AWS SDK Version 2 for .NET
API Reference

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.NET Framework 3.5
 
Interface for accessing SQS Welcome to the Amazon Simple Queue Service API Reference. This section describes who should read this guide, how the guide is organized, and other resources related to the Amazon Simple Queue Service (Amazon SQS).

Amazon SQS offers reliable and scalable hosted queues for storing messages as they travel between computers. By using Amazon SQS, you can move data between distributed components of your applications that perform different tasks without losing messages or requiring each component to be always available.

Helpful Links:

We also provide SDKs that enable you to access Amazon SQS from your preferred programming language. The SDKs contain functionality that automatically takes care of tasks such as:

For a list of available SDKs, go to Tools for Amazon Web Services.

Inheritance Hierarchy

Amazon.SQS.IAmazonSQS

Namespace: Amazon.SQS
Assembly: AWSSDK.dll
Version: (assembly version)

Syntax

C#
public interface IAmazonSQS
         IDisposable

The IAmazonSQS type exposes the following members

Methods

NameDescription
Public Method AddPermission(string, string, List<String>, List<String>) Adds a permission to a queue for a specific principal. This allows for sharing access to the queue.

When you create a queue, you have full control access rights for the queue. Only you (as owner of the queue) can grant or deny permissions to the queue. For more information about these permissions, see Shared Queues in the Amazon SQS Developer Guide.

AddPermission writes an Amazon SQS-generated policy. If you want to write your own policy, use SetQueueAttributes to upload your policy. For more information about writing your own policy, see Using The Access Policy Language in the Amazon SQS Developer Guide.

Some API actions take lists of parameters. These lists are specified using the param.n notation. Values of n are integers starting from 1. For example, a parameter list with two elements looks like this:

&Attribute.1=this

&Attribute.2=that

Public Method AddPermission(AddPermissionRequest) Adds a permission to a queue for a specific principal. This allows for sharing access to the queue.

When you create a queue, you have full control access rights for the queue. Only you (as owner of the queue) can grant or deny permissions to the queue. For more information about these permissions, see Shared Queues in the Amazon SQS Developer Guide.

AddPermission writes an Amazon SQS-generated policy. If you want to write your own policy, use SetQueueAttributes to upload your policy. For more information about writing your own policy, see Using The Access Policy Language in the Amazon SQS Developer Guide.

Some API actions take lists of parameters. These lists are specified using the param.n notation. Values of n are integers starting from 1. For example, a parameter list with two elements looks like this:

&Attribute.1=this

&Attribute.2=that

Public Method AuthorizeS3ToSendMessage(string, string) This is a utility method which updates the policy of a queue to allow the S3 bucket to publish events to it.
Public Method BeginAddPermission(AddPermissionRequest, AsyncCallback, object) Initiates the asynchronous execution of the AddPermission operation.
Public Method BeginChangeMessageVisibility(ChangeMessageVisibilityRequest, AsyncCallback, object) Initiates the asynchronous execution of the ChangeMessageVisibility operation.
Public Method BeginChangeMessageVisibilityBatch(ChangeMessageVisibilityBatchRequest, AsyncCallback, object) Initiates the asynchronous execution of the ChangeMessageVisibilityBatch operation.
Public Method BeginCreateQueue(CreateQueueRequest, AsyncCallback, object) Initiates the asynchronous execution of the CreateQueue operation.
Public Method BeginDeleteMessage(DeleteMessageRequest, AsyncCallback, object) Initiates the asynchronous execution of the DeleteMessage operation.
Public Method BeginDeleteMessageBatch(DeleteMessageBatchRequest, AsyncCallback, object) Initiates the asynchronous execution of the DeleteMessageBatch operation.
Public Method BeginDeleteQueue(DeleteQueueRequest, AsyncCallback, object) Initiates the asynchronous execution of the DeleteQueue operation.
Public Method BeginGetQueueAttributes(GetQueueAttributesRequest, AsyncCallback, object) Initiates the asynchronous execution of the GetQueueAttributes operation.
Public Method BeginGetQueueUrl(GetQueueUrlRequest, AsyncCallback, object) Initiates the asynchronous execution of the GetQueueUrl operation.
Public Method BeginListDeadLetterSourceQueues(ListDeadLetterSourceQueuesRequest, AsyncCallback, object) Initiates the asynchronous execution of the ListDeadLetterSourceQueues operation.
Public Method BeginListQueues(ListQueuesRequest, AsyncCallback, object) Initiates the asynchronous execution of the ListQueues operation.
Public Method BeginPurgeQueue(PurgeQueueRequest, AsyncCallback, object) Initiates the asynchronous execution of the PurgeQueue operation.
Public Method BeginReceiveMessage(ReceiveMessageRequest, AsyncCallback, object) Initiates the asynchronous execution of the ReceiveMessage operation.
Public Method BeginRemovePermission(RemovePermissionRequest, AsyncCallback, object) Initiates the asynchronous execution of the RemovePermission operation.
Public Method BeginSendMessage(SendMessageRequest, AsyncCallback, object) Initiates the asynchronous execution of the SendMessage operation.
Public Method BeginSendMessageBatch(SendMessageBatchRequest, AsyncCallback, object) Initiates the asynchronous execution of the SendMessageBatch operation.
Public Method BeginSetQueueAttributes(SetQueueAttributesRequest, AsyncCallback, object) Initiates the asynchronous execution of the SetQueueAttributes operation.
Public Method ChangeMessageVisibility(string, string, int) Changes the visibility timeout of a specified message in a queue to a new value. The maximum allowed timeout value you can set the value to is 12 hours. This means you can't extend the timeout of a message in an existing queue to more than a total visibility timeout of 12 hours. (For more information visibility timeout, see Visibility Timeout in the Amazon SQS Developer Guide.)

