Unlimited queues and messages: Create unlimited Amazon SQS queues with an unlimited number of message in any region
Payload Size: Message payloads can contain up to 256KB of text in any format. Each 64KB ‘chunk’ of payload is billed as 1 request. For example, a single API call with a 256KB payload will be billed as four requests. To send messages larger than 256KB, you can use the Amazon SQS Extended Client Library for Java, which uses Amazon S3 to store the message payload. A reference to the message payload is sent using SQS.
Batches: Send, receive, or delete messages in batches of up to 10 messages or 256KB. Batches cost the same amount as single messages, meaning SQS can be even more cost effective for customers that use batching.
Long polling: Reduce extraneous polling to minimize cost while receiving new messages as quickly as possible. When your queue is empty, long-poll requests wait up to 20 seconds for the next message to arrive. Long poll requests cost the same amount as regular requests.
Retain messages in queues for up to 14 days.
Send and read messages simultaneously.
Message locking: When a message is received, it becomes “locked” while being processed. This keeps other computers from processing the message simultaneously. If the message processing fails, the lock will expire and the message will be available again.
Queue sharing: Securely share Amazon SQS queues anonymously or with specific AWS accounts. Queue sharing can also be restricted by IP address and time-of-day.
Server-side encryption (SSE): Protect the contents of messages in Amazon SQS queues using keys managed in the AWS Key Management Service (AWS KMS). SSE encrypts messages as soon as Amazon SQS receives them. The messages are stored in encrypted form and Amazon SQS decrypts messages only when they are sent to an authorized consumer.
Dead Letter Queues (DLQ): Handle messages that have not been successfully processed by a consumer with Dead Letter Queues. When the maximum receive count is exceeded for a message it will be moved to the DLQ associated with the original queue. Set up separate consumer processes for DLQs which can help analyze and understand why messages are getting stuck. DLQs must be of the same type as the source queue (standard or FIFO).