AWSSQSReceiveMessageRequest
Objective-C
@interface AWSSQSReceiveMessageRequest
Swift
class AWSSQSReceiveMessageRequest
-
A list of attributes that need to be returned along with each message. These attributes include:
All
– Returns all values.ApproximateFirstReceiveTimestamp
– Returns the time the message was first received from the queue (epoch time in milliseconds).ApproximateReceiveCount
– Returns the number of times a message has been received across all queues but not deleted.AWSTraceHeader
– Returns the X-Ray trace header string.SenderId
For a user, returns the user ID, for example
ABCDEFGHI1JKLMNOPQ23R
.For an IAM role, returns the IAM role ID, for example
ABCDE1F2GH3I4JK5LMNOP:i-a123b456
.
SentTimestamp
– Returns the time the message was sent to the queue (epoch time in milliseconds).SqsManagedSseEnabled
– Enables server-side queue encryption using SQS owned encryption keys. Only one server-side encryption option is supported per queue (for example, SSE-KMS or SSE-SQS).MessageDeduplicationId
– Returns the value provided by the producer that calls theSendMessage
action.MessageGroupId
– Returns the value provided by the producer that calls theSendMessage
action. Messages with the sameMessageGroupId
are returned in sequence.SequenceNumber
– Returns the value provided by Amazon SQS.
Declaration
Objective-C
@property (nonatomic, strong) NSArray<NSString *> *_Nullable attributeNames;
Swift
var attributeNames: [String]? { get set }
-
The maximum number of messages to return. Amazon SQS never returns more messages than this value (however, fewer messages might be returned). Valid values: 1 to 10. Default: 1.
Declaration
Objective-C
@property (nonatomic, strong) NSNumber *_Nullable maxNumberOfMessages;
Swift
var maxNumberOfMessages: NSNumber? { get set }
-
The name of the message attribute, where N is the index.
The name can contain alphanumeric characters and the underscore (
_
), hyphen (-
), and period (.
).The name is case-sensitive and must be unique among all attribute names for the message.
The name must not start with AWS-reserved prefixes such as
AWS.
orAmazon.
(or any casing variants).The name must not start or end with a period (
.
), and it should not have periods in succession (..
).The name can be up to 256 characters long.
When using
ReceiveMessage
, you can send a list of attribute names to receive, or you can return all of the attributes by specifyingAll
or.*
in your request. You can also use all message attributes starting with a prefix, for examplebar.*
.Declaration
Objective-C
@property (nonatomic, strong) NSArray<NSString *> *_Nullable messageAttributeNames;
Swift
var messageAttributeNames: [String]? { get set }
-
The URL of the Amazon SQS queue from which messages are received.
Queue URLs and names are case-sensitive.
Declaration
Objective-C
@property (nonatomic, strong) NSString *_Nullable queueUrl;
Swift
var queueUrl: String? { get set }
-
This parameter applies only to FIFO (first-in-first-out) queues.
The token used for deduplication of
ReceiveMessage
calls. If a networking issue occurs after aReceiveMessage
action, and instead of a response you receive a generic error, it is possible to retry the same action with an identicalReceiveRequestAttemptId
to retrieve the same set of messages, even if their visibility timeout has not yet expired.You can use
ReceiveRequestAttemptId
only for 5 minutes after aReceiveMessage
action.When you set
FifoQueue
, a caller of theReceiveMessage
action can provide aReceiveRequestAttemptId
explicitly.If a caller of the
ReceiveMessage
action doesn’t provide aReceiveRequestAttemptId
, Amazon SQS generates aReceiveRequestAttemptId
.It is possible to retry the
ReceiveMessage
action with the sameReceiveRequestAttemptId
if none of the messages have been modified (deleted or had their visibility changes).During a visibility timeout, subsequent calls with the same
ReceiveRequestAttemptId
return the same messages and receipt handles. If a retry occurs within the deduplication interval, it resets the visibility timeout. For more information, see Visibility Timeout in the Amazon SQS Developer Guide.If a caller of the
ReceiveMessage
action still processes messages when the visibility timeout expires and messages become visible, another worker consuming from the same queue can receive the same messages and therefore process duplicates. Also, if a consumer whose message processing time is longer than the visibility timeout tries to delete the processed messages, the action fails with an error.To mitigate this effect, ensure that your application observes a safe threshold before the visibility timeout expires and extend the visibility timeout as necessary.
While messages with a particular
MessageGroupId
are invisible, no more messages belonging to the sameMessageGroupId
are returned until the visibility timeout expires. You can still receive messages with anotherMessageGroupId
as long as it is also visible.If a caller of
ReceiveMessage
can’t track theReceiveRequestAttemptId
, no retries work until the original visibility timeout expires. As a result, delays might occur but the messages in the queue remain in a strict order.
The maximum length of
ReceiveRequestAttemptId
is 128 characters.ReceiveRequestAttemptId
can contain alphanumeric characters (a-z
,A-Z
,0-9
) and punctuation (!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~
).For best practices of using
ReceiveRequestAttemptId
, see Using the ReceiveRequestAttemptId Request Parameter in the Amazon SQS Developer Guide.Declaration
Objective-C
@property (nonatomic, strong) NSString *_Nullable receiveRequestAttemptId;
Swift
var receiveRequestAttemptId: String? { get set }
-
The duration (in seconds) that the received messages are hidden from subsequent retrieve requests after being retrieved by a
ReceiveMessage
request.Declaration
Objective-C
@property (nonatomic, strong) NSNumber *_Nullable visibilityTimeout;
Swift
var visibilityTimeout: NSNumber? { get set }
-
The duration (in seconds) for which the call waits for a message to arrive in the queue before returning. If a message is available, the call returns sooner than
WaitTimeSeconds
. If no messages are available and the wait time expires, the call returns successfully with an empty list of messages.To avoid HTTP errors, ensure that the HTTP response timeout for
ReceiveMessage
requests is longer than theWaitTimeSeconds
parameter. For example, with the Java SDK, you can set HTTP transport settings using the NettyNioAsyncHttpClient for asynchronous clients, or the ApacheHttpClient for synchronous clients.Declaration
Objective-C
@property (nonatomic, strong) NSNumber *_Nullable waitTimeSeconds;
Swift
var waitTimeSeconds: NSNumber? { get set }