Rounak Datta rounakdatta

tmux cheat sheet

(C-x means ctrl+x, M-x means alt+x)

Prefix key

The default prefix is C-b. If you (or your muscle memory) prefer C-a, you need to add this to ~/.tmux.conf:

remap prefix to Control + a

Common Options

-#, --progress-bar Make curl display a simple progress bar instead of the more informational standard meter.

-b, --cookie <name=data> Supply cookie with request. If no =, then specifies the cookie file to use (see -c).

-c, --cookie-jar <file name> File to save response cookies to.

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

Hive is an open-source data warehousing solution built on top of Hadoop. It supports an SQL-like query language called HiveQL. These queries are compiled into MapReduce jobs that are executed on Hadoop. While Hive uses Hadoop for execution of queries, it reduces the effort that goes into writing and maintaining MapReduce jobs.

Data Model

Hive supports database concepts like tables, columns, rows and partitions. Both primitive (integer, float, string) and complex data-types(map, list, struct) are supported. Moreover, these types can be composed to support structures of arbitrary complexity. The tables are serialized/deserialized using default serializers/deserializer. Any new data format and type can be supported by implementing SerDe and ObjectInspector java interface.

Query Language

Hive query language (HiveQL) consists of a subset of SQL along with some extensions. The language is very SQL-like and supports features like subqueries, joins, car

Amazon Web Services (AWS) & Google Cloud Platform (GCP) explained in simple English

This guide is only representative from my point of view and it may not be accurate and you should go on the official AWS & GCP websites for accurate and detailed information. It's initially inspired by AWS in simple English and GCP for AWS professionals. The idea is to compare both services, give simple one-line explanation and examples with other software that might have similiar capabilities. Comment below for suggestions.

Category	Service	AWS	GCP	Description	It's like
Compute	IaaS	Amazon Elastic Compute Cloud (EC2)	Google Compute Engine	Type-1 virtual servers	VMware ESXi, Citrix XenServer
	PaaS	AWS Elastic Beanstalk	Google App Engine	Running your app on a platform

Description

[Server] GStreamer ---> HTML [Client]

Require

gstreamer-1.x
Browser which supports video tag of HTML5

debian

Using Git to Manage a Live Web Site

Overview

As a freelancer, I build a lot of web sites. That's a lot of code changes to track. Thankfully, a Git-enabled workflow with proper branching makes short work of project tracking. I can easily see development features in branches as well as a snapshot of the sites' production code. A nice addition to that workflow is that ability to use Git to push updates to any of the various sites I work on while committing changes.

	import java.util

	import org.apache.kafka.clients.consumer.KafkaConsumer

	import scala.collection.JavaConverters._

	object ConsumerExample extends App {

	import java.util.Properties

	package com.example.basic

	import java.util.Properties
	import org.apache.kafka.clients.producer.{Callback, RecordMetadata, ProducerRecord, KafkaProducer}

	import scala.concurrent.Promise


	case class BasicProducer(topic: String, brokerList:String, sync: Boolean) {
	val kafkaProps = new Properties()

	// source: http://stackoverflow.com/a/11058858
	function ab2str(buf) {
	return String.fromCharCode.apply(null, new Uint16Array(buf));
	}