For example, let's say you have a message and its default message visibility timeout is 30 minutes. You could call ChangeMessageVisiblity with a value of two hours and the effective timeout would be two hours and 30 minutes. When that time comes near you could again extend the time out by calling ChangeMessageVisiblity, but this time the maximum allowed timeout would be 9 hours and 30 minutes.

There is a 120,000 limit for the number of inflight messages per queue. Messages are inflight after they have been received from the queue by a consuming component, but have not yet been deleted from the queue. If you reach the 120,000 limit, you will receive an OverLimit error message from Amazon SQS. To help avoid reaching the limit, you should delete the messages from the queue after they have been processed. You can also increase the number of queues you use to process the messages.

If you attempt to set the VisibilityTimeout to an amount more than the maximum time left, Amazon SQS returns an error. It will not automatically recalculate and increase the timeout to the maximum time remaining.Unlike with a queue, when you change the visibility timeout for a specific message, that timeout value is applied immediately but is not saved in memory for that message. If you don't delete a message after it is received, the visibility timeout for the message the next time it is received reverts to the original timeout value, not the value you set with the ChangeMessageVisibility action.
Public Method ChangeMessageVisibility(ChangeMessageVisibilityRequest) Changes the visibility timeout of a specified message in a queue to a new value. The maximum allowed timeout value you can set the value to is 12 hours. This means you can't extend the timeout of a message in an existing queue to more than a total visibility timeout of 12 hours. (For more information visibility timeout, see Visibility Timeout in the Amazon SQS Developer Guide.)

For example, let's say you have a message and its default message visibility timeout is 30 minutes. You could call ChangeMessageVisiblity with a value of two hours and the effective timeout would be two hours and 30 minutes. When that time comes near you could again extend the time out by calling ChangeMessageVisiblity, but this time the maximum allowed timeout would be 9 hours and 30 minutes.

There is a 120,000 limit for the number of inflight messages per queue. Messages are inflight after they have been received from the queue by a consuming component, but have not yet been deleted from the queue. If you reach the 120,000 limit, you will receive an OverLimit error message from Amazon SQS. To help avoid reaching the limit, you should delete the messages from the queue after they have been processed. You can also increase the number of queues you use to process the messages.

