JavaEE workshop #8 

Kuba Hejda

(Runtime of backend apps, Cloud, AWS

Scheduling, Files, Javadoc)

Content

  • What is cloud? ( baby don't hurt meee, .. )
    • Terminology
    • Delivery model
    • Deployment model
  • AWS
    • Basics
    • Console
    • EC2
    • S3
  • Runtime of Spring app
  • Scheduling
  • Javadoc
  • Files handling

What is cloud?

  • Not only GCloud, AWS, Azure, GeeToo, ..
  • It's about the mindset
  • Something is easier, something is more complex
  • Solves infrastrucure challenges
  • Solves geographical challenges
  • Solves real-time scaling challenges
  • Solves "do not reinvent the wheel" challenges

Deployment model

Delivery model

AWS vs Azure vs GCloud

  • AWS
    • biggest (33 % of the market)
    • largest toolset
    • public cloud based
    • sometimes confusing pricing
  • Azure
    • around 18% market share
    • enterprise customers
    • Working well with other Microsoft technologies
  • Google Cloud
    • youngest and smallest
    • enterprise customers are not priority
    • focus on machine learning, data analysis, cloud deep learning, ..

AWS

  • Many many many many services
  • Process tools
    • Code commit
    • Pipelines
  • Storage tools
    • Databases (SQL/NoSQL)
    • S3
  • Runtime tools
    • EC2
    • EKS
    • Lightsail
    • Lambda
  • Infrastructure 
    • Api Gateway

EC2

  • Amazon Elastic Compute Cloud

  • Has a free tier

  • Provides scalability

  • Nearly 400 instances for virtually every business need

  • Only cloud provider that supports macOS

  • 25 regions and 80 availability zones globally

  • Choice of Intel, AMD, and Arm-based processors

S3

  • Amazon Simple Storage Service

  • Stores files in BUCKETs

  • Fast

  • Scalable

  • https://aws.amazon.com/s3/?nc2=h_ql_prod_fs_s3

Free tier

  • https://aws.amazon.com/free/?nc2=h_ql_pr_ft&all-free-tier.sort-by=item.additionalFields.SortRank&all-free-tier.sort-order=asc&awsf.Free%20Tier%20Types=*all&awsf.Free%20Tier%20Categories=*all

java -jar vs. docker

  • java -jar myapp.jar
    • easiest way
    • must have java on required version installed
    • requires a custom script to start the app automatically
    • path to config can be given by                                     --spring.config.location={path} parameter
  • docker
    • sometimes unavailable
    • everything packed together
    • we need to produce a docker image

Scheduling

  • used for periodical jobs in spring
  • @Scheduled
  • many options how to trigger the job
    • fixedRate
    • cron
    • delay
    • ...

Files in spring

  • most of the time MultipartFile used
    • request can contain multiple files
  • retrieving a file as BYTEARRAY_OUTPUT_STREAM or an actual file type (i. e. application/pdf)
    • often supplied with Content-Disposition header containing filename and the disposition
      • attachment - browser download dialog
      • inline - opens in browser directly

Javadoc

  • The common way to document stuff
  • Used by every library and every company
  • Usually on interfaces and dtos only
  • @param, @return, @see, @link, @deprecated

Q & A