EC2

  • Elastic Cloud Computer

EC2 User Data

  • Scripts that runs when the instance is booted up
  • Use for
  • Installing updates while boot up
  • Installing software while boot up
  • Download common files while boot up
  • These scripts are run as root user
  • like sudo command
  • Scripts are executed with root user previleges

EC2 Meta Data

  • Information about the instance

Launch Type

  • On Demand
  • Pay as you go
  • Reserved
  • 3 types in terms of duration
    • Regular Reserved Instance
    • Min 1 to max 3 Years
    • Convertible Reserved Instance
    • Can be convert the types like more cpu optimized, more memory optimized
    • Scheduled Reserved Instance
    • Will be up and running for certain times in regular basis
    • Recommended when the time frame is at least 1 year usage
  • 2 types in terms of capacity reservation
    • Zonal - Allow capacity reservation, applicable for availability zones reserve instances
    • Regional - Allow capacity reservation, applicable for regional reserve instances
  • Spot Instance
  • can loose instance
  • very low price
  • Define max spot price
  • if the current spot price goes high of the defined spot price, we loose the instance in 2 minutes
  • Using Spot Block we can extend the termination delay till -6 hours
  • Two type of request
    • One time request
    • Once max price < current price, all instances are removed
    • Persistent Request
    • If spot instances stop and then things are good, these instances launched automatically
      • To stop persistent request
      • First delete the spot request
      • Then removed the spot instances
  • Spot Fleets
    • Set of
    • Spot Instances and On-Demand Instances
    • We can define
    • Possible launch pools
      • Multiple AZ
      • Various type of instance
      • Various OS
    • Automatically stops when meed the capacity
    • It offers
    • lowestPrice
    • diversified (distribute across az and workloads)
    • capacityOptimized
  • Dedicated Instance
  • Does not share hardware
  • Dedicated Host
  • Does not share server, entire placement is booked

Dedicated Instance Vs Dedicated Host

  • In Dedicated Instance
  • The billing is is done per instance
  • The other instance of same account, may share hardware
  • No control over placement group
  • In Dedicated Host, billing is on whole Dedicated Host
  • Control over placement group

Instance Type

  • R
  • Instance with lots of memory/RAM
  • Used when in memory caching is required
  • C
  • Instance with good Computation Power
  • Used for DB Server
  • M
  • Middle between RAM and Computation
  • Used for Application Server / General Application
  • Has 10-25 GB/s networking
  • Has ENA enabled
  • Low latency network with NVME ebs
  • I
  • For heave I/O Application
  • Used for DB
  • When good Instance Storage is required
  • G
  • GPU optimized instance
  • Used for video rendering or machine learning
  • T2/T3
  • Burstble instance
  • Provide good performance according to the capacity
  • There is a criteria, where unlimited burst is provided

Terminating a EC2 Instance

  • For production EC2 Instance
  • Need a tag
  • In resource level there should be explicit deny for production tag for not to terminates