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Chapter 36. AWS Simple Queue Service Component
Available as of Camel version 2.6
The sqs component supports sending and receiving messages to Amazon’s SQS service.
Prerequisites
You must have a valid Amazon Web Services developer account, and be signed up to use Amazon SQS. More information are available at Amazon SQS.
36.1. URI Format
aws-sqs://queueNameOrArn[?options]
The queue will be created if they don’t already exists.
You can append query options to the URI in the following format, ?options=value&option2=value&…
36.2. URI Options
The AWS Simple Queue Service component supports 5 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
configuration (advanced) | The AWS SQS default configuration | SqsConfiguration | |
accessKey (common) | Amazon AWS Access Key | String | |
secretKey (common) | Amazon AWS Secret Key | String | |
region (common) | Specify the queue region which could be used with queueOwnerAWSAccountId to build the service URL. | 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 AWS Simple Queue Service endpoint is configured using URI syntax:
aws-sqs:queueNameOrArn
with the following path and query parameters:
36.2.1. Path Parameters (1 parameters):
Name | Description | Default | Type |
---|---|---|---|
queueNameOrArn | Required Queue name or ARN | String |
36.2.2. Query Parameters (49 parameters):
Name | Description | Default | Type |
---|---|---|---|
amazonAWSHost (common) | The hostname of the Amazon AWS cloud. | amazonaws.com | String |
amazonSQSClient (common) | To use the AmazonSQS as client | AmazonSQS | |
headerFilterStrategy (common) | To use a custom HeaderFilterStrategy to map headers to/from Camel. | HeaderFilterStrategy | |
queueOwnerAWSAccountId (common) | Specify the queue owner aws account id when you need to connect the queue with different account owner. | String | |
region (common) | Specify the queue region which could be used with queueOwnerAWSAccountId to build the service URL. | String | |
useIAMCredentials (common) | Set whether the SQS client should expect to load credentials on an EC2 instance or to expect static credentials to be passed in. | false | boolean |
attributeNames (consumer) | A list of attribute names to receive when consuming. Multiple names can be separated by comma. | String | |
bridgeErrorHandler (consumer) | Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. 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 |
concurrentConsumers (consumer) | Allows you to use multiple threads to poll the sqs queue to increase throughput | 1 | int |
defaultVisibilityTimeout (consumer) | The default visibility timeout (in seconds) | Integer | |
deleteAfterRead (consumer) | Delete message from SQS after it has been read | true | boolean |
deleteIfFiltered (consumer) | Whether or not to send the DeleteMessage to the SQS queue if an exchange fails to get through a filter. If 'false' and exchange does not make it through a Camel filter upstream in the route, then don’t send DeleteMessage. | true | boolean |
extendMessageVisibility (consumer) | If enabled then a scheduled background task will keep extending the message visibility on SQS. This is needed if it takes a long time to process the message. If set to true defaultVisibilityTimeout must be set. See details at Amazon docs. | false | boolean |
maxMessagesPerPoll (consumer) | Gets the maximum number of messages as a limit to poll at each polling. Is default unlimited, but use 0 or negative number to disable it as unlimited. | int | |
messageAttributeNames (consumer) | A list of message attribute names to receive when consuming. Multiple names can be separated by comma. | String | |
sendEmptyMessageWhenIdle (consumer) | If the polling consumer did not poll any files, you can enable this option to send an empty message (no body) instead. | false | boolean |
visibilityTimeout (consumer) | The duration (in seconds) that the received messages are hidden from subsequent retrieve requests after being retrieved by a ReceiveMessage request to set in the com.amazonaws.services.sqs.model.SetQueueAttributesRequest. This only make sense if its different from defaultVisibilityTimeout. It changes the queue visibility timeout attribute permanently. | Integer | |
waitTimeSeconds (consumer) | Duration in seconds (0 to 20) that the ReceiveMessage action call will wait until a message is in the queue to include in the response. | Integer | |
exceptionHandler (consumer) | 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) | Sets the exchange pattern when the consumer creates an exchange. | ExchangePattern | |
pollStrategy (consumer) | A pluggable org.apache.camel.PollingConsumerPollingStrategy allowing you to provide your custom implementation to control error handling usually occurred during the poll operation before an Exchange have been created and being routed in Camel. | PollingConsumerPoll Strategy | |
