Asp.Net Core 3.1 2020 Conference Notes

Focusing on MicroServices

Subscriber and Publisher (Message Broker)

1. Long-Running Work should not be done on a Socket, it should be done in a queue with Rabit MQ or Active MQ any other queuing technology.
2. The queue application makes sure that the queue message is distributed to only one subscriber as needed at a time. You can have real load balancing and Auto Scaling.
3. Brokers allow subscribing and publishing possible in Queuing Application
4. Multiplexing with Exclusive Consume
   - Multiplexing funnels sequence of related messages concurrently through one route
   - Exclusive consumers snap to sequences and the queue guarantees consistent routing of the message to the same consumer.
   - Often used with scenarios where huge numbers of contexts must be handled, e.g. in workflow processing.
5. Stateful Processing
   - Stateful processing is simplified by pulling a stream stepwise towards a state aggregator (like calculating a rolling average)
   - Consumption can be easily suspended, the state moved, and consumption resumed elsewhere when needed.
6. Sparse Connectivity
   - Sparse connectivity is common with the wireless application, including IoT edge applications
   - Mobile users switch networks, go out of range, hit bandwidth caps, etc.
   - Mobile applications get frequently suspended.
   - You can make communication paths more robust by making them strictly async and using a local store/forward queue setup.
   
   Message Broker Protocols
7. Protocols
   - Protocols we prefer must be vender-neutral, have a formal definition independent of any implementation, and must be under neutral governance.
   - We prefer formal standardization venues such that standards can be composed and be the basis of formal certification programs: W3C, OASIS, IETF, ISO, IEC.
   - Multiple, competing implementations of the full protocol feature range must exist, not just clients.
   - Protocols must be secure, integrate with federated authorization models, and be compatible with common enterprise network policy practices.
   - Protocols must fit the target scenario and not require product-specific extensions for the scenario to work. Still, they must be extensible to allow for backward-compatible evolution in the context of standards collaboration.
   
   Protocol We Prefer
8. Protocols We Prefer
   - IETF HTTPS & WebSocket Protocol
         - Request-response application protocol
         - Azure Services: Azure Event Hubs, Azure Service Bus, Azure Event Grid, Azure Relay, Azure IoT Hub.
   - OASIS AMQP 1.0
          - Vendor-independent and product-independent, symmetric, reliable message transfer protocol with support for multiplexing and flow control.
           - Azure Services: Azure event Hubs, Azure Service Bus, Azure IoT Hub
            - OSS: Apache ActiveMQ Classic, Apache ActiveMQ Artemis, Apache Qpid Broker-J, Apache Qpid C++, Apache Qpid Dispatch Router, Apache Camel, CNCF Strimzi Bridge, Eclipse Hono, Eclipse Ditto, Pivotal RabbitMQ.
   - OASIS MQTT 3.x/5.x
           - Vendor-independent and product-independent, a reliable publish-subscribe protocol for telemetry transfer and state synchronization.
            - OSS: Apache ActiveMQ Classic, Apache ActiveMQ Artemis, Eclipse Hono, Pivotal RabbitMQ, Eclipse Mosquitto, HiveMQ, VerneMQ, etc.
   - CNCF CloudEvents
       - Vendor-independent and product-independent event data model with multiple bindings to protocols and encodings
       - Azure Service: Azure Events Grid, Azure Service Bus and Event Hubs via AMQP
   
   Entity Framework
9. If you want Entity Framework to know of the primary key on the table, then do 
   

   Designing an Agregate and Utilizing Mapping.
   
   modelEntity.Entity<YourModelClass>().HasKey("Id");
   //This let Entity Framwork use that column as an Index, helps in retrieving the data and inserting the data.
   //Another good practice is to encopsulate certain properties that you don't want other class to access.
   
   //If you have a private field Property in your Model Class, you can late Entity Framework know about that field property by explicitly including it  HasField("_nameOfField")
   modelEntity.Entity<YourModelName>().Property(b => b.TeamName).HasField("_YourPrivateField"); This way even when your Field Property is private EFCore can still utilize it.?

    

   
   
   Container Orchestrations Best Practices
10. Tip: Ask yourself as you're making Microservices, does this add value or create unnecessary complexity?
    
    Kubernetes Best Practices
11. Build small containers
    - Multistage builds
12. Application architecture
    - Use Namespaces
    - Helm charts
    -RBAC
13. Implement health Checks
    - Liveness / Readiness Probes
14. Set requests and limits
15. Be mindful of your services
    - Map external services
    - Don't rely on load balancers (Use proxies, load balances are expensive)
    
    API Communication in Microservices
16. 
    Monoliths with .NET 5 and Kubernetes
17. If one microservice gets broken into, build security around that service.
    Building and Debugging Microservices with Kubernetes and Visual Studio
18.