AWS

Lambda Link to heading

Observability Link to heading

• AWS Lambda Powertools (Python)
• honeycomb-lambda-extension
• OpenTelemetry Automatic Instrumentation (Python)
• AWS Service Lens
• AWS X-Ray

RDS Link to heading

• Terraform modules
  • RDS - https://registry.terraform.io/modules/terraform-aws-modules/rds/aws/latest
  • Aurora - https://registry.terraform.io/modules/terraform-aws-modules/rds-aurora/aws/latest

Aurora Link to heading

Replicas Link to heading

• Auto scalling increases replicas when necessary.
• Aurora has 1 writer and up to 15 read replicas.

Write operations are managed by the primary instance.

The Aurora Replicas can be distributed across the Availability Zones that a DB cluster spans within an AWS Region.

If the writer instance in a cluster becomes unavailable, Aurora automatically promotes one of the reader instances to take its place as the new writer.

https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/Aurora.Replication.html#Aurora.Replication.Replicas

Vertical scale Link to heading

It can take 15 minutes or more to complete the change to a different DB instance class.

https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraPostgreSQL.Managing.html#AuroraPostgreSQL.Managing.Performance.InstanceScaling

• How to scale the writer replica vertically with minimal downtime?

(1) add an Aurora Replica to your cluster, … choose the DB instance class size that you want to use for your cluster.

(2) When the Aurora Replica is synchronized with the cluster, you then failover to the newly added Replica.

https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraPostgreSQL.Managing.html#AuroraPostgreSQL.Managing.Performance.InstanceScaling

Tunning Link to heading

• Managing query execution plans (…) - https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraPostgreSQL.Optimize.html

Serverless Link to heading

v2 writers and readers don’t scale all the way down to zero ACUs. (minimum is 0.5 ACU)

(…) v1 (..) can pause after a period of idleness, but then takes some time to resume when you open a new connection.

https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/aurora-serverless-v2.how-it-works.html#aurora-serverless-v2.how-it-works.scaling

S3 Link to heading

Versioning Link to heading

• How am I charged for using Versioning?

Normal Amazon S3 rates apply for every version of an object stored or requested.

from https://aws.amazon.com/s3/faqs/