Akka (1): Basic Introduction

Before we touch Akka, we should know what is Akka. Akka uses Actor model to provide a platform to build a correct concurrent and scalable applications. Here we notice two key words, one is concurrent, the other is scalable. (Here I haven’t think out a good example to explain it…

HBase (1): OpenTSDB Table Design

Why we need to learn OpenTSDB? Is it good study case for us to know how to design HBase Table? For me, I would totally say yes. There are many good optimizations which already are applied to OpenTSDB, this open source project. So this post will only say how does OpenTSDB…

Scala (17): JDBC connection pool with Hive

JDBC means Java Database Connection. So when we need to read data from database, we use JDBC to get connection between application layer and database layer. In fact, we can directly connect with database by JDBC, why we need to use connection pool. The…

Scala (15): Regular Expressions

In Scala, it supports regular expressions and provides API to implement it. Here we give example to show them one by one.

findFirstIn

import scala.util.matching.Regex
val pattern = "Scala".r // <=> val pattern = new…

Scala (5): Currying Function

Currying Function is to allow others apply some parameters to your function. In some scenario, some people can apply some arguments to the function and others do rest later. In this case, we can use currying functions.

// normal function:
def…

Scala (2): Factory Pattern

Vehicle Interface:

trait Vehicle {
  def drive
}

Various implement of Vehicle:

class Car extends Vehicle {
     override def drive {
       println("car comming")
     }
  }

Scala (7): constructors, class and trait

Constructor

Constructor is not a special method, which we can use to initialize internal status. So constructor’s concept is very board in Scala. Primary constructors in Scala is the class’s body and it’s parameter list comes…

Nginx Configuration for HTTPS

Before we enter into how to configure Nginx for HTTPS, we need to know why we need HTTPS. We already have HTTP, which is an internet protocol for transferring web content including images, css, js, etc. But it is not safe because web context can be modified or stoled. In this…

MySQL(1)- Index Optimization

• Table Schema

This is table condition. There are five fields.

My command is here to add new data.

MonthlyMovie.objects.filter(MovieID=movieid, Time=itime).update(Count=clicktime)

Functional Programming Principles in Scala (1)

This is online course, named functional programming principles in Scala. I use this course to practice my Scala programming. So here I do summary of my solutions according to its assignments online. Please I don’t follow its restriction, I only…