Support always reading from the local zone, regardless of the nodes role

[madolson]

Describe the feature

I was told that the AZ_AFFINITY feature only applies to replicas. So if you are running an application with 3 nodes in three AZs, if your client application is running in the same AZ as the primary, it will route to a different AZ in order to send the traffic to a replica. There should be a way to indicate that you always want to connect to the local zone.

Use Case

In many caching workloads, the application is not bottlenecked on write throughput, so the primary is not all that highly utilized. For these workloads, they will probably care more about the latency or cost dimension.

Proposed Solution

No response

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

Client version used

You ask for too much details

Environment details (OS name and version, etc.)

A Potato

[madolson]

@barshaul Related to our discussion with offerup at re:invent.

[asafpamzn]

@adarovadya please take it as part 1.3

[adarovadya]

Ill add a new strategy AZ_AFFINITY_FROM_ALL_NODES (or something similar). Please note that the user should add the client_az config. If the user updates this configuration, we will choose the new strategy by default.