AWS Cloud Trail

AWS CloudTrail is an AWS service that helps you enable governance, compliance, and operational and risk auditing of your AWS account.

Actions taken by a user, role, or an AWS service are recorded as events in CloudTrail.

  • Events include actions taken in the AWS Management Console, AWS Command Line Interface, and AWS SDKs and APIs.

CloudTrail is enabled on your AWS account when you create it. (but not cloud Trail Logging)

When activity occurs in your AWS account, that activity is recorded in a Cloud Trail event.

  • You can…



SNS is a fast, flexibility, fully managed push notification service

Its a web service that coordinates and manages the delivery or sending of messages (from the cloud) to subscribing endpoints or clients.

It allows for sending individual messages or fan-out messages to a large number of recipients or other distributed AWS services.

  • Messages published to an SNS topics will be delivered to the subscribers immediately.

SNS allows you to:

  • Send push messages ( not poll messages like SQS)
  • Scale as your needs grow
  • Engage audiences directly or all at once
  • Deliver messages…

AWS: Amazon Aurora

Aurora Read Replicas

Up to 15 Aurora Replicas can be distributed across the Availability Zones

  • DB cluster volume is made up of multiple copies of the data for the DB cluster
  • The data in the cluster volume is represented as a single, logical volume to the primary instance and to Aurora Replicas in the DB cluster

Due to this cluster volumes architecture, Aurora Replicas can return the same data for query results with minimal replica lag

  • Usually much less than 100 milliseconds after the primary instance has written an update.
  • Because the cluster volume is shared among…

AWS: RDS (Relational Database Service)

Manual Backup (Snapshots)

Are not used for point in time recovery

Are user initiated, not RDS service initiated

Stored in Amazon S3

They are not deleted automatically when you delete your RDS instance, rather, they wills tay on S3 until you go ahead and delete them.

It is recommended to take a final snapshot before deleting your RDS DB instance

  • It comes in handy if you want to restore your DB instance in the future.

Can be shared with other AWS accounts directly.

DB Automated Backups- Restore/Recovery

You can specify a point-in-time restore to any…

AWS: RDS (Relational Database Service)

It is an fully managed Relational DB Engine service where aws is responsible for:

Security and patching of the DB instance

Automated backup for your DB instances

Software updates for the DB engine

Easy scaling for storage and compute as required

If selected, Multi-AZ with synchronous replication between the active and standby DB instances

Automatic fail over if Multi-AZ was selected

Providing the ability to create DB read replicas for DB read scaling (intensive read deployments)

Every DB instance has a weekly maintenance window

If you did not specify one at the time you create…

AWS:Introduction of Databases

What is Database?

Data access (reads and writes) is needed on a recruiting basis.

It allows multiple user access for reads and writes

It safeguards against unintentional mistakes, or unexpected power or hardware failure, and can recover the last known state.

Relation Database:

A relation database is a data structure that allows you to link information from different tables, or different types of data buckets.

It normalizes data into the structures.

A schema is used to strictly define, tables, columns, indexes, and relations between tables

  • Same items in tables are stored in the same table locations (rows/columns)

AWS: Auto Scaling 2nd Part

ASG Health Checks

Auto Scaling classifies its EC2 instances health status as either Healthy or Unhealthy.

By default, As uses EC2 Status Checks only to determince the health status of an instance.

When you hve one or more ELBs defined with the AS Group, you can configure Auto Scaling to use “both” the EC2 Health Checks and the ELB Health Checks to determine the Instances health status.

Health Check Grace period:

By default is 300 seconds

  • Is the time Auto Scaling waits from the time an Instance comes into service (becomes In-Service) before checking its…

AWS: Auto Scaling

It is an AWS feature that allows your AWS component needs (EC2 instances fleet) to grow or shrink depending on your workload requirements.

Auto scaling ensures that you have the right number of AWS EC2 instances for your needs at all times.

Auto Scaling helps you save cost by cutting down the number of EC2 instances when not needed, and scaling out to add more instances only when it is required.

Auto Scaling


  • Launch Configuration

It is the configuration template used to create new EC2 instances for the ASG, defines parameters like : Instance family, Instance type, AMI…

Network Load Balancer 2nd part

Client Source IP address Preservation

If you use Instance ID as target type, NLB preserves the clients source IP addresses, and provide them to the targets.

On the other hand, If you use the IP address s the target, the source IP addresses are the private IP addresses of the load balancer nodes.

  • In this case if your application require the clients source IP address, you can configure Proxy Protocol on the NLB.

If you use Instance ID as target type, NLB preserves the clients source IP addresses, and provides them to the targets.


Bharathi Batthula

Bharathi is a self driven and purpose-oriented person.The main mission is to create profound change in her career. contact her on

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