- Message queue is a queue of messages exchanged between applications
- SQS is a highly reliable, scalable and distributed message queuing service => messaging platform
- Standard queue:
- provide best-effort ordering which ensures that messages are deliveried in the same order as they are sent. Occasionally, more than one copy of a message might be deliveried out of order because highly-distributed architecutre wich high throughput
- FIFO queue:
- offer FIFO delivery and exactly-once processing
- remains available until a consumer processes and deletes it
- is used by other queues for storing failed messages that are not successfully consumed by consumer process
- Redundant infrastructure: it ensures that a message is deliveried
- At least once in a standard queue
- Exactly once in a First In First Out queue
- Multiple producers and consumers
- Configure each queue independently
- Variable message size:
- Message size of maximum 256KB
- If > 256KB => store S3, SQS holds the pointer to the S3 object in the queue
- Queue access control, set a delay time in a queue
- Decoupling application processes
- Application scalability
- Guaranteed message delivery with configuration of message queue such as: using only once
- Asynchronous data processing
- Building ressilience in the system
