SEARCH KEYWORD -- SYSTEM DESIGN


  HeartBleed: Inside the heart, what causes the bleeding?

Just after a few weeks since Apple's famous goto fail bug, there is one bug in OpenSSL which catches the attention from the world again. The bug is named HeartBleed, found in OpenSSL library, a famous open source library supporting lots of  SSL/TLS communication among server/client applications. The reason why this bug catches the attentions from the world is it affects almost all sites which are using the affected OpenSSL library, these includes many applications like Nginx server, some v...

   OpenSSL,HeartBleed     2014-04-09 05:47:30

  Java Cipher encryption/decryption example

In Java, Cipher is the API for doing data encryption/decryption. Many cryptographic algorithms such as AES, DES, RC4 etc can be specified when creating Cipher instance. The Cipher instance calls the underlying algorithm specific implementation to do the actual encryption/decryption.  Before doing the encryption/decryption, a key needs to be created and it will be used to do the encryption/decryption. A sample program for performing all these is : import java.security.Key; import javax.cryp...

   Java, Java Security, Cipher, Example, Sample     2015-08-14 07:07:10

  Mock Solutions for GoLang Unit Test

In Go development, Unit Test is inevitable. And it is essential to use Mock when writing Unit Tests. Mock can help test isolate the business logic it depends on, enabling it to compile, link, and run independently. Mock needs Stub. Stub function replaces the real business logic function, returns the required result, and assists the test. I involved the related test code for Controllers while writing Kubernetes Operator recently, and there would be mocks for GRPC and HT...

   UNIT TEST,TESTIFY,GOSTUB,GOMOCK     2020-10-31 21:59:15

  Understand diff in Unix

diff is an important tool program in Unix. It is used to compare differences of two files, it is the foundation for code version control. If you type : $ diff <file_before_change> <file_after_change> diff will tell you what's the difference between these two files. The result may not be so easy to understand, so now I will show you how to understand diff. 1. 3 formats of diff diff has 3 formats due to historic reasons. normal diff context diff unified diff 2. Demo files For easy d...

   diff,Unix,version control,git     2012-09-03 10:49:36

  How to be an excellent programmer

To use a programming language is very easy for a programmer, but it's a dream for many programmers to be an expert software developer. There are five levels of programmers: Novice, Senior novice, competent, proficient, and expert. Most programmers are senior novice. And programmer living in this level are a lot of people who have 1 to 10 years work experience.As a programmer, how to find the bottlenecks for your improvement and how to improve yourself quickly? This is really not an easy question...

   Programming,Tips,Habit     2013-03-26 09:53:38

  How to commit code to OpenStack

If you want to make contributions to OpenStack, the best way to start is to help the community with blueprint or submit bug fix. To commit codes, you need to conform to some rules in the community. Work flow Register an OpenID Apply for a CLA certificate Apply for company CLA certificate Update contributor list Join OpenStack Contributors group and OpenStack group Set up SSH Keys Get a blueprint/bug git clone codes to local disk. Configure user name and user email and openid Modify codes in a l...

   OpenStack,Contribution     2013-08-04 23:04:45

  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

  Telecom elements in WeChat

As an engineer who spends much time on focusing on WeChat like applications(Skype, Fring, Viber, Kik Messenger, WhatsApp, Talkbox, LINE, Kakao Talk) , I would like to share with you the telecom element in WeChat to show the inheritance and integration of traditional telecom services in the Internet service and applications.First, WeChat is an application to send messages, the fully IP-based messaging capabilities may replace the traditional telecom services such as SMS, MMS and VMS ,This is ver...

   WeChat,Telecom operator     2013-04-13 20:29:46

  Problem and Solution for Installing wxPython on Ubuntu 20.04

When we try to install wxPython lib on Ubuntu system to do software GUI development, most of time we may meet some installation and lib dependency problems. For the latest Ubuntu version, the problems still happen. Below are some common problems which happened frequently and their solution: --------------------------------------------------------------------------------------------------------------- Problem [1]: Install wxPython on Ubuntu 20.04 fail because of dependency package Gtk is not in...

   PYTHON,WXPYTHON,UBUNTU 20.04     2020-09-09 05:32:35

  Taking Precautions to Avoid Shady VPN Providers

VPNs or virtual private networks are virtual tunnels that obscure your IP address, routing your internet traffic through a server located in a country of your choice, in an encrypted and anonymous way. Using a VPN allows you to: secure your sensitive data from hackers obscure the IP address so you can see content not available in your country avoid websites you routinely surf (e.g., Facebook) noticing a different IP address when you are traveling, and asking you to verify your identity bypass t...

   VPN,NETWORKING     2019-02-19 07:26:26

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