Concept – Lets Code

Orchestrate or Choreograph

December 1, 2020December 1, 2020 ALeave a comment

Orchestration vs Choreography ConcernRemote Procedure Call (RPC)Message PassingInterfaceRPC (HTTP / gRPC)Callee owns the interfaceEvent Queue (Kafka topic)Caller owns the interfaceInterface SemanticsCall-return (pull)Pub-sub (push)ContractJSONProtocol Buffers JSONProtocol BuffersPayloadOrder details (required by FF and/or downstream systems) Order details (required by FF and/or downstream systems) Couplingspace and time (sender needs to be aware of the receiver(s)) Space only (send needs to know the… Continue reading Orchestrate or Choreograph

Zookeeper

July 19, 2020July 19, 2020 A1 Comment

Official Doc Link Medium How Does Zookeeper Servers Remain In sync? Medium Zookeeper is written in Java and it is platform independent. Zookeeper is a high-performance coordination service used by distributed systems. Zookeeper allows distributed systems to coordinate each other through a hierarchical name-space of data registrars. In quorum mode, a group of Zookeeper servers,… Continue reading Zookeeper

DynamoDB

June 30, 2020 A1 Comment

Amazon Official Blog Tables, Items, and Attributes The following are the basic DynamoDB components: Tables – Similar to other database systems, DynamoDB stores data in tables. A table is a collection of data. For example, see the example table called People that you could use to store personal contact information about friends, family, or anyone else of interest. You could… Continue reading DynamoDB

JSON Web Tokens | JWT

June 28, 2020 A1 Comment

Video There are many tokens based authentication available, a JSON web token (JWT) is one of them. OAuth is also another well-known mechanism. A JSON web token (JWT) is an open standard (RFC 7519) that is a compact and self-contained way for securely transmitting information between systems as a JSON object. This information can be… Continue reading JSON Web Tokens | JWT

Probabilistic Data Structures: Bloom filter

June 27, 2020July 12, 2020 A1 Comment

Link A Bloom filter is a space-efficient probabilistic data structure, conceived by Burton Howard Bloom. It is designed to tell you, rapidly and memory-efficiently, whether an element is a member of a set. It allows elements to be added to the set, but they can not be removed. Since it is a probabilistic data structure — it tells us… Continue reading Probabilistic Data Structures: Bloom filter

Why should I use a Reverse Proxy?

February 19, 2020June 27, 2020 A1 Comment

Difference between proxy server and reverse proxy server SO A forward proxy is a proxy configured to handle requests for a group of clients under the local Administrators control to an unknown or arbitrary group of resources that are outside of their control. Usually the word “forward” is dropped and it is referred to simply as… Continue reading Why should I use a Reverse Proxy?

process vs thread

October 22, 2019June 28, 2020 A1 Comment

Link Program A program is a set of instructions and associated data that resides on the disk and is loaded by the operating system to perform some task. An executable file or a python script file are examples of programs. In order to run a program, the operating system's kernel is first asked to create a new… Continue reading process vs thread

Epoch Time

September 18, 2019July 5, 2020 A1 Comment

The Unix epoch (or Unix time or POSIX time or Unix timestamp) is the number of seconds that have elapsed since January 1, 1970 (midnight UTC/GMT), not counting leap seconds (in ISO 8601: 1970-01-01T00:00:00Z). Literally speaking the epoch is Unix time 0 (midnight 1/1/1970), but 'epoch' is often used as a synonym for Unix time. Some systems store epoch dates as a… Continue reading Epoch Time

Interesting Read for Design Interview

July 15, 2019September 22, 2019 ALeave a comment

How to do distributed locking. Link Distributed Coordination With ZooKeeper Part 5: Building a Distributed Lock Link Randomness is hard: learning about the Fisher-Yates shuffle algorithm & random number generation. Link ZooKeeper. Link Microservices - Martin Fowler Blog Transaction Across RESTful services. SO

OOPS Basic

October 5, 2017January 4, 2018 ALeave a comment

The four principles of OOP. 1. Encapsulation 2. Abstraction 3. Inheritance 4. Polymorphism Inheritance is a mechanism of acquiring the features and behaviors of a class by another class. The class whose members are inherited is called the base class, and the class that inherits those members is called the derived class. Inheritance implements… Continue reading OOPS Basic