Sayed Ahmed

Sayed Ahmed Linkedin: https://ca.linkedin.com/in/sayedjustetc Blog: http://sitestree.com, http://bangla.salearningschool.com Founder & CEO, Justetc (Just Et Cetera) Technologies, Canada

Author's posts

Jul 16

MongoDB Examples – 4 : Reading from MongoDB

//Install express first //npm install express   var express = require(‘express’); var app = express(); const MongoClient = require(‘mongodb’).MongoClient; let db; MongoClient.connect(‘mongodb://localhost/issuetracker’).then(connection => { db = connection; app.listen(3000, () => { console.log(‘App started on port 3000’); }); }).catch(error => { console.log(‘ERROR:’, error); });   app.get(‘/api/issues’, (req, res) => { db.collection(‘issues’).find().toArray().then(issues => { const metadata = …

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Jul 16

MongoDB Examples – 3: NodeJS, MongoDB: CallBacks, Promises, Generators, Async

Create the Script File: nano trymongo.js Put the content ‘use strict’; const MongoClient = require(‘mongodb’); function usage() { console.log(‘Usage:’); console.log(‘node’, __filename, ‘<option>’); console.log(‘Where option is one of:’); console.log(‘ callbacks Use the callbacks paradigm’); console.log(‘ promises Use the Promises paradigm’); console.log(‘ generator Use the Generator paradigm’); console.log(‘ async Use the async module’); } if (process.argv.length < …

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Jul 16

MongoDB Examples – 3: MongoDB Node.js Driver

Install node -> For Mac, to have node, install homebrew first -> then: brew install node, brew update   MongoDB Node.js Driver To Install:  npm install mongodb –save Create a NodeJS Script to interact with MongoDB File Create: nano node.script.js NodeJS code: Put in the file const MongoClient = require(‘mongodb’).MongoClient; MongoClient.connect(‘mongodb://localhost/playground’, function(err, db) { db.collection(’employees’).find().toArray(function(err, …

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Jul 16

MongoDb Examples – 2 : Schema Initialization

Create a Mongo Script and Populate with some data:   Create: nano init.mongo.js  (in Linux or MacOs)   Put content in the script file:   db = new Mongo().getDB(‘issuetracker’); db.issues.remove({}); db.issues.insert([ { status: ‘Open’, owner: ‘Ravan’, created: new Date(‘2016-08-15’), effort: 5, completionDate: undefined, title: ‘Error in console when clicking Add’, }, { status: ‘Assigned’, owner: …

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Jul 16

MongoDB Examples – 1

mongod -> to run the server mongo -> to run Mongo Shell db-> to see current/selected/in-use database name use playground -> create or change database (playground) show databases -> see all databases show collections -> see the collections (employees for example) in current database Insert one Record/data db.employees.insert({name: {first: ‘John’, last: ‘Doe’}, age: 44});   …

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Jul 13

Blockchain, Ethereum, Hyperglobe, Cryptography

Cryptographic Algorithms and Protocols “Often cryptographic algorithms and protocols are necessary to keep a system secure, particularly when communicating through an untrusted network such as the Internet. Where possible, use cryptographic techniques to authenticate information and keep the information private (but don’t assume that simple encryption automatically authenticates as well). Generally you’ll need to use …

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Jul 01

Introduction to Scala : Learning Resources

Creating a Scala Doc

Jul 01

AWS Tools for Big Data

Big Data on AWS Big Data Analytic Frameworks “Build highly scalable and secure Big Data applications fast. No hardware to procure, no infrastructure to maintain.” With AWS big data tools “you can rapidly scale virtually any big data application including data warehousing, clickstream analytics, fraud detection, recommendation engines, event-driven ETL, serverless computing, and internet-of-things processing” …

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Jul 01

Big Data and AWS

AWS Concepts and Tools for Big Data Implementation Amazon Kinesis Big Data Streaming and Amazon Kinesis Example: Using Amazon Kinesis to Stream and Analyze Apache Server Log Data Amazon Athena Big Data Processing and Analytics Example: Using Amazon Athena to Query Log Data From Amazon S3 DynamoDB No SQL DBMS: Storing and Querying Data on …