delaySeconds (producer) | Delay sending messages for a number of seconds. | Integer | |
messageDeduplicationId Strategy (producer) | Only for FIFO queues. Strategy for setting the messageDeduplicationId on the message. Can be one of the following options: useExchangeId, useContentBasedDeduplication. For the useContentBasedDeduplication option, no messageDeduplicationId will be set on the message. | useExchangeId | MessageDeduplicationId Strategy |
messageGroupIdStrategy (producer) | Only for FIFO queues. Strategy for setting the messageGroupId on the message. Can be one of the following options: useConstant, useExchangeId, usePropertyValue. For the usePropertyValue option, the value of property CamelAwsMessageGroupId will be used. | MessageGroupIdStrategy | |
delayQueue (advanced) | Define if you want to apply delaySeconds option to the queue or on single messages | false | boolean |
queueUrl (advanced) | To define the queueUrl explicitly. All other parameters, which would influence the queueUrl, are ignored. This parameter is intended to be used, to connect to a mock implementation of SQS, for testing purposes. | String | |
synchronous (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean |
backoffErrorThreshold (scheduler) | The number of subsequent error polls (failed due some error) that should happen before the backoffMultipler should kick-in. | int | |
backoffIdleThreshold (scheduler) | The number of subsequent idle polls that should happen before the backoffMultipler should kick-in. | int | |
backoffMultiplier (scheduler) | To let the scheduled polling consumer backoff if there has been a number of subsequent idles/errors in a row. The multiplier is then the number of polls that will be skipped before the next actual attempt is happening again. When this option is in use then backoffIdleThreshold and/or backoffErrorThreshold must also be configured. | int | |
delay (scheduler) | Milliseconds before the next poll. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour). | 500 | long |
greedy (scheduler) | If greedy is enabled, then the ScheduledPollConsumer will run immediately again, if the previous run polled 1 or more messages. | false | boolean |
initialDelay (scheduler) | Milliseconds before the first poll starts. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour). | 1000 | long |
runLoggingLevel (scheduler) | The consumer logs a start/complete log line when it polls. This option allows you to configure the logging level for that. | TRACE | LoggingLevel |
scheduledExecutorService (scheduler) | Allows for configuring a custom/shared thread pool to use for the consumer. By default each consumer has its own single threaded thread pool. | ScheduledExecutor Service | |
scheduler (scheduler) | To use a cron scheduler from either camel-spring or camel-quartz2 component | none | ScheduledPollConsumer Scheduler |
schedulerProperties (scheduler) | To configure additional properties when using a custom scheduler or any of the Quartz2, Spring based scheduler. | Map | |
startScheduler (scheduler) | Whether the scheduler should be auto started. | true | boolean |
timeUnit (scheduler) | Time unit for initialDelay and delay options. | MILLISECONDS | TimeUnit |
useFixedDelay (scheduler) | Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details. | true | boolean |
proxyHost (proxy) | To define a proxy host when instantiating the SQS client | String | |
proxyPort (proxy) | To define a proxy port when instantiating the SQS client | Integer | |
maximumMessageSize (queue) | The maximumMessageSize (in bytes) an SQS message can contain for this queue. | Integer | |
messageRetentionPeriod (queue) | The messageRetentionPeriod (in seconds) a message will be retained by SQS for this queue. | Integer | |
policy (queue) | The policy for this queue | String | |
receiveMessageWaitTime Seconds (queue) | If you do not specify WaitTimeSeconds in the request, the queue attribute ReceiveMessageWaitTimeSeconds is used to determine how long to wait. | Integer | |
redrivePolicy (queue) | Specify the policy that send message to DeadLetter queue. See detail at Amazon docs. | String | |
accessKey (security) | Amazon AWS Access Key | String | |
secretKey (security) | Amazon AWS Secret Key | String |
36.3. Spring Boot Auto-Configuration
The component supports 31 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
camel.component.aws-sqs.access-key | Amazon AWS Access Key | String | |
camel.component.aws-sqs.configuration.access-key | Amazon AWS Access Key | String | |
camel.component.aws-sqs.configuration.amazon-a-w-s-host | The hostname of the Amazon AWS cloud. | amazonaws.com | String |
camel.component.aws-sqs.configuration.amazon-s-q-s-client | To use the AmazonSQS as client | AmazonSQS | |
