AWS Development Essentials

Long polling: This allows SQS to wait before sending a response until the message is available in the queue

Short polling: While retrieving messages from the queue, Amazon SQS will sample a subset of the servers and give messages only from those servers. This means that your specific raised request might not return all the messages from the queue

your messages will be replicated on multiple servers to give you the advantage of High Availability (HA) and redundancy. However, because of this, if something goes wrong, AWS won't delete your message from any server and you will receive that message more than once.

f you choose Exponential, then a retry will be made for an exponential period of time. For example, the first retry will be made after 2 seconds, the second retry will be made after 4 seconds, then 8 seconds, then 16 seconds, and so on.

Authorization: This is what you're permitted to look at once the cloud grants you access to services.

Authentication: This is how you demonstrate your uniqueness avowal.

The Hash and Range keys are the two attribute types that act as the (compound) primary key. The Range key must be accompanied by the Hash key, but the Hash key can optionally be accompanied by the Range key. The Hash key is an attribute type that every table must have. The Hash key is an unordered collection of items; this means that the items with the same Hash key values will go to the same partition, but there won't be any ordering based on these Hash keys. Whereas, on the other hand, items will always be ordered on their Range key values (but grouped with the Hash key values).

In general, AMIs backed by Amazon EBS are preferred, as they use persistent storage and launch faster.

Amazon EBS is a persistent storage provided by AWS

Ephemeral storage is temporary in nature. For this kind of storage, one should not depend on these disks to keep long-term production data or other important data.