SQS Size growing even though messages deleted is equal to messages received

问题

What can be the reason for number of messages in a SQS queue increasing if the number of messaged deleted is equal to number of messages received?

回答1:

From Available CloudWatch Metrics for Amazon SQS - Amazon Simple Queue Service:

• NumberOfMessagesDeleted: Amazon SQS emits the NumberOfMessagesDeleted metric for every successful deletion operation that uses a valid receipt handle, including duplicate deletions.
• NumberOfMessagesReceived: The number of messages returned by calls to the ReceiveMessage action.
• NumberOfMessagesSent: The number of messages added to a queue.

Or, in simple terms:

• Sent means sent to the queue
• Received means retrieved from the queue
• Deleted means removed from the queue

来源：https://stackoverflow.com/questions/57714193/sqs-size-growing-even-though-messages-deleted-is-equal-to-messages-received