Hazelcast Replicated Map

Since Camel 2.16

Both producer and consumer are supported

The Hazelcast instance component is one of Camel Hazelcast Components which allows you to consume join/leave events of the cache instance in the cluster. A replicated map is a weakly consistent, distributed key-value data structure with no data partition.

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

The component level is the highest level which holds general and common configurations that are inherited by the endpoints. 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.

Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.

Configuring Endpoint Options

Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for 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, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.

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

Component Options

The Hazelcast Replicated Map component supports 5 options, which are listed below.

Name Description Default Type

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

boolean

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

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

Endpoint Options

The Hazelcast Replicated Map endpoint is configured using URI syntax:

hazelcast-replicatedmap:cacheName

with the following path and query parameters:

Path Parameters (1 parameters)

Name Description Default Type

cacheName (common)

Required The name of the cache.

String

Query Parameters (8 parameters)

Name Description Default Type

defaultOperation (common)

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

Enum values:

  • put

  • delete

  • get

  • update

  • query

  • getAll

  • clear

  • putIfAbsent

  • addAll

  • removeAll

  • retainAll

  • evict

  • evictAll

  • valueCount

  • containsKey

  • containsValue

  • getKeys

  • removeValue

  • increment

  • decrement

  • setValue

  • destroy

  • compareAndSet

  • getAndAdd

  • add

  • offer

  • peek

  • poll

  • remainingCapacity

  • drainTo

  • removeIf

  • take

  • publish

  • readOnceHead

  • readOnceTail

  • capacity

HazelcastOperation

hazelcastConfigUri (common)

Hazelcast configuration file.

String

hazelcastInstance (common)

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

HazelcastInstance

hazelcastInstanceName (common)

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

bridgeErrorHandler (consumer (advanced))

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

boolean

exceptionHandler (consumer (advanced))

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

ExceptionHandler

exchangePattern (consumer (advanced))

Sets the exchange pattern when the consumer creates an exchange.

Enum values:

  • InOnly

  • InOut

ExchangePattern

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

replicatedmap cache producer

The replicatedmap producer provides 6 operations:

  • put

  • get

  • delete

  • clear

  • containsKey

  • containsValue

Message Headers

The Hazelcast Replicated Map component supports 6 message header(s), which is/are listed below:

Name Description Default Type

CamelHazelcastObjectId (common)

Constant: OBJECT_ID

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

String

CamelHazelcastListenerAction (consumer)

Constant: LISTENER_ACTION

The type of event - here added and removed.

String

CamelHazelcastListenerType (consumer)

Constant: LISTENER_TYPE

The map consumer.

String

CamelHazelcastListenerTime (consumer)

Constant: LISTENER_TIME

The time of the event in millis.

Long

CamelHazelcastCacheName (consumer)

Constant: CACHE_NAME

The name of the cache - e.g. foo.

String

CamelHazelcastOperationType (producer)

Constant: OPERATION

The operation to perform.

String

Sample for put:

Java DSL:

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

Spring DSL:

<route>
    <from uri="direct:put" />
    <log message="put.."/>
    <setHeader name="hazelcast.operation.type">
        <constant>put</constant>
    </setHeader>
    <to uri="hazelcast-replicatedmap:foo" />
</route>

Sample for get:

Java DSL:

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

Spring DSL:

<route>
    <from uri="direct:get" />
    <log message="get.."/>
    <setHeader name="hazelcast.operation.type">
        <constant>get</constant>
    </setHeader>
    <to uri="hazelcast-replicatedmap:foo" />
    <to uri="seda:out" />
</route>

Sample for delete:

Java DSL:

from("direct:delete")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.DELETE))
.toF("hazelcast-%sbar", HazelcastConstants.REPLICATEDMAP_PREFIX);

Spring DSL:

<route>
    <from uri="direct:delete" />
    <log message="delete.."/>
    <setHeader name="hazelcast.operation.type">
        <constant>delete</constant>
    </setHeader>
    <to uri="hazelcast-replicatedmap:foo" />
</route>

you can call them in your test class with:

template.sendBodyAndHeader("direct:[put|get|delete|clear]", "my-foo", HazelcastConstants.OBJECT_ID, "4711");

replicatedmap cache consumer

For the multimap cache this component provides the same listeners / variables as for the map cache consumer (except the update and enviction listener). The only difference is the multimap prefix inside the URI. Here is a sample:

fromF("hazelcast-%sbar", HazelcastConstants.MULTIMAP_PREFIX)
.log("object...")
.choice()
    .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ADDED))
        .log("...added")
                .to("mock:added")
        //.when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ENVICTED))
        //        .log("...envicted")
        //        .to("mock:envicted")
        .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.REMOVED))
                .log("...removed")
                .to("mock:removed")
        .otherwise()
                .log("fail!");

Header Variables inside the response message:

Name Type Description

CamelHazelcastListenerTime

Long

time of the event in millis

CamelHazelcastListenerType

String

the map consumer sets here "cachelistener"

CamelHazelcastListenerAction

String

type of event - here added and removed (and soon envicted)

CamelHazelcastObjectId

String

the oid of the object

CamelHazelcastCacheName

String

the name of the cache - e.g. "foo"

CamelHazelcastCacheType

String

the type of the cache - here replicatedmap