY_ID))
    .to("solr://localhost:8983/solr");

from("direct:commit")
    .setHeader(SolrConstants.OPERATION, constant(SolrConstants.OPERATION_COMMIT))
    .to("solr://localhost:8983/solr");
<route>
    <from uri="direct:insert"/>
    <setHeader name="SolrOperation">
        <constant>INSERT</constant>
    </setHeader>
    <setHeader name="SolrField.id">
        <simple>${body}</simple>
    </setHeader>
    <to uri="solr://localhost:8983/solr"/>
</route>
<route>
    <from uri="direct:delete"/>
    <setHeader name="SolrOperation">
        <constant>DELETE_BY_ID</constant>
    </setHeader>
    <to uri="solr://localhost:8983/solr"/>
</route>
<route>
    <from uri="direct:commit"/>
    <setHeader name="SolrOperation">
        <constant>COMMIT</constant>
    </setHeader>
    <to uri="solr://localhost:8983/solr"/>
</route>

A client would simply need to pass a body message to the insert or delete routes and then call the commit route.

template.sendBody("direct:insert", "1234");
template.sendBody("direct:commit", null);
template.sendBody("direct:delete", "1234");
template.sendBody("direct:commit", null);

Querying Solr

The components provide a producer operation to query Solr.

For more information:

Solr Query Syntax

Spring Boot Auto-Configuration

When using solr with Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

<dependency>
  <groupId>org.apache.camel.springboot</groupId>
  <artifactId>camel-solr-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 3 options, which are listed below.

Name Description Default Type

camel.component.solr.autowired-enabled

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

Boolean

camel.component.solr.enabled

Whether to enable auto configuration of the solr component. This is enabled by default.

Boolean

camel.component.solr.lazy-start-producer

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

Boolean
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