If you attempt to set the VisibilityTimeout to an amount more than the maximum time left, Amazon SQS returns an error. It will not automatically recalculate and increase the timeout to the maximum time remaining.Unlike with a queue, when you change the visibility timeout for a specific message, that timeout value is applied immediately but is not saved in memory for that message. If you don't delete a message after it is received, the visibility timeout for the message the next time it is received reverts to the original timeout value, not the value you set with the ChangeMessageVisibility action.
Public Method ChangeMessageVisibilityBatch(string, List<ChangeMessageVisibilityBatchRequestEntry>) Changes the visibility timeout of multiple messages. This is a batch version of ChangeMessageVisibility. The result of the action on each message is reported individually in the response. You can send up to 10 ChangeMessageVisibility requests with each ChangeMessageVisibilityBatch action. Because the batch request can result in a combination of successful and unsuccessful actions, you should check for batch errors even when the call returns an HTTP status code of 200.Some API actions take lists of parameters. These lists are specified using the param.n notation. Values of n are integers starting from 1. For example, a parameter list with two elements looks like this:

&Attribute.1=this

&Attribute.2=that

Public Method ChangeMessageVisibilityBatch(ChangeMessageVisibilityBatchRequest) Changes the visibility timeout of multiple messages. This is a batch version of ChangeMessageVisibility. The result of the action on each message is reported individually in the response. You can send up to 10 ChangeMessageVisibility requests with each ChangeMessageVisibilityBatch action. Because the batch request can result in a combination of successful and unsuccessful actions, you should check for batch errors even when the call returns an HTTP status code of 200.Some API actions take lists of parameters. These lists are specified using the param.n notation. Values of n are integers starting from 1. For example, a parameter list with two elements looks like this:

&Attribute.1=this

&Attribute.2=that

Public Method CreateQueue(string) Creates a new queue, or returns the URL of an existing one. When you request CreateQueue, you provide a name for the queue. To successfully create a new queue, you must provide a name that is unique within the scope of your own queues.

If you delete a queue, you must wait at least 60 seconds before creating a queue with the same name.

You may pass one or more attributes in the request. If you do not provide a value for any attribute, the queue will have the default value for that attribute. Permitted attributes are the same that can be set using SetQueueAttributes.

Use GetQueueUrl to get a queue's URL. GetQueueUrl requires only the QueueName parameter.

If you provide the name of an existing queue, along with the exact names and values of all the queue's attributes, CreateQueue returns the queue URL for the existing queue. If the queue name, attribute names, or attribute values do not match an existing queue, CreateQueue returns an error.

Some API actions take lists of parameters. These lists are specified using the param.n notation. Values of n are integers starting from 1. For example, a parameter list with two elements looks like this:

&Attribute.1=this

&Attribute.2=that

Public Method CreateQueue(CreateQueueRequest) Creates a new queue, or returns the URL of an existing one. When you request CreateQueue, you provide a name for the queue. To successfully create a new queue, you must provide a name that is unique within the scope of your own queues.

If you delete a queue, you must wait at least 60 seconds before creating a queue with the same name.

You may pass one or more attributes in the request. If you do not provide a value for any attribute, the queue will have the default value for that attribute. Permitted attributes are the same that can be set using SetQueueAttributes.

Use GetQueueUrl to get a queue's URL. GetQueueUrl requires only the QueueName parameter.

If you provide the name of an existing queue, along with the exact names and values of all the queue's attributes, CreateQueue returns the queue URL for the existing queue. If the queue name, attribute names, or attribute values do not match an existing queue, CreateQueue returns an error.

Some API actions take lists of parameters. These lists are specified using the param.n notation. Values of n are integers starting from 1. For example, a parameter list with two elements looks like this:

&Attribute.1=this

&Attribute.2=that

Public Method DeleteMessage(string, string) Deletes the specified message from the specified queue. You specify the message by using the message's receipt handle and not the message ID you received when you sent the message. Even if the message is locked by another reader due to the visibility timeout setting, it is still deleted from the queue. If you leave a message in the queue for longer than the queue's configured retention period, Amazon SQS automatically deletes it.

The receipt handle is associated with a specific instance of receiving the message. If you receive a message more than once, the receipt handle you get each time you receive the message is different. When you request DeleteMessage, if you don't provide the most recently received receipt handle for the message, the request will still succeed, but the message might not be deleted.

It is possible you will receive a message even after you have deleted it. This might happen on rare occasions if one of the servers storing a copy of the message is unavailable when you request to delete the message. The copy remains on the server and might be returned to you again on a subsequent receive request. You should create your system to be idempotent so that receiving a particular message more than once is not a problem.

