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🍹 Technologies: TypeScript, Node.JS, Express, React, Redux, Next.js, MongoDB, Mongoose, Event Driven, Pub-Sub, Docker, Kubernetes, CI/CD, Skaffold, Apache Kafka, NATS Streaming Server etc.

Aditya Hajare (Linkedin).

WIP (Work In Progress)!

Open-sourced software licensed under theMIT license.

+ Why Database Per-Service

• We want each service to run independently of other services.
• Database schema/structure might change unexpectedly.
• Some services might function efficiently with different types of DB's (SQL vs. NoSQL).

+ Communication Strategies Between Services

• Sync: Services communicate with each other using direct requests.
  • Conceptually easy to understand.
  • Service won't need a database.
  • Introduces a dependency between services.
  • If any inter-service request failes, the entire service fails.
  • The entire request is only as fast as the slowest request.
  • Can easily introduce webs of requests.
• Async (Event Based Communication): Services communicate with each other usingevents.
  • No inter-service dependency.
  • Service will be extremely fast since it has it's own data store.
  • Introduces data duplication. Paying for extra storage + extra DB.
  • Harder to understand.

+ Event Bus

• Many different implementations. For e.g.RabbitMQ,Kafka,NATS etc..
• Receives events, publishes them to listeners.
• Many different subtle features that make async communication way easier or way harder.

+ Kubernetes Basic Terminologies

• Cluster: A collection ofnodes + amaster to manage them.
• Node: Avirtual machine that runs ourcontainers.
• Pod: More or less a running container. Technically, apod can run multiple containers.
• Deployment: Monitors aset of pods. Make sure they are running and restarts them if they crash.
• Service: Provides aneasy-to-remember URL to access a runningcontainer.

+ Kubernetes Config Files

• Tells Kubernetes about the different Deployments, Pods and Services (Referred to asObjects) that we want to create.
• Written inYAML syntax.
• Always store these files with our project source code - they are documentation!
• We can createObjects without config files -DO NOT DO THIS!. Config files provide a precise definition of what our cluster is running.

+ Securely Create Secrets In Kubernetes

• Following command will create a secret calledJWT_KEY:

kubectl create secret generic jwt-secret --from-literal=JWT_KEY=adityahajare