Network.AWS.SQS.ReceiveMessage

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 .

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.

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 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 .
• 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 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.* .
• rmWaitTimeSeconds - 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.
• 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) are ignored: * ApproximateNumberOfMessages * ApproximateNumberOfMessagesDelayed * ApproximateNumberOfMessagesNotVisible * CreatedTimestamp * ContentBasedDeduplication * DelaySeconds * FifoQueue * LastModifiedTimestamp * MaximumMessageSize * MessageRetentionPeriod * Policy * QueueArn , * ReceiveMessageWaitTimeSeconds * RedrivePolicy * VisibilityTimeout
• rmMaxNumberOfMessages - The maximum number of messages to return. Amazon SQS never returns more messages than this value (however, fewer messages might be returned). Valid values are 1 to 10. Default is 1.
• rmQueueURL - The URL of the Amazon SQS queue from which messages are received. Queue URLs are case-sensitive.

data ReceiveMessage

See: receiveMessage smart constructor.

Instances

Eq ReceiveMessage

Defined in Network.AWS.SQS.ReceiveMessage

Methods

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

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

Data ReceiveMessage

Defined in Network.AWS.SQS.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

Defined in Network.AWS.SQS.ReceiveMessage

Methods

readsPrec :: Int -> ReadS ReceiveMessage

readList :: ReadS [ReceiveMessage]

readPrec :: ReadPrec ReceiveMessage

readListPrec :: ReadPrec [ReceiveMessage]

Show ReceiveMessage

Defined in Network.AWS.SQS.ReceiveMessage

Methods

showsPrec :: Int -> ReceiveMessage -> ShowS

show :: ReceiveMessage -> String

showList :: [ReceiveMessage] -> ShowS

Generic ReceiveMessage

Defined in Network.AWS.SQS.ReceiveMessage

Associated Types

type Rep ReceiveMessage :: Type -> Type

Methods

from :: ReceiveMessage -> Rep ReceiveMessage x

to :: Rep ReceiveMessage x -> ReceiveMessage

Hashable ReceiveMessage

Defined in Network.AWS.SQS.ReceiveMessage

Methods

hashWithSalt :: Int -> ReceiveMessage -> Int

hash :: ReceiveMessage -> Int

AWSRequest ReceiveMessage

Defined in Network.AWS.SQS.ReceiveMessage

Associated Types

type Rs ReceiveMessage :: Type

Methods

request :: ReceiveMessage -> Request ReceiveMessage

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

ToHeaders ReceiveMessage

Defined in Network.AWS.SQS.ReceiveMessage

Methods

toHeaders :: ReceiveMessage -> [Header]

ToPath ReceiveMessage

Defined in Network.AWS.SQS.ReceiveMessage

Methods

toPath :: ReceiveMessage -> ByteString

ToQuery ReceiveMessage

Defined in Network.AWS.SQS.ReceiveMessage

Methods

toQuery :: ReceiveMessage -> QueryString

NFData ReceiveMessage

Defined in Network.AWS.SQS.ReceiveMessage

Methods

rnf :: ReceiveMessage -> ()

type Rep ReceiveMessage

Defined in Network.AWS.SQS.ReceiveMessage

type Rep ReceiveMessage = D1 (MetaData "ReceiveMessage" "Network.AWS.SQS.ReceiveMessage" "amazonka-sqs-1.6.1-4KwGv5jRSGR2noZdqwtyOA" False) (C1 (MetaCons "ReceiveMessage'" PrefixI True) ((S1 (MetaSel (Just "_rmReceiveRequestAttemptId") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe Text)) :*: (S1 (MetaSel (Just "_rmVisibilityTimeout") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe Int)) :*: S1 (MetaSel (Just "_rmMessageAttributeNames") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe [Text])))) :*: ((S1 (MetaSel (Just "_rmWaitTimeSeconds") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe Int)) :*: S1 (MetaSel (Just "_rmAttributeNames") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe [MessageAttribute]))) :*: (S1 (MetaSel (Just "_rmMaxNumberOfMessages") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe Int)) :*: S1 (MetaSel (Just "_rmQueueURL") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 Text)))))

type Rs ReceiveMessage

Defined in Network.AWS.SQS.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 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 .

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 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.* .

rmWaitTimeSeconds :: Lens' ReceiveMessage (Maybe Int)

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.

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) are ignored: * ApproximateNumberOfMessages * ApproximateNumberOfMessagesDelayed * ApproximateNumberOfMessagesNotVisible * CreatedTimestamp * ContentBasedDeduplication * DelaySeconds * FifoQueue * LastModifiedTimestamp * MaximumMessageSize * MessageRetentionPeriod * Policy * QueueArn , * ReceiveMessageWaitTimeSeconds * RedrivePolicy * VisibilityTimeout

rmMaxNumberOfMessages :: Lens' ReceiveMessage (Maybe Int)

The maximum number of messages to return. Amazon SQS never returns more messages than this value (however, fewer messages might be returned). Valid values are 1 to 10. Default is 1.

rmQueueURL :: Lens' ReceiveMessage Text

The URL of the Amazon SQS queue from which messages are received. 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

Defined in Network.AWS.SQS.ReceiveMessage

Methods

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

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

Data ReceiveMessageResponse

Defined in Network.AWS.SQS.ReceiveMessage

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

Defined in Network.AWS.SQS.ReceiveMessage

Methods

readsPrec :: Int -> ReadS ReceiveMessageResponse

readList :: ReadS [ReceiveMessageResponse]

readPrec :: ReadPrec ReceiveMessageResponse

readListPrec :: ReadPrec [ReceiveMessageResponse]

Show ReceiveMessageResponse

Defined in Network.AWS.SQS.ReceiveMessage

Methods

showsPrec :: Int -> ReceiveMessageResponse -> ShowS

show :: ReceiveMessageResponse -> String

showList :: [ReceiveMessageResponse] -> ShowS

Generic ReceiveMessageResponse

Defined in Network.AWS.SQS.ReceiveMessage

Associated Types

type Rep ReceiveMessageResponse :: Type -> Type

Methods

from :: ReceiveMessageResponse -> Rep ReceiveMessageResponse x

to :: Rep ReceiveMessageResponse x -> ReceiveMessageResponse

NFData ReceiveMessageResponse

Defined in Network.AWS.SQS.ReceiveMessage

Methods

rnf :: ReceiveMessageResponse -> ()

type Rep ReceiveMessageResponse

Defined in Network.AWS.SQS.ReceiveMessage

type Rep ReceiveMessageResponse = D1 (MetaData "ReceiveMessageResponse" "Network.AWS.SQS.ReceiveMessage" "amazonka-sqs-1.6.1-4KwGv5jRSGR2noZdqwtyOA" False) (C1 (MetaCons "ReceiveMessageResponse'" PrefixI True) (S1 (MetaSel (Just "_rmrsMessages") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe [Message])) :*: S1 (MetaSel (Just "_rmrsResponseStatus") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 Int)))

Response Lenses

rmrsMessages :: Lens' ReceiveMessageResponse [Message]

A list of messages.

rmrsResponseStatus :: Lens' ReceiveMessageResponse Int

• - | The response status code.