camel.component.aws-sqs.configuration.attribute-names | A list of attribute names to receive when consuming. Multiple names can be separated by comma. | String | |
camel.component.aws-sqs.configuration.concurrent-consumers | Allows you to use multiple threads to poll the sqs queue to increase throughput | 1 | Integer |
camel.component.aws-sqs.configuration.default-visibility-timeout | The default visibility timeout (in seconds) | Integer | |
camel.component.aws-sqs.configuration.delay-queue | Define if you want to apply delaySeconds option to the queue or on single messages | false | Boolean |
camel.component.aws-sqs.configuration.delay-seconds | Delay sending messages for a number of seconds. | Integer | |
camel.component.aws-sqs.configuration.delete-after-read | Delete message from SQS after it has been read | true | Boolean |
camel.component.aws-sqs.configuration.delete-if-filtered | Whether or not to send the DeleteMessage to the SQS queue if an exchange fails to get through a filter. If 'false' and exchange does not make it through a Camel filter upstream in the route, then don’t send DeleteMessage. | true | Boolean |
camel.component.aws-sqs.configuration.extend-message-visibility | If enabled then a scheduled background task will keep extending the message visibility on SQS. This is needed if it takes a long time to process the message. If set to true defaultVisibilityTimeout must be set. See details at Amazon docs. | false | Boolean |
camel.component.aws-sqs.configuration.maximum-message-size | The maximumMessageSize (in bytes) an SQS message can contain for this queue. | Integer | |
camel.component.aws-sqs.configuration.message-attribute-names | A list of message attribute names to receive when consuming. Multiple names can be separated by comma. | String | |
camel.component.aws-sqs.configuration.message-retention-period | The messageRetentionPeriod (in seconds) a message will be retained by SQS for this queue. | Integer | |
camel.component.aws-sqs.configuration.policy | The policy for this queue | String | |
camel.component.aws-sqs.configuration.proxy-host | To define a proxy host when instantiating the SQS client | String | |
camel.component.aws-sqs.configuration.proxy-port | To define a proxy port when instantiating the SQS client | Integer | |
camel.component.aws-sqs.configuration.queue-name | Name of queue. The queue will be created if they don’t already exists. | String | |
camel.component.aws-sqs.configuration.queue-owner-a-w-s-account-id | Specify the queue owner aws account id when you need to connect the queue with different account owner. | String | |
camel.component.aws-sqs.configuration.queue-url | To define the queueUrl explicitly. All other parameters, which would influence the queueUrl, are ignored. This parameter is intended to be used, to connect to a mock implementation of SQS, for testing purposes. | String | |
camel.component.aws-sqs.configuration.receive-message-wait-time-seconds | If you do not specify WaitTimeSeconds in the request, the queue attribute ReceiveMessageWaitTimeSeconds is used to determine how long to wait. | Integer | |
camel.component.aws-sqs.configuration.redrive-policy | Specify the policy that send message to DeadLetter queue. See detail at Amazon docs. | String | |
camel.component.aws-sqs.configuration.region | Specify the queue region which could be used with queueOwnerAWSAccountId to build the service URL. | String | |
camel.component.aws-sqs.configuration.secret-key | Amazon AWS Secret Key | String | |
camel.component.aws-sqs.configuration.visibility-timeout | The duration (in seconds) that the received messages are hidden from subsequent retrieve requests after being retrieved by a ReceiveMessage request to set in the com.amazonaws.services.sqs.model.SetQueueAttributesRequest. This only make sense if its different from defaultVisibilityTimeout. It changes the queue visibility timeout attribute permanently. | Integer | |
camel.component.aws-sqs.configuration.wait-time-seconds | Duration in seconds (0 to 20) that the ReceiveMessage action call will wait until a message is in the queue to include in the response. | Integer | |
camel.component.aws-sqs.enabled | Enable aws-sqs component | true | Boolean |
camel.component.aws-sqs.region | Specify the queue region which could be used with queueOwnerAWSAccountId to build the service URL. | String | |
camel.component.aws-sqs.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 |
camel.component.aws-sqs.secret-key | Amazon AWS Secret Key | String |
Required SQS component options
You have to provide the amazonSQSClient in the Registry or your accessKey and secretKey to access the Amazon’s SQS.
36.4. Batch Consumer
This component implements the Batch Consumer.
This allows you for instance to know how many messages exists in this batch and for instance let the Aggregator aggregate this number of messages.
