Flowchart of how slack decides to ship a notification (Episode 3)

On this publication, we’ll speak concerning the following:

• Flowchart of how slack decides to ship a notification

• Orchestration and choreography

• Find out how to design safe net API entry in your web site?

• How does Amazon construct and function software program?

Flowchart of how slack decides to ship a notification

It’s a nice instance of why a easy characteristic might take for much longer to develop than many individuals assume.

When now we have an excellent design, customers might not discover the complexity as a result of it feels just like the characteristic simply working as supposed.

What’s your takeaway from this diagram?

Picture supply: Slack Eng weblog

How do microservices collaborate and work together with one another?

There are two methods: orchestration and choreography

The diagram beneath illustrates the collaboration of microservices.

Choreography is like having a choreographer set all the principles. Then the dancers on stage (the microservices) work together based on them. Service choreography describes this alternate of messages and the principles by which the microservices work together.

Orchestration is totally different. The orchestrator acts as a middle of authority. It’s chargeable for invoking and mixing the companies. It describes the interactions between all of the collaborating companies. It is rather like a conductor main the musicians in a musical symphony. The orchestration sample additionally contains the transaction administration amongst totally different companies.

The advantages of orchestration:

1. Reliability – orchestration has built-in transaction administration and error dealing with, whereas choreography is point-to-point communications and the fault tolerance eventualities are far more sophisticated.

2. Scalability – when including a brand new service into orchestration, solely the orchestrator wants to switch the interplay guidelines, whereas in choreography all of the interacting companies have to be modified.

Some limitations of orchestration:

1. Efficiency – all of the companies speak by way of a centralized orchestrator, so latency is increased than it’s with choreography. Additionally, the throughput is certain to the capability of the orchestrator.

2. Single level of failure – if the orchestrator goes down, no companies can speak to one another. To mitigate this, the orchestrator have to be extremely obtainable.

Actual-world use case: Netflix Conductor is a microservice orchestrator and you’ll learn extra particulars on the orchestrator design.

Query – Have you ever used orchestrator merchandise in manufacturing? What are their execs & cons?

Find out how to design safe net API entry in your web site?

Once we open net API entry to customers, we want to ensure every API name is authenticated. This implies the consumer have to be who they declare to be.

On this put up, we discover two widespread methods:

1. Token based mostly authentication

2. HMAC (Hash-based Message Authentication Code) authentication

The diagram beneath illustrates how they work.

Token based mostly

Step 1 – the consumer enters their password into the consumer, and the consumer sends the password to the Authentication Server.

Step 2 – the Authentication Server authenticates the credentials and generates a token with an expiry time.

Steps 3 and 4 – now the consumer can ship requests to entry server sources with the token within the HTTP header. This entry is legitimate till the token expires.

HMAC based mostly

This mechanism generates a Message Authentication Code (signature) by utilizing a hash perform (SHA256 or MD5).

Steps 1 and a couple of – the server generates two keys, one is Public APP ID (public key) and the opposite one is API Key (non-public key).

Step 3 – we now generate a HMAC signature on the consumer aspect (hmac A). This signature is generated with a set of attributes listed within the diagram.

Step 4 – the consumer sends requests to entry server sources with hmac A within the HTTP header.

Step 5 – the server receives the request which accommodates the request information and the authentication header. It extracts the required attributes from the request and makes use of the API key that’s saved on the server aspect to generate a signature (hmac B.)

Steps 6 and seven – the server compares hmac A (generated on the consumer aspect) and hmac B (generated on the server aspect). If they’re matched, the requested useful resource can be returned to the consumer.

Query – How does HMAC authentication guarantee information integrity? Why will we embrace “request timestamp” in HMAC signature technology?

How does Amazon construct and function software program? 

In 2019, Amazon launched The Amazon Builders’ Library. It accommodates architecture-based articles that describe how Amazon architects, releases, and operates expertise. 

As of right now, it printed 26 articles. It took me two weekends to undergo all of the articles. I’ve had nice enjoyable and discovered loads. Listed here are a few of my favorites:

🔹Making retries secure with idempotent APIs

🔹Timeouts, retries, and backoff with jitter

🔹Past 5 9s: Classes from our highest obtainable information planes

🔹Caching challenges and methods

🔹Guaranteeing rollback security throughout deployments

🔹Going sooner with steady supply

🔹Challenges with distributed techniques

🔹Amazon’s method to high-availability deployment