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