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Jun 30

Configure Mac OsX for Laravel Development with Valet

/usr/bin/ruby -e “$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)” brew update brew install homebrew/php/php71 composer global require laravel/valet export PATH=$PATH:~/.composer/vendor/bin — not required curl -sS https://getcomposer.org/installer | php curl https://getcomposer.org/installer | php — php -r “copy(‘https://getcomposer.org/installer’, ‘composer-setup.php’);” php -r “if (hash_file(‘SHA384’, ‘composer-setup.php’) === ‘669656bab3166a7aff8a7506b8cb2d1c292f042046c5a994c43155c0be6190fa0355160742ab2e1c88d40d5be660b410’) { echo ‘Installer verified’; } else { echo ‘Installer corrupt’; unlink(‘composer-setup.php’); } echo PHP_EOL;” php …

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Jun 30

Forge: Painless Server Management including Digital Ocean and AWS

PAINLESS SERVER MANAGEMENT. Sure, you can do all of these on your Own in platforms like AWS or Digital Ocean. However, Forge has made them easy and user friendly (you do not have to be an expert on Linux or so) Numerous Cloud Providers Choose between AWS, Digital Ocean, Linode, or even your own custom …

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Jun 30

Envoyer: Zero Downtime PHP application Deployment

Zero Downtime PHP Deployment – Laravel application deployment Deployments you’ve only dreamed about. Zero downtime. Zero fuss. https://laracasts.com/series/envoyer/episodes/1

Jun 23

Ambari Tools for Big Data

HDFS MapReduce2 YARN Hive HBase Pig Sqoop Oozie ZooKeeper Flume Ambari Metrics BigInsights – Big R BigInsights – BigSheets BigInsights – Big SQL BigInsights Data Server Manager Kafka Knox R Slider Solr Spark BigInsights – Text Analytics BigInsights Home

Jun 23

Some More Big Data Terms and Technologies

HDFS: “HDFS is a distributed file system that provides high-performance access to data across Hadoop clusters. Like other Hadoop-related technologies, HDFS has become a key tool for managing pools of big data and supporting big data analytics applications.” http://searchbusinessanalytics.techtarget.com/definition/Hadoop-Distributed-File-System-HDFS   Apache Ambari “A completely open source management platform for provisioning, managing, monitoring and securing Apache …

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Jun 23

Some Big Data Terms

MapReduce ” MapReduce is a programming model and an associated implementation for processing and generating big data sets with a parallel, distributed algorithm on a cluster.[1][2] A MapReduce program is composed of a Map() procedure (method) that performs filtering and sorting (such as sorting students by first name into queues, one queue for each name) …

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Jun 18

Spark and Machine Learning Resources

What is Apache Spark: What is Spark SQL? What is RDD? What is Spark ML? What is GraphX https://en.wikipedia.org/wiki/Apache_Spark (Sure theoreticians matter, SPark was first developed at the University of California, Berkeley’s AMPLab) Tutorial: Apache Spark – RDD https://www.tutorialspoint.com/apache_spark/apache_spark_rdd.htm Hands-on Intro to Machine Learning with Apache Spark and Apache Zeppelin Apache Spark Machine Learning Tutorial …

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Apr 25

Some More PIMs

Solid Commerce: http://www.solidcommerce.com/software/product-tour EcomDash: https://www.ecomdash.com/best-inventory-software-prices/ SalesWarp: https://saleswarp.com/partners/

Mar 30

Amazon AWS Features

Desktop & App Streaming Amazon WorkSpaces: “Amazon WorkSpaces provides users with a desktop experience in the cloud that can be accessed from any connected device. Quick Setup option: Quickly launch WorkSpaces for an individual or small group of cloud-based users in less than 20 minutes.” Reference:  https://console.aws.amazon.com/workspaces/home?region=us-east-1 Amazon AppStream 2.0 is a fully managed, secure …

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Jul 17

SCJP: Java Operators

By Sayed Exams like SCJP test your understanding of Java operators and how to use them like: assignment operators: =, +=, -= arithmetic operators: +, -, *, /, %, ++, — relational operators: <, <=, >, >=, ==, != logical operators: &, |, ^, !, &&, || conditional operators: ? : Also operators to check …

