Network.AWS.SQS.ReceiveMessage

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, see RFC1321 .
• 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 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 SQS Developer Guide .

A message that is not deleted or a message whose visibility is not 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.

Creating a Request

receiveMessage

Arguments

:: Text

rmQueueURL

-> ReceiveMessage

Creates a value of ReceiveMessage with the minimum fields required to make a request.

Use one of the following lenses to modify other fields as desired:

• rmReceiveRequestAttemptId - 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 . Important: If a caller of the ReceiveMessage action is still processing messages when the visibility timeout expires and messages become visible, another worker reading from the same queue can receive the same messages and therefore process duplicates. Also, if a reader 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 will work until the original visibility timeout expires. As a result, delays might occur but the messages in the queue will 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 .
• rmVisibilityTimeout - The duration (in seconds) that the received messages are hidden from subsequent retrieve requests after being retrieved by a ReceiveMessage request.
• rmMessageAttributeNames - The name of the message attribute, where N is the index. The message attribute name can contain the following characters: A-Z, a-z, 0-9, underscore (_), hyphen (-), and period (.). The name must not start or end with a period, and it should not have successive periods. The name is case sensitive and must be unique among all attribute names for the message. The name can be up to 256 characters long. The name can't start with "AWS." or "Amazon." (or any variations in casing), because these prefixes are reserved for use by Amazon Web Services. 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 "bar.*" to return all message attributes starting with the "bar" prefix.
• rmWaitTimeSeconds - The duration (in seconds) for which the call will wait for a message to arrive in the queue before returning. If a message is available, the call will return sooner than WaitTimeSeconds.
• rmAttributeNames - 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 sender that calls the SendMessage action. * MessageGroupId - Returns the value provided by the sender that calls the SendMessage action. Messages with the same MessageGroupId are returned in sequence. * SequenceNumber - Returns the value provided by Amazon SQS. Any other valid special request parameters (such as the following) that are specified are ignored: * ApproximateNumberOfMessages * ApproximateNumberOfMessagesDelayed * ApproximateNumberOfMessagesNotVisible * CreatedTimestamp * ContentBasedDeduplication * DelaySeconds * LastModifiedTimestamp * MaximumMessageSize * MessageRetentionPeriod * Policy * QueueArn , * ReceiveMessageWaitTimeSeconds * RedrivePolicy * FifoQueue * VisibilityTimeout
• rmMaxNumberOfMessages - The maximum number of messages to return. Amazon SQS never returns more messages than this value but might return fewer. Values can be from 1 to 10. Default is 1. All of the messages are not necessarily returned.
• rmQueueURL - The URL of the Amazon SQS queue to take action on. Queue URLs are case-sensitive.

data ReceiveMessage

See: receiveMessage smart constructor.

Instances

Eq ReceiveMessage

Methods

(==) :: ReceiveMessage -> ReceiveMessage -> Bool

(/=) :: ReceiveMessage -> ReceiveMessage -> Bool

Data ReceiveMessage

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ReceiveMessage -> c ReceiveMessage

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c ReceiveMessage

toConstr :: ReceiveMessage -> Constr

dataTypeOf :: ReceiveMessage -> DataType

dataCast1 :: Typeable (* -> *) t => (forall d. Data d => c (t d)) -> Maybe (c ReceiveMessage)

dataCast2 :: Typeable (* -> * -> *) t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c ReceiveMessage)

gmapT :: (forall b. Data b => b -> b) -> ReceiveMessage -> ReceiveMessage

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ReceiveMessage -> r

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ReceiveMessage -> r

gmapQ :: (forall d. Data d => d -> u) -> ReceiveMessage -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> ReceiveMessage -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> ReceiveMessage -> m ReceiveMessage

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ReceiveMessage -> m ReceiveMessage

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ReceiveMessage -> m ReceiveMessage

Read ReceiveMessage

Methods

readsPrec :: Int -> ReadS ReceiveMessage

readList :: ReadS [ReceiveMessage]

readPrec :: ReadPrec ReceiveMessage

readListPrec :: ReadPrec [ReceiveMessage]