Public Method DeleteMessage(DeleteMessageRequest) Deletes the specified message from the specified queue. You specify the message by using the message's receipt handle and not the message ID you received when you sent the message. Even if the message is locked by another reader due to the visibility timeout setting, it is still deleted from the queue. If you leave a message in the queue for longer than the queue's configured retention period, Amazon SQS automatically deletes it.

The receipt handle is associated with a specific instance of receiving the message. If you receive a message more than once, the receipt handle you get each time you receive the message is different. When you request DeleteMessage, if you don't provide the most recently received receipt handle for the message, the request will still succeed, but the message might not be deleted.

It is possible you will receive a message even after you have deleted it. This might happen on rare occasions if one of the servers storing a copy of the message is unavailable when you request to delete the message. The copy remains on the server and might be returned to you again on a subsequent receive request. You should create your system to be idempotent so that receiving a particular message more than once is not a problem.

Public Method DeleteMessageBatch(string, List<DeleteMessageBatchRequestEntry>) Deletes up to ten messages from the specified queue. This is a batch version of DeleteMessage. The result of the delete action on each message is reported individually in the response.

Because the batch request can result in a combination of successful and unsuccessful actions, you should check for batch errors even when the call returns an HTTP status code of 200.

Some API actions take lists of parameters. These lists are specified using the param.n notation. Values of n are integers starting from 1. For example, a parameter list with two elements looks like this:

&Attribute.1=this

&Attribute.2=that

Public Method DeleteMessageBatch(DeleteMessageBatchRequest) Deletes up to ten messages from the specified queue. This is a batch version of DeleteMessage. The result of the delete action on each message is reported individually in the response.

Because the batch request can result in a combination of successful and unsuccessful actions, you should check for batch errors even when the call returns an HTTP status code of 200.

Some API actions take lists of parameters. These lists are specified using the param.n notation. Values of n are integers starting from 1. For example, a parameter list with two elements looks like this:

&Attribute.1=this

&Attribute.2=that

Public Method DeleteQueue(string) Deletes the queue specified by the queue URL, regardless of whether the queue is empty. If the specified queue does not exist, Amazon SQS returns a successful response.

Use DeleteQueue with care; once you delete your queue, any messages in the queue are no longer available.

When you delete a queue, the deletion process takes up to 60 seconds. Requests you send involving that queue during the 60 seconds might succeed. For example, a SendMessage request might succeed, but after the 60 seconds, the queue and that message you sent no longer exist. Also, when you delete a queue, you must wait at least 60 seconds before creating a queue with the same name.

We reserve the right to delete queues that have had no activity for more than 30 days. For more information, see How Amazon SQS Queues Work in the Amazon SQS Developer Guide.

Public Method DeleteQueue(DeleteQueueRequest) Deletes the queue specified by the queue URL, regardless of whether the queue is empty. If the specified queue does not exist, Amazon SQS returns a successful response.

Use DeleteQueue with care; once you delete your queue, any messages in the queue are no longer available.

When you delete a queue, the deletion process takes up to 60 seconds. Requests you send involving that queue during the 60 seconds might succeed. For example, a SendMessage request might succeed, but after the 60 seconds, the queue and that message you sent no longer exist. Also, when you delete a queue, you must wait at least 60 seconds before creating a queue with the same name.

We reserve the right to delete queues that have had no activity for more than 30 days. For more information, see How Amazon SQS Queues Work in the Amazon SQS Developer Guide.

