Demystifying Cloud and Consoles..

Demystifying Cloud and Consoles..

AWS EC2 notes

AWS EC2 notes

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Hello Readers,

This is part 2 of the 5-part Series on cracking the AWS Solutions Architect - Associate Exam. Click here for part 1 - AWS S3.

I've divided the notes into a 5 part series.

EC2 Notes

EC2 Types

  • On-Demand
  • Reserved
  • Spot
  • Dedicated Hosts

Reserved Instance(RI) Types

  • Standard RI - Upfront, greater discount - No changing instance types
  • Convertible RI - lesser discount (54% off on-demand) - Changeable instance types - But should be equal or greater value
  • Scheduled RI - only needed for a fraction of day/month/year

EC2 Mnemonic ( To remember various instance types supported )


F - FPGA; I - For IOPS; G - Graphics; H - High Disk throughput; T- t2 cheap;

D - Density; R - RAM;

M - main/general purpose; C - Compute; P - Graphics; X - Xtreme memory; Z - Xtreme memory and CPU;

A - ARM-based workloads; U - Bare metal;

EC2 general notes:

  • General-purpose SSD can have 100 burstable up to 3000 IOPS.
  • 3 IOPS / GB
  • NOW, Root Volume can be encrypted during EC2 creation
  • Root Volume has 3 options

    • (gp2) General-purpose SSD
    • (io1) Provisioned IOPS SSD
    • (Standard) Magnetic
  • But, Additional EBS volume has 5 options

    • (gp2) General-purpose SSD [ Most workloads ]
    • (io1) Provisioned IOPS SSD [ Databases ]
    • (standard) Magnetic [Infrequently accessed Workloads] - PREVIOUS GEN
    • (sc1) Cold HDD [ Cheapest storage; File Servers]
    • (st1) Throughput optimized HDD [ Used in Data-warehousing ]

image.png Image Credit

  • Security groups are Stateful - That means if you create inbound rules, then it automatically presumes outbound as well. Unlike NACL, which is Stateless- You MUST mention outbound specifically.
  • EBS Snapshots exists on S3
  • Snapshots are incremental - only the last blocks that have changed since your last snapshot are only moved to S3.
  • EBS vs Instance Store
    • For EBS backed Instance: Root device of an instance (from the AMI) is basically an Amazon EBS volumes that are created from EBS snapshots
    • For Instance Store backed Instance: Root device of an instance (from the AMI) is basically created from a template store in S3.
    • Instance Store: You cannot stop; you can only reboot/terminate. Also, Instance Store doesn't have Volume attached to it.
    • In both storage format - if you reboot, you won’t lose data
  • ENI (Elastic Network Interface)
    • For basic networking up to 10Gbps
  • ENA (Elastic Network Adapter) - Uses SR- IOV (Single Root I/O Virtualization)
    • Supports up to 100 Gbps N/w speeds [In Older-gen, Virtual Function(VF) is used, which supports only up to 10 Gbps]
  • EFA (Elastic Fabric Adapter)
    • Can be attached to EC2 for High perf computing(HPC) or ML application

Note: You can only share unencrypted EBS snapshots as public. But encrypted cannot be shared as a snapshot or AMI.

  • Cloudwatch with EC2 can monitor
    • CPU
    • Network
    • Disk
    • Status Checks
  • Curl to get instance specific information (Also, try replacing meta-data with user-data ).
  • EFS
    • It supports network file system version 4 (NFSv4) protocol
    • Designed for Linux & Unix.
    • you only pay for the storage you use. (No pre-provisioning cost)
    • Read after write consistency
  • FSX for Windows
    • A managed windows server that runs Windows Server message block (SMB) based file servers
    • Designed for windows & windows applications
    • Supports AD users ACL, group & security policies, DFS, and replication
  • FSX for Lustre.
    • For compute-intensive, ML, HPC millions of IOPS.
    • Stores directly on S3.
  • 3 types of Placement groups
    • Clustered ( single AZ ) - For low latency, High N/w
    • Spread ( Single instance in each AZ, So separate AZ ) - To avoid hardware failure
    • Partitioned (multiple instances in each AZ, So separate partitioned AZ )
  • The hypervisor used in EC2
    • Xen (previously used)
    • Nitro (Currently used, It’s AWS’ own hypervisor)
  • Standard RI cannot be moved between regions
  • In the Spread Placement group, Each AZ can have a max of 7 EC2 instances only.

Continue reading Part 3 - AWS Databases ...

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