URI format and options - 6.3

Talend ESB Mediation Developer Guide

EnrichVersion
6.3
EnrichProdName
Talend Data Fabric
Talend Data Services Platform
Talend ESB
Talend MDM Platform
Talend Open Studio for ESB
Talend Real-Time Big Data Platform
task
Design and Development
EnrichPlatform
Talend ESB
seda:someName[?options]

Where someName can be any string that uniquely identifies the endpoint within the current CamelContext.

You can append query options to the URI in the following format, ?option=value&option=value&...

Note: the same queue name must be used for both producer and consumer.

An exactly identical SEDA queue name must be used for both the producer endpoint and the consumer endpoint. Otherwise Camel will create a second Camel Component: SEDA endpoint, even though the someName portion of the queue is identical. For example:

from("direct:foo").to("seda:bar?concurrentConsumers=5");
from("seda:bar?concurrentConsumers=5").to("file://output");

And where URI option can be:

Table 18. 

Name

Default

Description

size

 

The maximum capacity of the SEDA queue (i.e., the number of messages it can hold). The default value in Camel 2.2 or older is 1000. From Camel 2.3 onwards, the size is unbounded by default. Notice: Mind if you use this option, then its the first endpoint being created with the queue name, that determines the size. To make sure all endpoints use same size, then configure the size option on all of them, or the first endpoint being created. From Camel 2.11 onwards, a validation is taken place to ensure if using mixed queue sizes for the same queue name, Camel would detect this and fail creating the endpoint.

concurrent-Consumers

1

Number of concurrent threads processing exchanges.

waitForTaskTo-Complete

IfReplyExpected

Option to specify whether the caller should wait for the async task to complete or not before continuing. The following three options are supported: Always, Never or IfReplyExpected. The first two values are self-explanatory. The last value, IfReplyExpected, will only wait if the message is Request Reply based. The default option is IfReplyExpected. See more information about Async messaging.

timeout

30000

Timeout in milliseconds a seda producer will at most waiting for an async task to complete. See waitForTaskToComplete and Async for more details. You can disable timeout by using 0 or a negative value.

multipleConsumers

false

Specifies whether multiple consumers are allowed. If enabled, you can use Camel Component: SEDA for Publish-Subscribe messaging. That is, you can send a message to the SEDA queue and have each consumer receive a copy of the message. When enabled, this option should be specified on every consumer endpoint.

limitConcurrent-Consumers

true

Whether to limit the concurrentConsumers to maximum 500. By default, an exception will be thrown if a SEDA endpoint is configured with a greater number. You can disable that check by turning this option off.

blockWhenFullfalse

Whether a thread that sends messages to a full SEDA queue will block until the queue's capacity is no longer exhausted. By default, an exception will be thrown stating that the queue is full. By enabling this option, the calling thread will instead block and wait until the message can be accepted.

queueSize Component only. The maximum default size (capacity of the number of messages it can hold) of the SEDA queue. This option is used if size is not in use.
pollTimeout1000Consumer only. The timeout used when polling. When a timeout occurs then the consumer can check whether its allowed to continue to run. Setting a lower value allows the consumer to react faster upon shutting down.
purgeWhenStoppingfalse

Whether to purge the task queue when stopping the consumer/route. This allows to stop faster, as any pending messages on the queue is discarded.

queuenull

Define the queue instance which will be used by seda endpoint

queueFactorynull

Define the QueueFactory which could create the queue for the seda endpoint

failIfNoConsumersfalse

Whether the producer should fail by throwing an exception, when sending to a SEDA queue with no active consumers.


See the Camel Website for the most up-to-date examples of this component in use.

Choosing BlockingQueue implementation

Available as of Camel 2.12

By default, the SEDA component always intantiates LinkedBlockingQueue, but you can use different implementation, you can reference your own BlockingQueue implementation, in this case the size option is not used

<bean id="arrayQueue" class="java.util.ArrayBlockingQueue">
<constructor-arg index="0" value="10" ><!-- size -->
<constructor-arg index="1" value="true" ><!-- fairness -->
</bean>
<!-- ... and later -->
<from>seda:array?queue=#arrayQueue</from>

Or you can reference a BlockingQueueFactory implementation, 3 implementations are provided LinkedBlockingQueueFactory, ArrayBlockingQueueFactory and PriorityBlockingQueueFactory:

<bean id="priorityQueueFactory" class="org.apache.camel.component.seda.PriorityBlockingQueueFactory">
<property name="comparator">
<bean class="org.apache.camel.demo.MyExchangeComparator" />
</property>
</bean>
<!-- ... and later -->
<from>seda:priority?queueFactory=#priorityQueueFactory&size=100</from>