Public Method EndAddPermission(IAsyncResult) Finishes the asynchronous execution of the AddPermission operation.
Public Method EndChangeMessageVisibility(IAsyncResult) Finishes the asynchronous execution of the ChangeMessageVisibility operation.
Public Method EndChangeMessageVisibilityBatch(IAsyncResult) Finishes the asynchronous execution of the ChangeMessageVisibilityBatch operation.
Public Method EndCreateQueue(IAsyncResult) Finishes the asynchronous execution of the CreateQueue operation.
Public Method EndDeleteMessage(IAsyncResult) Finishes the asynchronous execution of the DeleteMessage operation.
Public Method EndDeleteMessageBatch(IAsyncResult) Finishes the asynchronous execution of the DeleteMessageBatch operation.
Public Method EndDeleteQueue(IAsyncResult) Finishes the asynchronous execution of the DeleteQueue operation.
Public Method EndGetQueueAttributes(IAsyncResult) Finishes the asynchronous execution of the GetQueueAttributes operation.
Public Method EndGetQueueUrl(IAsyncResult) Finishes the asynchronous execution of the GetQueueUrl operation.
Public Method EndListDeadLetterSourceQueues(IAsyncResult) Finishes the asynchronous execution of the ListDeadLetterSourceQueues operation.
Public Method EndListQueues(IAsyncResult) Finishes the asynchronous execution of the ListQueues operation.
Public Method EndPurgeQueue(IAsyncResult) Finishes the asynchronous execution of the PurgeQueue operation.
Public Method EndReceiveMessage(IAsyncResult) Finishes the asynchronous execution of the ReceiveMessage operation.
Public Method EndRemovePermission(IAsyncResult) Finishes the asynchronous execution of the RemovePermission operation.
Public Method EndSendMessage(IAsyncResult) Finishes the asynchronous execution of the SendMessage operation.
Public Method EndSendMessageBatch(IAsyncResult) Finishes the asynchronous execution of the SendMessageBatch operation.
Public Method EndSetQueueAttributes(IAsyncResult) Finishes the asynchronous execution of the SetQueueAttributes operation.
Public Method GetQueueAttributes(string, List<String>) Gets attributes for the specified queue. The following attributes are supported:
  • All - returns all values.
  • ApproximateNumberOfMessages - returns the approximate number of visible messages in a queue. For more information, see Resources Required to Process Messages in the Amazon SQS Developer Guide.
  • ApproximateNumberOfMessagesNotVisible - returns the approximate number of messages that are not timed-out and not deleted. For more information, see Resources Required to Process Messages in the Amazon SQS Developer Guide.
  • VisibilityTimeout - returns the visibility timeout for the queue. For more information about visibility timeout, see Visibility Timeout in the Amazon SQS Developer Guide.
  • CreatedTimestamp - returns the time when the queue was created (epoch time in seconds).
  • LastModifiedTimestamp - returns the time when the queue was last changed (epoch time in seconds).
  • Policy - returns the queue's policy.
  • MaximumMessageSize - returns the limit of how many bytes a message can contain before Amazon SQS rejects it.
  • MessageRetentionPeriod - returns the number of seconds Amazon SQS retains a message.
  • QueueArn - returns the queue's Amazon resource name (ARN).
  • ApproximateNumberOfMessagesDelayed - returns the approximate number of messages that are pending to be added to the queue.
  • DelaySeconds - returns the default delay on the queue in seconds.
  • ReceiveMessageWaitTimeSeconds - returns the time for which a ReceiveMessage call will wait for a message to arrive.
  • RedrivePolicy - returns the parameters for dead letter queue functionality of the source queue. For more information about RedrivePolicy and dead letter queues, see Using Amazon SQS Dead Letter Queues in the Amazon SQS Developer Guide.
Going forward, new attributes might be added. If you are writing code that calls this action, we recommend that you structure your code so that it can handle new attributes gracefully.Some API actions take lists of parameters. These lists are specified using the param.n notation. Values of n are integers starting from 1. For example, a parameter list with two elements looks like this:

&Attribute.1=this

&Attribute.2=that

Public Method GetQueueAttributes(GetQueueAttributesRequest) Gets attributes for the specified queue. The following attributes are supported:
  • All - returns all values.
  • ApproximateNumberOfMessages - returns the approximate number of visible messages in a queue. For more information, see Resources Required to Process Messages in the Amazon SQS Developer Guide.
  • ApproximateNumberOfMessagesNotVisible - returns the approximate number of messages that are not timed-out and not deleted. For more information, see Resources Required to Process Messages in the Amazon SQS Developer Guide.
  • VisibilityTimeout - returns the visibility timeout for the queue. For more information about visibility timeout, see Visibility Timeout in the Amazon SQS Developer Guide.
  • CreatedTimestamp - returns the time when the queue was created (epoch time in seconds).
  • LastModifiedTimestamp - returns the time when the queue was last changed (epoch time in seconds).
  • Policy - returns the queue's policy.
  • MaximumMessageSize - returns the limit of how many bytes a message can contain before Amazon SQS rejects it.
  • MessageRetentionPeriod - returns the number of seconds Amazon SQS retains a message.
  • QueueArn - returns the queue's Amazon resource name (ARN).
  • ApproximateNumberOfMessagesDelayed - returns the approximate number of messages that are pending to be added to the queue.
  • DelaySeconds - returns the default delay on the queue in seconds.
  • ReceiveMessageWaitTimeSeconds - returns the time for which a ReceiveMessage call will wait for a message to arrive.
  • RedrivePolicy - returns the parameters for dead letter queue functionality of the source queue. For more information about RedrivePolicy and dead letter queues, see Using Amazon SQS Dead Letter Queues in the Amazon SQS Developer Guide.
Going forward, new attributes might be added. If you are writing code that calls this action, we recommend that you structure your code so that it can handle new attributes gracefully.Some API actions take lists of parameters. These lists are specified using the param.n notation. Values of n are integers starting from 1. For example, a parameter list with two elements looks like this:

