Kudu

Since Camel 3.0

Only producer is supported

The Kudu component supports storing and retrieving data from/to Apache Kudu, a free and open source column-oriented data store of the Apache Hadoop ecosystem.

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

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

Prerequisites

You must have a valid Kudu instance running. More information is available at Apache Kudu.

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 Kudu component supports 3 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

kuduClient (advanced)

Autowired To use an existing Kudu client instance, instead of creating a client per endpoint. This allows you to customize various aspects to the client configuration.

KuduClient

Endpoint Options

The Kudu endpoint is configured using URI syntax:

kudu:host:port/tableName

With the following path and query parameters:

Path Parameters (3 parameters)

Name Description Default Type

host (common)

Required Host of the server to connect to.

String

port (common)

Required Port of the server to connect to.

String

tableName (common)

Table to connect to.

String

Query Parameters (2 parameters)

Name Description Default Type

operation (producer)

Operation to perform.

Enum values:

  • INSERT

  • DELETE

  • UPDATE

  • UPSERT

  • CREATE_TABLE

  • SCAN

KuduOperations

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

Message Headers

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

Name Description Default Type

CamelKuduSchema (producer)

Constant: CAMEL_KUDU_SCHEMA

The schema.

Schema

CamelKuduTableOptions (producer)

Constant: CAMEL_KUDU_TABLE_OPTIONS

The create table options.

CreateTableOptions

CamelKuduScanColumnNames (producer)

Constant: CAMEL_KUDU_SCAN_COLUMN_NAMES

The projected column names for scan operation.

List

CamelKuduScanPredicate (producer)

Constant: CAMEL_KUDU_SCAN_PREDICATE

The predicate for scan operation.

KuduPredicate

CamelKuduScanLimit (producer)

Constant: CAMEL_KUDU_SCAN_LIMIT

The limit on the number of rows for scan operation.

long

Usage

Input Body formats

Insert, delete, update, and upsert

The input body format has to be a java.util.Map<String, Object>. This map will represent a row of the table whose elements are columns, where the key is the column name and the value is the value of the column.

Output Body formats

Scan

The output body format will be a java.util.List<java.util.Map<String, Object>>. Each element of the list will be a different row of the table. Each row is a Map<String, Object> whose elements will be each pair of column name and column value for that row.

Spring Boot Auto-Configuration

When using kudu 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-kudu-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 4 options, which are listed below.

Name Description Default Type

camel.component.kudu.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.kudu.enabled

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

Boolean

camel.component.kudu.kudu-client

To use an existing Kudu client instance, instead of creating a client per endpoint. This allows you to customize various aspects to the client configuration. The option is a org.apache.kudu.client.KuduClient type.

KuduClient

camel.component.kudu.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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