Hazelcast Ringbuffer

Since Camel 2.16

Avalaible from Camel 2.16

The Hazelcast ringbuffer component is one of Camel Hazelcast Components which allows you to access Hazelcast ringbuffer. Ringbuffer is a distributed data structure where the data is stored in a ring-like structure. You can think of it as a circular array with a certain capacity.

Options

The Hazelcast Ringbuffer component supports 3 options, which are listed below.

Name Description Default Type

hazelcastInstance (advanced)

The hazelcast instance reference which can be used for hazelcast endpoint. If you don’t specify the instance reference, camel use the default hazelcast instance from the camel-hazelcast instance.

HazelcastInstance

hazelcastMode (advanced)

The hazelcast mode reference which kind of instance should be used. If you don’t specify the mode, then the node mode will be the default.

node

String

resolveProperty Placeholders (advanced)

Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders.

true

boolean

The Hazelcast Ringbuffer endpoint is configured using URI syntax:

hazelcast-ringbuffer:cacheName

with the following path and query parameters:

Path Parameters (1 parameters):

Name Description Default Type

cacheName

Required The name of the cache

String

Query Parameters (10 parameters):

Name Description Default Type

reliable (common)

Define if the endpoint will use a reliable Topic struct or not.

false

boolean

defaultOperation (producer)

To specify a default operation to use, if no operation header has been provided.

HazelcastOperation

hazelcastInstance (producer)

The hazelcast instance reference which can be used for hazelcast endpoint.

HazelcastInstance

hazelcastInstanceName (producer)

The hazelcast instance reference name which can be used for hazelcast endpoint. If you don’t specify the instance reference, camel use the default hazelcast instance from the camel-hazelcast instance.

String

synchronous (advanced)

Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).

false

boolean

concurrentConsumers (seda)

To use concurrent consumers polling from the SEDA queue.

1

int

onErrorDelay (seda)

Milliseconds before consumer continues polling after an error has occurred.

1000

int

pollTimeout (seda)

The timeout used when consuming from the SEDA queue. When a timeout occurs, the consumer can check whether it is allowed to continue running. Setting a lower value allows the consumer to react more quickly upon shutdown.

1000

int

transacted (seda)

If set to true then the consumer runs in transaction mode, where the messages in the seda queue will only be removed if the transaction commits, which happens when the processing is complete.

false

boolean

transferExchange (seda)

If set to true the whole Exchange will be transfered. If header or body contains not serializable objects, they will be skipped.

false

boolean

Spring Boot Auto-Configuration

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

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

The component supports 6 options, which are listed below.

Name Description Default Type

camel.component.hazelcast-ringbuffer.customizer.hazelcast-instance.enabled

Enable or disable the cache-manager customizer.

true

Boolean

camel.component.hazelcast-ringbuffer.customizer.hazelcast-instance.override

Configure if the cache manager eventually set on the component should be overridden by the customizer.

false

Boolean

camel.component.hazelcast-ringbuffer.enabled

Enable hazelcast-ringbuffer component

true

Boolean

camel.component.hazelcast-ringbuffer.hazelcast-instance

The hazelcast instance reference which can be used for hazelcast endpoint. If you don’t specify the instance reference, camel use the default hazelcast instance from the camel-hazelcast instance. The option is a com.hazelcast.core.HazelcastInstance type.

String

camel.component.hazelcast-ringbuffer.hazelcast-mode

The hazelcast mode reference which kind of instance should be used. If you don’t specify the mode, then the node mode will be the default.

node

String

camel.component.hazelcast-ringbuffer.resolve-property-placeholders

Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders.

true

Boolean

ringbuffer cache producer

The ringbuffer producer provides 5 operations: * add * readonceHead * readonceTail * remainingCapacity * capacity

Header Variables for the request message:

Name Type Description

CamelHazelcastOperationType

String

valid values are: put, get, removevalue, delete

CamelHazelcastObjectId

String

the object id to store / find your object inside the cache

Sample for put:

Java DSL:

from("direct:put")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.ADD))
.to(String.format("hazelcast-%sbar", HazelcastConstants.RINGBUFFER_PREFIX));

Spring DSL:

<route>
    <from uri="direct:put" />
    <log message="put.."/>
        <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" -->
    <setHeader headerName="hazelcast.operation.type">
        <constant>add</constant>
    </setHeader>
    <to uri="hazelcast-ringbuffer:foo" />
</route>

Sample for readonce from head:

Java DSL:

from("direct:get")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.READ_ONCE_HEAD))
.toF("hazelcast-%sbar", HazelcastConstants.RINGBUFFER_PREFIX)
.to("seda:out");