&Attribute.1=this

&Attribute.2=that

Public Method GetQueueUrl(string) Returns the URL of an existing queue. This action provides a simple way to retrieve the URL of an Amazon SQS queue.

To access a queue that belongs to another AWS account, use the QueueOwnerAWSAccountId parameter to specify the account ID of the queue's owner. The queue's owner must grant you permission to access the queue. For more information about shared queue access, see AddPermission or go to Shared Queues in the Amazon SQS Developer Guide.

Public Method GetQueueUrl(GetQueueUrlRequest) Returns the URL of an existing queue. This action provides a simple way to retrieve the URL of an Amazon SQS queue.

To access a queue that belongs to another AWS account, use the QueueOwnerAWSAccountId parameter to specify the account ID of the queue's owner. The queue's owner must grant you permission to access the queue. For more information about shared queue access, see AddPermission or go to Shared Queues in the Amazon SQS Developer Guide.

Public Method ListDeadLetterSourceQueues(ListDeadLetterSourceQueuesRequest) Returns a list of your queues that have the RedrivePolicy queue attribute configured with a dead letter queue.

For more information about using dead letter queues, see Using Amazon SQS Dead Letter Queues.

Public Method ListQueues(string) Returns a list of your queues. The maximum number of queues that can be returned is 1000. If you specify a value for the optional QueueNamePrefix parameter, only queues with a name beginning with the specified value are returned.
Public Method ListQueues(ListQueuesRequest) Returns a list of your queues. The maximum number of queues that can be returned is 1000. If you specify a value for the optional QueueNamePrefix parameter, only queues with a name beginning with the specified value are returned.
Public Method PurgeQueue(string) Deletes the messages in a queue specified by the queue URL. When you use the PurgeQueue API, the deleted messages in the queue cannot be retrieved.

When you purge a queue, the message deletion process takes up to 60 seconds. All messages sent to the queue before calling PurgeQueue will be deleted; messages sent to the queue while it is being purged may be deleted. While the queue is being purged, messages sent to the queue before PurgeQueue was called may be received, but will be deleted within the next minute.

Public Method PurgeQueue(PurgeQueueRequest) Deletes the messages in a queue specified by the queue URL. When you use the PurgeQueue API, the deleted messages in the queue cannot be retrieved.

When you purge a queue, the message deletion process takes up to 60 seconds. All messages sent to the queue before calling PurgeQueue will be deleted; messages sent to the queue while it is being purged may be deleted. While the queue is being purged, messages sent to the queue before PurgeQueue was called may be received, but will be deleted within the next minute.

Public Method ReceiveMessage(string) Retrieves one or more messages, with a maximum limit of 10 messages, from the specified queue. Long poll support is enabled by using the WaitTimeSeconds parameter. For more information, see Amazon SQS Long Poll in the Amazon SQS Developer Guide.

Short poll is the default behavior where a weighted random set of machines is sampled on a ReceiveMessage call. This means only the messages on the sampled machines are returned. If the number of messages in the queue is small (less than 1000), it is likely you will get fewer messages than you requested per ReceiveMessage call. If the number of messages in the queue is extremely small, you might not receive any messages in a particular ReceiveMessage response; in which case you should repeat the request.

For each message returned, the response includes the following:

  • Message body

  • MD5 digest of the message body. For information about MD5, go to http://www.faqs.org/rfcs/rfc1321.html.

  • Message ID you received when you sent the message to the queue.

