Microservices and Twitter Finagle

Lots of people talk about microservices with REST and thats makes lots of sense because if we think about SOA and Service Orientation Principles we should have interoperability and Rest is great for that.

Such task can be done be a edge service or proxy or api gateway so you really dont need use REST all the time internally.

There is also 2 other important matters like performance for instance, use can use IPC and its way faster than HTTP calls. Second is do something in a JVM language like scala or java - you have benefits doing that. For instance you endup relying more in your compiler and this makes less tests needed and make ir easier to consume services.


Finagle(https://twitter.github.io/finagle/) is used by twitter so if you should dont have doubts about scalability(https://blog.twitter.com/2011/finagle-a-protocol-agnostic-rpc-system). Finagle is built on top of Netty(https://blog.twitter.com/2014/netty-at-twitter-with-finagle). Using it you will give you lots of benefits. Here are some:
  * Connection Pools with throtling
  * Failure Detecture
  * Load Balancers
  * Back Pressure
  * Statistics, Logs and Reports

Finagle is built in Scala and has a very simple and awesome syntax. Finagle uses Futures to perform work. Futures are useful for this kinda of scenarios:
  * Long Cimputations
  * Network calls
  * Reading from disk

All that comes with best of functional programing thanks to scala :-) So you can do all sorts of Higher Order Function and Function First Compositions with map, fold, filter, flatMap, etc... Feature composition is simple and very powerful - I'm a microservice context you deftly need something to deal with composition-calls. You can learn more checking this out(http://monkey.org/~marius/talks/twittersystems/#1).

Finagle has 3 basic ideas: Server, Clients and Proxys. Server can be HTTP rest service with business logic exposed. Clients are libraries that we use the call the Server and proxys are used for all sorts of things - they can act as edge services. Doing all sort of cross cutting concers like: Logging, Security, API Gateway, Redirects, Canary Releases and much more.

Server


The server just have a aplly function and as you can see is very simple and yes there is a Future.

Client


This client code is easy as the Server - Yes Future again - so easy :-)

Proxy


Thats one of the most simple proxys i ever saw.

You can checkout the complete code on my github https://github.com/diegopacheco/Diego-Pacheco-Sandbox/tree/master/scripts/scala/twitter-finagle-playground-fun

Cheers,
Diego Pacheco

Popular posts from this blog

Kafka Streams with Java 15

Image
Kafka Streams is a Streaming library similar to Spark and Flink which works with Apache Kafka. Kafka stream can be useful to process historical and near-real-time big data workloads but also for non-realtime analytical computations at scale for the online world as well. Kafka-Streams is elastic, highly scalable, fault-tolerant, and fully integrated with Kafka. You can use Kafka Stream with Java, Scala, Kotlin JVM applications and also have exactly-once processing semantics. Kafka-Streams is being used by the New York Times, Pinterest, Line, Trivago, Zalando, and many other companies. Today I want to share a video of Kafka-Streams running with Kafka 2.6 and Java JDK 15. So Let's get started. 
read more »

Rust and Java Interoperability

Image
Rust does not stop for one second to amaze me. It looks like Rust was designed to talk to every other language so easily. No kidding, it's clear way Web Assembly and rust have lots in common. Java is never an easy lang to interop with. Today I will show how easily we can interop Java & Rust. In order to do so, we will need to use the Java and Rust compilers. For Java, we will not require any other lib than the standard JDK. For Rust, we will need to create a lib project in cargo and we will need to use the crate JNI. I love this feature because java does not allow low-level code on the main language. So if we need to do something low level, efficiently Rust is my first choice, not only for safety reasons but because is really fast.  Let's get started.
read more »

HMAC in Java

Image
In 2018 AWS CTO(Vogels) said : "Security is everyone's job". For the last 2 years, there was so many famous and big data leaks and breaks that made that statement be very true more than ever. Security often could mean worst performance and worst user experience so in order to get it right you really need to think about the designs before jumping into to code and consider performance and user experience has main requirements.  I was thinking about writing about how to do HMAC in Java for a while and recently Redis 6.0.0 come out and to my surprise, there was a refactoring on the password part in order to use HMAC.  Security easily could scare engineers often because it is not something well spread yet but I believe this will change soon. It does not matter if you have to deal with PII Data or not, security is super relevant because everybody is running their workloads at the cloud or with IoT and Edge devices which means more distribution, more code, more points of fail
read more »