SEARCH KEYWORD -- Hadoop.Linux


  When no need 3 handshakes in TCP?

Overview In the previous article titled Why TCP needs 3 handshakes simple answers were provided to the following three questions: Can application data be carried during the first handshake? Can application data be carried during the second handshake? Can application data be carried during the third handshake? Briefly, traditional TCP requires a three-way handshake to establish a connection, and during these three handshakes, only simple SYN and ACK packets are sent. From the perspective o...

   REASON,NETWORK,TCP,EXPLANATION     2024-09-29 03:19:35

  Difference between localhost and 127.0.0.1

Lots of people would think what the address 127.0.0.1 is when first seeing this address. In fact, 127.0.0.1 is a loopback address which refers to the local machine. It is generally used for local testing. When typing ping 127.0.0.1 on local command console, it will send network packets to local IP/TCP layer to test whether IP/TCP works properly or not.  To those who are used to use localhost, it is actually mapped to 127.0.0.1 by default. There are hosts files in the system which store this...

   LINUX,NETWORK,LOCALHOST,127.0.0.1,LOCALHOST VS 127.0.0.1     2018-09-29 22:11:12

  Shell script common interview questions

Shell script is frequently used when monitoring system status on Linux. It's not an easy task to write shell script but it's a very important skill for developers and system administrators to ease work and automate common tasks. This post will share some common interview questions about shell script. 1. Get random characters(8 characters) Method 1 # echo $RANDOM |md5sum |cut -c 1-8 471b94f2 Method 2 # openssl rand -base64 4 vg3BEg== Method 3 # cat /proc/sys/kernel/random/uuid |cut -c 1-8 ed...

   LINUX,INTERVIEW,SHELL SCRIPT     2018-09-28 10:46:00

  Latest : Asp.Net 5 Beta 7 Is Now Available

Asp.net developers can now use the latest update asp.net 5 Beta 7 on both NuGet and Visual Studio 2015 to make good asp.net development practices. The update also has the first public preview of .Net Execution Environment for Linux and Mac without any need of Mono. To know how to use asp.net 5 beta 7, read this article further. You need to install the update first to use its features with Visual Studio 2015. You can download and install it from Microsoft’s official site. The update brings ...

   ASP.NET 5 BETA 7     2015-09-18 06:33:54

  The story behind Sublime Text

Sublime Text is a cross-platform text and source code editor, with a Python application programming interface (API). The graphical user interface design was inspired by Vim.Its functionality is also extendable with plugins; Post its release, it gained much attention and wide popularity. Do you know what's the story behind Sublime Text? Jon Skinner left his job as a software engineer at Google in order to pursue a dream: to build a better text editor. The end result is the popular Sublime Text t...

   Sublime Text,Story,History     2013-09-22 11:05:36

  Using Fabric to deploy web app

Many people may use FTP and rsync to synchronize codes to server, this way is fine but it may be troublesome when you need to deploy many times a day, actually there is a simple way if you can spend time on finding the fast way. We introduce Fabric today for deploying web app to remote server. Fabric is a deployment tool written with Python, the biggest feature if it is you no need to login to remote server, you can execute remote commands locally. Here is s simple deployment script written with...

   Fabric, Web deployment,SSH,Python     2012-12-08 03:16:00

  What is goroutine?

Casual Talk Golang is quite enjoyable to write, aside from the tedious if err != nil checks. One of the fundamental reasons for the joy is goroutine, a core feature of Golang. Understanding goroutines in detail is worthwhile, as they contribute significantly to the pleasure of working with Golang. So, let's talk about goroutines, hoping to provide some insights to the readers. TL;DR: We'll start by talking about assembling a computer, then delve into some concepts of the operating system, such ...

   EXPLANATION,GOLANG,GOROUTINE     2024-01-21 03:26:10

  How to prevent next HeartBleed bug?

How to ensure the security of open source projects is a concern for many open source users including individual users and companies. But it's not an easy task to ensure the security of open source projects. Because everyone can see the source code, there is much higher possibility that a bug may be found by someone. Once a bug is disclosed, people may exploit it and do evil things, this may cause loss of money either for individuals or companies, some of the bugs may even have big impact to the...

   Open source,HeartBleed,Security     2014-04-24 09:07:05

  System programming is still there

System programming is the practice of writing system software. System software lives at a low level, interfacing directly with the kernel and core system libraries. Your shell and your text editor, your compiler and your debugger, your core utilities and system daemons are all system software. But so are the network server, the web server, and the database. These components are entirely system software, primarily if not exclusively interfacing with the kernel and the C library. But nowadays more...

   System programming     2014-02-27 05:46:48

  How does GoLang know how many CPUs to use?

When running lscpu command on Linux, it will list the CPU info on the machine. Take one example where there is one CPU with 2 cores and each core has two threads which indicates there are 4 cores available. Now let's see how many cores GoLang program would identify. From output, NumCPU and GOMAXPROCS both output 4 which is expected. How does go runtime get this info, does it get it through similar command like lscpu or /proc/cpuinfo? Let's dig more in GoLang's source code. In runtim...

   GOLANG,CPU,NCPU     2020-12-29 23:22:15

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