  • Receipt handle.

  • Message attributes.

  • MD5 digest of the message attributes.

The receipt handle is the identifier you must provide when deleting the message. For more information, see Queue and Message Identifiers in the Amazon SQS Developer Guide.

You can provide the VisibilityTimeout parameter in your request, which will be applied to the messages that Amazon SQS returns in the response. If you do not include the parameter, the overall visibility timeout for the queue is used for the returned messages. For more information, see Visibility Timeout in the Amazon SQS Developer Guide.

Going forward, new attributes might be added. If you are writing code that calls this action, we recommend that you structure your code so that it can handle new attributes gracefully.

Public Method ReceiveMessage(ReceiveMessageRequest) Retrieves one or more messages, with a maximum limit of 10 messages, from the specified queue. Long poll support is enabled by using the WaitTimeSeconds parameter. For more information, see Amazon SQS Long Poll in the Amazon SQS Developer Guide.

Short poll is the default behavior where a weighted random set of machines is sampled on a ReceiveMessage call. This means only the messages on the sampled machines are returned. If the number of messages in the queue is small (less than 1000), it is likely you will get fewer messages than you requested per ReceiveMessage call. If the number of messages in the queue is extremely small, you might not receive any messages in a particular ReceiveMessage response; in which case you should repeat the request.

For each message returned, the response includes the following:

  • Message body

  • MD5 digest of the message body. For information about MD5, go to http://www.faqs.org/rfcs/rfc1321.html.

  • Message ID you received when you sent the message to the queue.

  • Receipt handle.

  • Message attributes.

  • MD5 digest of the message attributes.

The receipt handle is the identifier you must provide when deleting the message. For more information, see Queue and Message Identifiers in the Amazon SQS Developer Guide.

You can provide the VisibilityTimeout parameter in your request, which will be applied to the messages that Amazon SQS returns in the response. If you do not include the parameter, the overall visibility timeout for the queue is used for the returned messages. For more information, see Visibility Timeout in the Amazon SQS Developer Guide.

Going forward, new attributes might be added. If you are writing code that calls this action, we recommend that you structure your code so that it can handle new attributes gracefully.

Public Method RemovePermission(string, string) Revokes any permissions in the queue policy that matches the specified Label parameter. Only the owner of the queue can remove permissions.
Public Method RemovePermission(RemovePermissionRequest) Revokes any permissions in the queue policy that matches the specified Label parameter. Only the owner of the queue can remove permissions.
Public Method SendMessage(string, string) Delivers a message to the specified queue. With Amazon SQS, you now have the ability to send large payload messages that are up to 256KB (262,144 bytes) in size. To send large payloads, you must use an AWS SDK that supports SigV4 signing. To verify whether SigV4 is supported for an AWS SDK, check the SDK release notes.

The following list shows the characters (in Unicode) allowed in your message, according to the W3C XML specification. For more information, go to http://www.w3.org/TR/REC-xml/#charsets If you send any characters not included in the list, your request will be rejected.

#x9 | #xA | #xD | [#x20 to #xD7FF] | [#xE000 to #xFFFD] | [#x10000 to #x10FFFF]

Public Method SendMessage(SendMessageRequest) Delivers a message to the specified queue. With Amazon SQS, you now have the ability to send large payload messages that are up to 256KB (262,144 bytes) in size. To send large payloads, you must use an AWS SDK that supports SigV4 signing. To verify whether SigV4 is supported for an AWS SDK, check the SDK release notes.

The following list shows the characters (in Unicode) allowed in your message, according to the W3C XML specification. For more information, go to http://www.w3.org/TR/REC-xml/#charsets If you send any characters not included in the list, your request will be rejected.

#x9 | #xA | #xD | [#x20 to #xD7FF] | [#xE000 to #xFFFD] | [#x10000 to #x10FFFF]

Public Method SendMessageBatch(string, List<SendMessageBatchRequestEntry>) Delivers up to ten messages to the specified queue. This is a batch version of SendMessage. The result of the send action on each message is reported individually in the response. The maximum allowed individual message size is 256 KB (262,144 bytes).

The maximum total payload size (i.e., the sum of all a batch's individual message lengths) is also 256 KB (262,144 bytes).

If the DelaySeconds parameter is not specified for an entry, the default for the queue is used.

