The journey of a DynamoDB request

Throughout this chapter, we’ve explored various core components of DynamoDB as a distributed database. Now, let’s delve into an overview of the read and write paths, consolidating the information we have learned so far.

The journey of a read request (GetItem)

The following figure illustrates the journey of a read request within DynamoDB:

Figure 10.8 – DynamoDB read request journey

Let’s explain the flow of the previous figure:

1. A GetItem request is sent to a regional DynamoDB endpoint. Through load balancing by the service, it reaches an RR host.
2. The RR performs various validations, including authenticating and authorizing the caller. It verifies that the caller entity (such as an IAM user or role) has the necessary permissions to perform the requested operation on the specified table. Additionally, the RR validates the request parameters, such as schema compliance, table name...