Show ReceiveMessage

Methods

showsPrec :: Int -> ReceiveMessage -> ShowS

show :: ReceiveMessage -> String

showList :: [ReceiveMessage] -> ShowS

Generic ReceiveMessage

Associated Types

type Rep ReceiveMessage :: * -> *

Methods

from :: ReceiveMessage -> Rep ReceiveMessage x

to :: Rep ReceiveMessage x -> ReceiveMessage

Hashable ReceiveMessage

Methods

hashWithSalt :: Int -> ReceiveMessage -> Int

hash :: ReceiveMessage -> Int

NFData ReceiveMessage

Methods

rnf :: ReceiveMessage -> ()

AWSRequest ReceiveMessage

Associated Types

type Rs ReceiveMessage :: *

Methods

request :: ReceiveMessage -> Request ReceiveMessage

response :: MonadResource m => Logger -> Service -> Proxy * ReceiveMessage -> ClientResponse -> m (Response ReceiveMessage)

ToPath ReceiveMessage

Methods

toPath :: ReceiveMessage -> ByteString

ToHeaders ReceiveMessage

Methods

toHeaders :: ReceiveMessage -> [Header]

ToQuery ReceiveMessage

Methods

toQuery :: ReceiveMessage -> QueryString

type Rep ReceiveMessage

type Rep ReceiveMessage = D1 (MetaData "ReceiveMessage" "Network.AWS.SQS.ReceiveMessage" "amazonka-sqs-1.4.5-4rQHB5Mk9mo8cQvbOgAp4I" False) (C1 (MetaCons "ReceiveMessage'" PrefixI True) ((:*:) ((:*:) (S1 (MetaSel (Just Symbol "_rmReceiveRequestAttemptId") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe Text))) ((:*:) (S1 (MetaSel (Just Symbol "_rmVisibilityTimeout") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe Int))) (S1 (MetaSel (Just Symbol "_rmMessageAttributeNames") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe [Text]))))) ((:*:) ((:*:) (S1 (MetaSel (Just Symbol "_rmWaitTimeSeconds") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe Int))) (S1 (MetaSel (Just Symbol "_rmAttributeNames") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe [MessageAttribute])))) ((:*:) (S1 (MetaSel (Just Symbol "_rmMaxNumberOfMessages") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe Int))) (S1 (MetaSel (Just Symbol "_rmQueueURL") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 Text))))))

type Rs ReceiveMessage

type Rs ReceiveMessage = ReceiveMessageResponse

Request Lenses

rmReceiveRequestAttemptId :: Lens' ReceiveMessage (Maybe Text)

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 . Important: If a caller of the ReceiveMessage action is still processing messages when the visibility timeout expires and messages become visible, another worker reading from the same queue can receive the same messages and therefore process duplicates. Also, if a reader 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 will work until the original visibility timeout expires. As a result, delays might occur but the messages in the queue will 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 .

rmVisibilityTimeout :: Lens' ReceiveMessage (Maybe Int)

The duration (in seconds) that the received messages are hidden from subsequent retrieve requests after being retrieved by a ReceiveMessage request.

rmMessageAttributeNames :: Lens' ReceiveMessage [Text]

The name of the message attribute, where N is the index. The message attribute name can contain the following characters: A-Z, a-z, 0-9, underscore (_), hyphen (-), and period (.). The name must not start or end with a period, and it should not have successive periods. The name is case sensitive and must be unique among all attribute names for the message. The name can be up to 256 characters long. The name can't start with "AWS." or "Amazon." (or any variations in casing), because these prefixes are reserved for use by Amazon Web Services. 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 "bar.*" to return all message attributes starting with the "bar" prefix.

rmWaitTimeSeconds :: Lens' ReceiveMessage (Maybe Int)

The duration (in seconds) for which the call will wait for a message to arrive in the queue before returning. If a message is available, the call will return sooner than WaitTimeSeconds.

rmAttributeNames :: Lens' ReceiveMessage [MessageAttribute]

