SEARCH KEYWORD -- Hadoop.Linux


  Something you may not know about Shell

Shell is also called command line interface, it is the interface between *nix users and computer. Shell is a program which provides service to access OS kernel services. This article is to introduce some not so well known but useful and interesting knowledge about shell. Wiki shell was born almost at the same time as Unix. The first UNIX shell was written by Ken Thompson in 1971 and its name is Thompson sh. It's older than Linux kernel. The default Shell in most *nix and MacOS is bash, bash was...

   Linux, Unix,Shell,Command     2012-11-24 07:19:47

  How does computer boot up?

The whole boot process of computer can be summarized in 4 phases. 1. BIOS In the 70's  read-only memory(ROM) was invented. The boot program is written into ROM, the first thing the computer does is to read and execute this program when it's powered on. The program in this chip is called "Basic Input/Output System" (BIOS). 1.1 Power-On Self-Test The BIOS will first check whether the computer hardware can fulfill the basic conditions for booting up, this process is called Power-On Self-Test...

   Computer, boot, partition     2013-02-23 23:19:47

  Big file transfer in Linux

It's very common that we need to transfer files between two different hosts such as backups. It is also an very simple task, we can use scp or rsync to complete the task well. But what if the file is very big, it may take some time to transfer it. How can we transfer a big file with high speed? Here we propose one solution. Copy file If we copy one uncompressed file, then we should follow below steps: Compress data Send it to another host Uncompress the data Verify the data integrity This will...

   Linux, SCP,ZIP     2013-01-10 05:55:50

  Twitter to sponsor Apache Software Foundation

Twitter recently made a commitment that they would sponsor the Apache Software Foundation, it will become its official sponsor. The Apache Software Foundation is a nonprofit organization, it can provide the organization and management, legal and financial support for open source projects. As we all know, Twitter loves open source, and its engineers are often engaged in open source community to provide technical support. Twitter team is also responsible for the related construction of the o...

   Apache,ASF,Twitter,Sponsor     2012-04-20 12:08:06

  Oracle released an urgent Java patch

On March 23, Oracle just released an urgent Java patch which is out of its normal update schedule. The security vulnerability is related to the Java SE running in web browsers on desktops. The CVE ID for this issue is CVE-2016-0636. With the unpatched Java, attackers can remotely exploit the target system without username and credentials. Successful exploits can impact the availability, integrity, and confidentiality of the user's system. When the user access pages containing malicious code...

   JAVA,SECURITY,ORACLE,NEWS     2016-03-25 08:39:59

  Video website in big data era

Big data initially means the large data set which is not able to be analyzed, but later it was derivatized to the method to analyze huge amounts of data in  order to gain great value.This is a form which gradually gets attention, It's difficult to analyze these data and it's also difficult to store these data and it needs some unprecedented way, Now in China many companies use the open source Hadoop distributed data cluster to meet the needs of data statistics. Since we can get segmented d...

   Netflix,Big data,Data mining     2013-04-11 04:20:40

  An experience of fixing a memory-corruption bug

During the last 4 months, I was disturbed by a memory-corruption bug, and this bug will cause program crash. Until last Monday, I found the root cause and fixed it. This debug process is a difficult but memorable experience, so I will share it in this article.   My program works as a SMS Hub. When it receives a SMS, it will allocate a structure in heap memory like this: typedef struct { ...... int *a[8]; ...... } info; After processing the SMS, the program will free the m...

   c, debug, unix, solaris, multi-thread     2014-05-04 03:52:43

  Learning Python as your first programming language

Python is a widely used general-purpose, high-level programming language Its design philosophy emphasizes code readability, and its syntax allows programmers to express concepts in fewer lines of code than would be possible in languages such as C. Python now becomes more and more popular and is now being used the first teaching language in some universities. Why would you like to learn Python as your first programming language? Below are the reasons. Python is a high-level language with dynami...

   Python,Advantage     2014-04-07 05:36:04

  Additional steps need to implement to setup shadow-boxV2 OPTEE on Raspberry PI

We followed the Shadow-box v2 project from the https://github.com/kkamagui/shadow-box-for-arm to set up the trustZone on Raspberry PI modeB to protect the Linux Kernel. But got a problem when doing the step: [3.6.5. Activate Shadow-Box for ARM and Start Secure Pi!] to create the hash for the memory area. The result is not shown. If you met the same problem, this is what I did to fix the problem on my PI: 1.1  When we do the step [3.5.1. Copy OP-TEE OS with Shadow-Box for ARM and N...

   HARDWARE,RASPBERRY PI     2019-05-20 08:52:55

  A guide on installing and setting up GitLab server on Ubuntu

GitHub, GitLab and BitBucket are the three most famous code hosting platform in the world. They have different features which allow teams or individuals to share code with others remotely. In case you want to build your own code hosting server so that you can host and share the code by yourself, you can install and set up your own server. In this post, we will walk you through a guide on installing and setting up GitLab server on Linux environment. gitlab is a web based code hosting tool which i...

   UBUNTU,TUTORIAL,GITLAB     2020-04-25 07:05:33

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