Retrieves one or more messages (up to 10), from the specified queue.
Using the WaitTimeSeconds parameter enables long-poll support. For
more information, see Amazon SQS Long Polling
in the Amazon Simple Queue Service Developer Guide.
sqs_receive_message(QueueUrl, AttributeNames, MessageAttributeNames,
MaxNumberOfMessages, VisibilityTimeout, WaitTimeSeconds,
ReceiveRequestAttemptId)[required] The URL of the Amazon SQS queue from which messages are received.
Queue URLs and names are case-sensitive.
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 from the queue but not deleted.
SenderId
For an IAM user, returns the IAM 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).
MessageDeduplicationId - Returns the value provided by the
producer that calls the <a>SendMessage</a> action.
MessageGroupId - Returns the value provided by the producer that
calls the <a>SendMessage</a> action. Messages with the same
MessageGroupId are returned in sequence.
SequenceNumber - Returns the value provided by Amazon SQS.
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. or
Amazon. (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 specifying All or
.* in your request. You can also use all message attributes starting
with a prefix, for example bar.*.
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.
The duration (in seconds) that the received messages are hidden from
subsequent retrieve requests after being retrieved by a ReceiveMessage
request.
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.
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 a ReceiveMessage action, and instead of
a response you receive a generic error, you can retry the same action
with an identical ReceiveRequestAttemptId 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 a
ReceiveMessage action.
When you set FifoQueue, a caller of the ReceiveMessage action
can provide a ReceiveRequestAttemptId explicitly.
If a caller of the ReceiveMessage action doesn't provide a
ReceiveRequestAttemptId, Amazon SQS generates a
ReceiveRequestAttemptId.
You can retry the ReceiveMessage action with the same
ReceiveRequestAttemptId 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 Simple Queue Service 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 same MessageGroupId are returned
until the visibility timeout expires. You can still receive messages
with another MessageGroupId as long as it is also visible.
If a caller of ReceiveMessage can't track the
ReceiveRequestAttemptId, 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 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 Simple Queue Service Developer Guide.
svc$receive_message(
QueueUrl = "string",
AttributeNames = list(
"All"|"Policy"|"VisibilityTimeout"|"MaximumMessageSize"|"MessageRetentionPeriod"|"ApproximateNumberOfMessages"|"ApproximateNumberOfMessagesNotVisible"|"CreatedTimestamp"|"LastModifiedTimestamp"|"QueueArn"|"ApproximateNumberOfMessagesDelayed"|"DelaySeconds"|"ReceiveMessageWaitTimeSeconds"|"RedrivePolicy"|"FifoQueue"|"ContentBasedDeduplication"|"KmsMasterKeyId"|"KmsDataKeyReusePeriodSeconds"
),
MessageAttributeNames = list(
"string"
),
MaxNumberOfMessages = 123,
VisibilityTimeout = 123,
WaitTimeSeconds = 123,
ReceiveRequestAttemptId = "string"
)
Short poll is the default behavior where a weighted random set of
machines is sampled on a ReceiveMessage call. Thus, only the messages
on the sampled machines are returned. If the number of messages in the
queue is small (fewer than 1,000), you most likely 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. If this happens, repeat the
request.
For each message returned, the response includes the following:
The message body.
An MD5 digest of the message body. For information about MD5, see RFC1321.
The MessageId you received when you sent the message to the queue.
The receipt handle.
The message attributes.
An 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 Simple Queue Service Developer Guide.
You can provide the VisibilityTimeout parameter in your request. The
parameter is applied to the messages that Amazon SQS returns in the
response. If you don't 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 Simple Queue Service Developer Guide.
A message that isn't deleted or a message whose visibility isn't extended before the visibility timeout expires counts as a failed receive. Depending on the configuration of the queue, the message might be sent to the dead-letter queue.
In the future, new attributes might be added. If you write code that calls this action, we recommend that you structure your code so that it can handle new attributes gracefully.