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 sender that calls the SendMessage action. * MessageGroupId - Returns the value provided by the sender that calls the SendMessage action. Messages with the same MessageGroupId are returned in sequence. * SequenceNumber - Returns the value provided by Amazon SQS. Any other valid special request parameters (such as the following) that are specified are ignored: * ApproximateNumberOfMessages * ApproximateNumberOfMessagesDelayed * ApproximateNumberOfMessagesNotVisible * CreatedTimestamp * ContentBasedDeduplication * DelaySeconds * LastModifiedTimestamp * MaximumMessageSize * MessageRetentionPeriod * Policy * QueueArn , * ReceiveMessageWaitTimeSeconds * RedrivePolicy * FifoQueue * VisibilityTimeout

rmMaxNumberOfMessages :: Lens' ReceiveMessage (Maybe Int)

The maximum number of messages to return. Amazon SQS never returns more messages than this value but might return fewer. Values can be from 1 to 10. Default is 1. All of the messages are not necessarily returned.

rmQueueURL :: Lens' ReceiveMessage Text

The URL of the Amazon SQS queue to take action on. Queue URLs are case-sensitive.

Destructuring the Response

receiveMessageResponse

Arguments

:: Int

rmrsResponseStatus

-> ReceiveMessageResponse

Creates a value of ReceiveMessageResponse with the minimum fields required to make a request.

Use one of the following lenses to modify other fields as desired:

• rmrsMessages - A list of messages.
• rmrsResponseStatus - -- | The response status code.

data ReceiveMessageResponse

A list of received messages.

See: receiveMessageResponse smart constructor.

Instances

Eq ReceiveMessageResponse

Methods

(==) :: ReceiveMessageResponse -> ReceiveMessageResponse -> Bool

(/=) :: ReceiveMessageResponse -> ReceiveMessageResponse -> Bool

Data ReceiveMessageResponse

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ReceiveMessageResponse -> c ReceiveMessageResponse

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c ReceiveMessageResponse

toConstr :: ReceiveMessageResponse -> Constr

dataTypeOf :: ReceiveMessageResponse -> DataType

dataCast1 :: Typeable (* -> *) t => (forall d. Data d => c (t d)) -> Maybe (c ReceiveMessageResponse)

dataCast2 :: Typeable (* -> * -> *) t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c ReceiveMessageResponse)

gmapT :: (forall b. Data b => b -> b) -> ReceiveMessageResponse -> ReceiveMessageResponse

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ReceiveMessageResponse -> r

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ReceiveMessageResponse -> r

gmapQ :: (forall d. Data d => d -> u) -> ReceiveMessageResponse -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> ReceiveMessageResponse -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> ReceiveMessageResponse -> m ReceiveMessageResponse

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ReceiveMessageResponse -> m ReceiveMessageResponse

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ReceiveMessageResponse -> m ReceiveMessageResponse

Read ReceiveMessageResponse

Methods

readsPrec :: Int -> ReadS ReceiveMessageResponse

readList :: ReadS [ReceiveMessageResponse]

readPrec :: ReadPrec ReceiveMessageResponse

readListPrec :: ReadPrec [ReceiveMessageResponse]

Show ReceiveMessageResponse

Methods

showsPrec :: Int -> ReceiveMessageResponse -> ShowS

show :: ReceiveMessageResponse -> String

showList :: [ReceiveMessageResponse] -> ShowS

Generic ReceiveMessageResponse

Associated Types

type Rep ReceiveMessageResponse :: * -> *

Methods

from :: ReceiveMessageResponse -> Rep ReceiveMessageResponse x

to :: Rep ReceiveMessageResponse x -> ReceiveMessageResponse

NFData ReceiveMessageResponse

Methods

rnf :: ReceiveMessageResponse -> ()

type Rep ReceiveMessageResponse

type Rep ReceiveMessageResponse = D1 (MetaData "ReceiveMessageResponse" "Network.AWS.SQS.ReceiveMessage" "amazonka-sqs-1.4.5-4rQHB5Mk9mo8cQvbOgAp4I" False) (C1 (MetaCons "ReceiveMessageResponse'" PrefixI True) ((:*:) (S1 (MetaSel (Just Symbol "_rmrsMessages") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe [Message]))) (S1 (MetaSel (Just Symbol "_rmrsResponseStatus") NoSourceUnpackedness SourceStrict DecidedUnpack) (Rec0 Int))))

Response Lenses

rmrsMessages :: Lens' ReceiveMessageResponse [Message]

A list of messages.

rmrsResponseStatus :: Lens' ReceiveMessageResponse Int

• - | The response status code.