AWS

AWS SAA Certification Prep – 2018

I’m getting ready to take the AWS Solutions Architect Associate 2018 test.  Below are some final items I need to review before the exam.

AWS FAQ’s:

Specific Items:

  • Spot vs Spot Block
  • Application ELB vs Classic ELB
  • Convertible vs. Standard Reserved Instances
  • EBS Cost vs Performance
  • EC2 reverse proxy (link) (link)
  • Glacier Retrieval Options
  • Beanstalk vs. NGINX
  • Cross-region snapshots for databases

AWS Developer Certification – My Plan

Below is my plan to obtain the AWS Developer Certification.

For each of the following areas listed further down, I am trying to do the following:

  • Read the FAQ’s
  • Practice in the console
  • Practice with the CLI and understand the functions\parameters
  • Review all HTTP codes
  • Review all defaults and limits
  • Review uniqueness of each area

Here are the areas I am covering in preparation for the exam.

  • EC2
  • S3
  • DynamoDB
  • SNS
  • SQS
  • VPC
  • ELB
  • Lambda
  • Route 53
  • RDS
  • SWF
  • Cloudformation
  • Elastic Beanstalk
  • API Gateway
  • Storage Gateway
  • EFS
  • CloudWatch
  • CloudTrail
  • IAM

The exam is only 55 questions, so i’m not sure how in depth the exam will go on each of these.  Regardless, its a good to review all of the areas!

AWS Consistency Models

S3 Consistency Model

  • Puts (New record) = Read-after-write consistency model
  • Updates and Deletes = Eventual consistency model

DynamoDB Consistency Model

  • Write = Eventual consistency model
  • Read = Eventual consistency model
  • Read  = Optional – Strong consistency model

Definitions

  • Read-after-write consistency model = New objects should be available with out delays to clients.
  • Eventual consistency model = “Eventually” all access attempts to a particular item will return the last updated value.  There is potential here for stale or old data reads while data replication occurs.
  • Strong consistency model = All access attempts (e.g. parallel) to a particular item return the same unique state.  Old\stale data reads are avoided, but it will cost you more.

Good information to know for any AWS certification tests…. 🙂

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AWS DynamoDB Throughput Capacity

Calculating throughput capacity!

Read capacity units

  • 1 strong consistent read per second up to 4 KB item
  • 2 eventually consistent reads per second up to 4 KB item

Write capacity unit

  • 1 write per second for an item up to 1 KB in size

Example: 1000 writes per 10 seconds @ 512 bytes evenly distributed.

Solution: 1000\10 = 100, 512 bytes rounded up = 1 KB, 100 write units

Good certification exam information… 🙂

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AWS Linux 2 – VirtualBox

So you want to run the AWS Linux 2 OS on your laptop for development purposes?  Its no problem now!

I followed the instructions (here) to get Linux 2 running with a VirtualBox VM.

These are the high-level steps I took.

  1. Create a cloud-init configuration ISO
    • Create my user-data and meta-data files
    • Validate the user-data YAML file syntax in a validator (important)
    • Create a new ISO with these 2 files on a linux server using genisoimage
      • genisoimage -output mySeed.iso -volid cidata -joliet – rock user-data meta-data
  2. Download the latest Linux 2 vdi file from AWS
  3. Copy the ISO file back to my Windows machine
  4. Create my new VM in VirtualBox (Linux\Other Linux 64-bit) using the new ISO and the downloaded vdi
    • IDE Primary Master = Linux 2 vdi file
    • IDE Secondary Master (Optical) = mySeed ISO file

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Now you should be able to startup your VM and connect via any user defined in your user-data file.

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