36.5. Usage
36.5.1. Message headers set by the SQS producer
Header | Type | Description |
---|---|---|
|
| The MD5 checksum of the Amazon SQS message. |
|
| The Amazon SQS message ID. |
|
| Since Camel 2.11, the delay seconds that the Amazon SQS message can be see by others. |
36.5.2. Message headers set by the SQS consumer
Header | Type | Description |
---|---|---|
|
| The MD5 checksum of the Amazon SQS message. |
|
| The Amazon SQS message ID. |
|
| The Amazon SQS message receipt handle. |
|
| The Amazon SQS message attributes. |
36.5.3. Advanced AmazonSQS configuration
If your Camel Application is running behind a firewall or if you need to have more control over the AmazonSQS instance configuration, you can create your own instance:
AWSCredentials awsCredentials = new BasicAWSCredentials("myAccessKey", "mySecretKey"); ClientConfiguration clientConfiguration = new ClientConfiguration(); clientConfiguration.setProxyHost("http://myProxyHost"); clientConfiguration.setProxyPort(8080); AmazonSQS client = new AmazonSQSClient(awsCredentials, clientConfiguration); registry.bind("client", client);
and refer to it in your Camel aws-sqs component configuration:
from("aws-sqs://MyQueue?amazonSQSClient=#client&delay=5000&maxMessagesPerPoll=5") .to("mock:result");
36.5.4. Creating or updating an SQS Queue
In the SQS Component, when an endpoint is started, a check is executed to obtain information about the existence of the queue or not. You’re able to customize the creation through the QueueAttributeName mapping with the SQSConfiguration option.
from("aws-sqs://MyQueue?amazonSQSClient=#client&delay=5000&maxMessagesPerPoll=5") .to("mock:result");
In this example if the MyQueue queue is not already created on AWS, it will be created with default parameters from the SQS configuration. If it’s already up on AWS, the SQS configuration options will be used to override the existent AWS configuration.
36.5.5. DelayQueue VS Delay for Single message
From 2.23.0 the component has a new option: delayQueue. When the option is set to true, the SQS Queue will be a DelayQueue with the DelaySeconds option as delay. For more information about DelayQueue you can read the AWS SQS documentation. One important information to take into account is the following:
- For standard queues, the per-queue delay setting is not retroactive—changing the setting doesn’t affect the delay of messages already in the queue.
- For FIFO queues, the per-queue delay setting is retroactive—changing the setting affects the delay of messages already in the queue.
as stated in the official documentation. If you want to specify a delay on single messages, you can ignore the delayQueue option, while you can set this option to true, if you need to add a fixed delay to all messages enqueued.
36.5.6. Using AWS IAM credentials with the SQS component
To use AWS IAM credentials, you must first confirm that the EC2 instance on which you are launching the Camel application has an IAM role associated with it and that the appropriate policies are attached.
This feature should only be set to true
on remote instances. Additionally, you must also use static credentials locally as IAM is an AWS specific component.
To implement this feature set useIAMCredentials
to true
.
To toggle this feature on and off based on local and remote environments, you could consider enabling this query parameter with system environment variables. For example, your code could set the useIAMCredentials
query parameter to true
if a system environment variable named isRemote
is set to true
.
Although this feature does not eliminate the need for static credentials completely, using IAM credentials on AWS environments does remove the need to refresh on remote environments and is more secure as IAM credentials are refreshed automatically every six hours and are also updated when EC2 security policies are updated.
This is the AWS recommended way to manage credentials and therefore should be used as often as possible.
36.6. Dependencies
Maven users will need to add the following dependency to their pom.xml.
pom.xml
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-aws</artifactId> <version>${camel-version}</version> </dependency>
where ${camel-version
} must be replaced by the actual version of Camel (2.6 or higher).
36.7. JMS-style Selectors
SQS does not allow selectors, but you can effectively achieve this by using the Camel Filter EIP and setting an appropriate visibilityTimeout
. When SQS dispatches a message, it will wait up to the visibility timeout before it will try to dispatch the message to a different consumer unless a DeleteMessage is received. By default, Camel will always send the DeleteMessage at the end of the route, unless the route ended in failure. To achieve appropriate filtering and not send the DeleteMessage even on successful completion of the route, use a Filter:
from("aws-sqs://MyQueue?amazonSQSClient=#client&defaultVisibilityTimeout=5000&deleteIfFiltered=false") .filter("${header.login} == true") .to("mock:result");
In the above code, if an exchange doesn’t have an appropriate header, it will not make it through the filter AND also not be deleted from the SQS queue. After 5000 miliseconds, the message will become visible to other consumers.
36.8. Delete Single Message
Use deleteMessage operation to delete a single message. You’ll need to set a receipt handle header for the message you want to delete.
from("direct:start") .setHeader(SqsConstants.SQS_OPERATION, constant("deleteMessage")) .setHeader(SqsConstants.RECEIPT_HANDLE, constant("123456")) .to("aws-sqs://camel-1?accessKey=RAW(xxx)&secretKey=RAW(xxx)®ion=EU_WEST_1");
As result you’ll get an exchange containing a DeleteMessageResult
instance, that you can use to check if the message was deleted or not.
36.9. See Also
- Configuring Camel
- Component
- Endpoint
- Getting Started
- AWS Component