The following list shows the characters (in Unicode) that are allowed in your message, according to the W3C XML specification. For more information, go to http://www.faqs.org/rfcs/rfc1321.html. If you send any characters that are not included in the list, your request will be rejected.

#x9 | #xA | #xD | [#x20 to #xD7FF] | [#xE000 to #xFFFD] | [#x10000 to #x10FFFF]

Because the batch request can result in a combination of successful and unsuccessful actions, you should check for batch errors even when the call returns an HTTP status code of 200. Some API actions take lists of parameters. These lists are specified using the param.n notation. Values of n are integers starting from 1. For example, a parameter list with two elements looks like this:

&Attribute.1=this

&Attribute.2=that

Public Method SendMessageBatch(SendMessageBatchRequest) Delivers up to ten messages to the specified queue. This is a batch version of SendMessage. The result of the send action on each message is reported individually in the response. The maximum allowed individual message size is 256 KB (262,144 bytes).

The maximum total payload size (i.e., the sum of all a batch's individual message lengths) is also 256 KB (262,144 bytes).

If the DelaySeconds parameter is not specified for an entry, the default for the queue is used.

The following list shows the characters (in Unicode) that are allowed in your message, according to the W3C XML specification. For more information, go to http://www.faqs.org/rfcs/rfc1321.html. If you send any characters that are not included in the list, your request will be rejected.

#x9 | #xA | #xD | [#x20 to #xD7FF] | [#xE000 to #xFFFD] | [#x10000 to #x10FFFF]

Because the batch request can result in a combination of successful and unsuccessful actions, you should check for batch errors even when the call returns an HTTP status code of 200. Some API actions take lists of parameters. These lists are specified using the param.n notation. Values of n are integers starting from 1. For example, a parameter list with two elements looks like this:

&Attribute.1=this

&Attribute.2=that

Public Method SetQueueAttributes(string, Dictionary<String, String>) Sets the value of one or more queue attributes. When you change a queue's attributes, the change can take up to 60 seconds for most of the attributes to propagate throughout the SQS system. Changes made to the MessageRetentionPeriod attribute can take up to 15 minutes. Going forward, new attributes might be added. If you are writing code that calls this action, we recommend that you structure your code so that it can handle new attributes gracefully.
Public Method SetQueueAttributes(SetQueueAttributesRequest) Sets the value of one or more queue attributes. When you change a queue's attributes, the change can take up to 60 seconds for most of the attributes to propagate throughout the SQS system. Changes made to the MessageRetentionPeriod attribute can take up to 15 minutes. Going forward, new attributes might be added. If you are writing code that calls this action, we recommend that you structure your code so that it can handle new attributes gracefully.

Examples

This example shows how to receive a message.

Receive message example

var client = new AmazonSQSClient();

var request = new ReceiveMessageRequest
{
  AttributeNames = new List<string>() { "All" },
  MaxNumberOfMessages = 5,
  QueueUrl = "https://sqs.us-east-1.amazonaws.com/80398EXAMPLE/MyTestQueue",
  VisibilityTimeout = (int)TimeSpan.FromMinutes(10).TotalSeconds,
  WaitTimeSeconds = (int)TimeSpan.FromSeconds(5).TotalSeconds
};

var response = client.ReceiveMessage(request);

if (response.Messages.Count > 0)
{
  foreach (var message in response.Messages)
  {
    Console.WriteLine("For message ID '" + message.MessageId + "':");
    Console.WriteLine("  Body: " + message.Body);
    Console.WriteLine("  Receipt handle: " + message.ReceiptHandle);
    Console.WriteLine("  MD5 of body: " + message.MD5OfBody);
    Console.WriteLine("  MD5 of message attributes: " +
      message.MD5OfMessageAttributes);
    Console.WriteLine("  Attributes:");

    foreach (var attr in message.Attributes)
    {
      Console.WriteLine("    " + attr.Key + ": " + attr.Value);
    }
  }
}
else
{
  Console.WriteLine("No messages received.");
}
      

Version Information

.NET Framework:
Supported in: 4.5, 4.0, 3.5

.NET for Windows Store apps:
Supported in: Windows 8.1, Windows 8

.NET for Windows Phone:
Supported in: Windows Phone 8.1, Windows Phone 8