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Jun 05

SCJP: Classpath and Jar

Java certification exams like SCJP test your knowledge about java classpath. Check here for an excellent resource on the topic . System classpath We can specify classpath in the command line or make use of a `system’ class path. The IDEs have their own way of maintaining class paths. System class paths will be used …

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Feb 13

SCJP: Sun Certified Java Programmer: All that you need to know

Introduction to Sun Certified Java Programmer Certification Course Java : SCJP: Important Resources JAVA: Some links: useful for exams like scjp/scja SCJP Essential Knowledge SCJP Practice Exams SCJP Training: Lesson 1: Develop code that declares classes (including abstract and all forms of nested classes), interfaces, and enums, and includes the appropriate use of package and …

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Dec 29

SCJP: Java Operators

Exams like SCJP test your understanding of Java operators and how to use them like: assignment operators: =, +=, -=arithmetic operators: +, -, *, /, %, ++, –relational operators: < , , >=, ==, !=logical operators: &, |, ^, !, &&, ||conditional operators: ? : Also operators to check the equality of two objects or …

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Dec 07

SCJP: Random Stuffs

An enum may NOT be declared in a method An enum can be imported If the JVM has a choice, it will select a method without varargs before selecting a method with varargs When enums are equal, both .equals and == always return true The headMap() method returns the portion of the map whose keys …

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Oct 24

SCJP: Basic Java I/O

ByteStream is the basic I/O stream. Handles data as a stream of bytes. Does operation with byte unit and uses 8 bit. FileInputStream, FileOutputStream – can be used to copy files as byte by byte. Character Streams: FileReader and FileWriter are character streams. They treat file data as 16 bit unicode charater streams. InputStreamReader, OutputStreamWriter …

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Sep 13

SCJP: Class Declarations

class declarations Start with modifiers such as public, private followed by class keyword The class name, with the initial letter capitalized The name of the class’s parent (superclass), preceded by the keyword extends (if any). A class can only extend (subclass) one parent. list of interfaces implemented by the class, preceded by the keyword implements …

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Jul 21

SCJP Training: Lesson 6: Collections / Generics

Object Ordering Object as a Superclass Generic Types Declaring Classes Defining an Interface Passing Information to a Method or Constructor Returning a Value from a Method Generic Types Generic Methods and Constructors Wildcards Algorithms

Jun 10

SCJP Training: Lesson 1: Develop code that declares classes (including abstract and all forms of nested classes), interfaces, and enums, and includes the appropriate use of package and import statements (including static imports).

Declaring Classes Abstract Methods and Classes Nested Classes Interfaces Enum Types Creating and Using Packages Using Package Members (import statements, static imports) Defining an Interface Implementing an Interface Abstract Methods and Classes Primitive Data Types Arrays Enum Types Understanding Instance and Class Members Variables Declaring Member Variables Understanding Instance and Class Members Passing Information to …

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May 02

SCJP Sun Certified Programmer for Java 6 Exam 310-065 ©2008 (Katherine Sierra, Bert Bates)

SCJP Sun Certified Programmer for Java 6 Exam 310-065 ©2008 (Katherine Sierra, Bert Bates): SCJP Sun Certified Programmer for Java 6 Exam 310-065 ©2008 (Katherine Sierra, Bert Bates)

Oct 20

SCJP: Short Notes

For the package package com.sun2;public enum Seasons {SUMMER, FALL, WINTER, SPRING} Valid import statements are: import com.sun2.Seasons; // the class import static com.sun2.Seasons.*; //all enum valuesimport static com.sun2.Seasons.FALL; //only one enum value An interface can extend many interfaces Interfaces can have variables, overrides and overloads An enum can have methods and can override those methods …

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Sep 04

SCJP: Rules

A class’s superclasses don’t have to implement Serializable in order to be serialized if a superclass doesn’t implement Serializable then it’s constructor will run during deserialization A transient variable’s state is lost during serialization, but a volatile variable’s state is not lost Java:Volatile variable Transient Variable NumberFormat, Calendar, DateFormat are abstract classes. Use the getInstance …

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