This was a guest repost by Leandro Moreira.
When we usually is interested about scalability we look for links, explanations, books, and references. This is the mini article links to the references I think might help you in this journey.
DISCLAIMER:
You don ' t need to has N machines to build/test a Cluster/high scalable system, currently can usevagrant and Up N machines easily.
The REFERENCES:
Now so you know you can empower yourself with virtual servers, I Challenge do not only read these links but put them into practice.
- First of all, motivate yourself by watching this tutorial using Nodejs + nginx + applying static caching + load Balancing + testing, all this in 7 minutes.
- Add these words and their meaning to your vocabulary:scalability, failover, single point of failure (SPOF), sharding, rep Lication and load balancing; Even if you don ' t understand them completely.
- In order to has a general overview and the Reasons/whys about scalable systems, I strongly recommend your to read scalable Web Architecture and distributed Systems. This is a great introduction.
- After you get the "general idea" can move on to understand how to use a load balancerand what decisions and problems you Would face. And then your can try to run a haproxy and make it is not a single point of failure too.
- Dare yourself to serve 3 million requests per second if for this task you ll need togenerate 3 million requests, fine Tun E your Web server and finally scale and test it.
- Your application is already scalable, now you need to scale Your databases. They is very important part of your application, where I recommend you to read at least how MongoDB scales with sharding a nd replication and Cassandra with their almost linear scalability and the ease of adding nodes to the cluster.
- Since your application and database is scalable and fault tolerant, it ' s good to save your servers unnecessary workload a ND also make the responses to the user faster. Learn. A good request is the one, that never reached the "real server".
- Let's assume we ' re deploying the whole infrastructure within a single data center and now we have another SPOF. Since all servers is in the same space, some natural disaster might happen or even the simple power outages. Good news is that Cassandra has support to multiple data center out of the box and you can see how Google face this issue . If your user is on Brazil, don ' t make him travel longer than he needs and remember even with the best situation we still H Ave Latency.
Good questions to test your knowledge:
- Why to scale? How people does that usually?
- How to deal with the user session on memory RAM with N servers? How LB know which server are up? How LB knows which server to send the request?
- Isn ' t LB another SPOF? How can we provide a failover for LB?
- Isn ' t my OS limited by 64K ports? is Linux capable of doing that out of the box?
- How do does MONGO solves failover and high scalability? How about Cassandra? How Cassandra does sharding when a new node come to the cluster?
- What is the cache lock? What caching policies should I use?
- How can the a single domain have multiple IP addresses (ex: $ host www.google.com)? What is BGP? How can we use DNS or BGP to serve geographically users?
Bonus Round: Sometimes simple things can achieve your goals of making even an AB test.
Please let me know any mistake, I'll be happy to fix it.
Reference:
Http://highscalability.com/blog/2014/11/24/a-flock-of-tasty-sources-on-how-to-start-learning-high-scala.html
A Flock of Tasty Sources on what to Start learning high Scalability
