当使用FIFO队列时，SQS将在保留原始消息顺序方面提供有限的“最佳努力”。如果消息被发送到Dead-Letter队列（DLQ），该消息的顺序将由发送到DLQ队列的所有消息的顺序决定。因此，如果一个消息在队列上卡住并且被发送到DLQ，它将在DLQ队列中按照原来消息在FIFO队列中的顺序排列。

以下是一个使用Python的代码示例，用于测试这种情况：

import boto3 import json

sqs_client = boto3.client('sqs')

queue_url = 'https://sqs.us-west-2.amazonaws.com/111111111111/test.fifo' dlq_queue_url = 'https://sqs.us-west-2.amazonaws.com/111111111111/test-dlq.fifo'

NUM_OF_MESSAGES = 10

Send messages to SQS queue

for i in range(NUM_OF_MESSAGES): response = sqs_client.send_message( QueueUrl=queue_url, MessageGroupId='test_group', MessageDeduplicationId=f'test_msg_{i}', MessageBody=f'Test message {i}', ) print('Sent message:', response['MessageId'])

Receive messages from SQS queue

response = sqs_client.receive_message( QueueUrl=queue_url, MaxNumberOfMessages=NUM_OF_MESSAGES, WaitTimeSeconds=3, )

Simulate a message getting stuck in DLQ

if response['ResponseMetadata']['HTTPStatusCode'] == 200: message = response['Messages'][0] receipt_handle = message['ReceiptHandle'] response = sqs_client.change_message_visibility( QueueUrl=queue_url, ReceiptHandle=receipt_handle, VisibilityTimeout=0, ) print('Simulating a message getting stuck in DLQ:', message['MessageId'])

# Move message to DLQ
response = sqs_client.send_message(
    QueueUrl=dlq_queue_url,
    MessageGroupId='test_group',
    MessageDeduplicationId=message['MessageId'],
    MessageBody=message['Body'],
)
print('Moved message to DLQ:', response['MessageId'])

Receive messages from DLQ

response = sqs_client.receive_message( QueueUrl=dlq_queue_url, MaxNumberOfMessages=NUM_OF_MESSAGES, WaitTimeSeconds=3, )

if response['ResponseMetadata']['HTTPStatusCode'] == 200: print('Received messages from DL