SEARCH KEYWORD -- JAVA APPLICATION MAINTENANCE


  OT Railway System Development: How to Use PLC to Implement Land Based Railway Track Fixed Block Sign

Figure-00: Railway fixed block signaling system over view diagram, version v1.3 (2024) Project Design Purpose: This project aims to use Programmable Logic Controllers (PLC) with train detection sensors and train control signals to develop an automated OT system for railway track fixed block signaling control. The system will include a digital equivalent simulation to explain the logic of the track fixed block Automatic Train Control (ATC) mechanism for demonstration and training purposes. In th...

       2024-07-27 04:08:41

  Why TCP needs 3 handshakes

Prerequisite Knowledge First, let's look at the control bits and state machine of TCP, which form the basis for understanding the three-way handshake of TCP. TCP Packet Control Bits The control bits in the TCP packet header are used to control the status of the TCP connection and can indicate various control information such as connection establishment, termination, reset, etc. There are six common control bits: SYN (Synchronize Sequence Numbers): Requests to establish a connection (part of the...

   REASON,NETWORK,TCP,EXPLANATION,HANDSHAKE     2024-09-28 08:57:52

  Kubernetes Authentication & Authorization 101

If we want to build a system with user modules, Authentication and Authorization are something that we can never ignore, though they could be fuzzy to understand. Authentication (from Greek: αὐθεντικÏŒς authentikos, “real, genuine”, from αὐθέντης authentes, “author”) is the act of proving an assertion, such as the identity of a computer s...

   RBAC,AUTHORIZATION,AUTHENTICATION,KUBERNETES     2021-06-05 23:19:18

  Sass Style Guide: A Sass Tutorial on How to Write Better CSS Code

Writing consistent and readable CSS that will scale well is a challenging process. Especially when the style sheets are getting larger, more complex, and harder to maintain. One of the tools available to developers to write better CSS are preprocessors. A preprocessor is a program that takes one type of data and converts it to another type of data, and in our case CSS preprocessors are preprocessing languages which are compiled to CSS. There are many CSS preprocessors that front-end develop...

   CSS,SASS,TUTORIAL     2015-09-17 06:40:47

  How to choose a jQuery plug-in?

jQuery plug-in provides a good way to save time and simplify the development, programmers don't need to write each component from scratch. However, the plug-in will also be a destabilizing factor in your code library. A plug-in saves countless development time, but a poor quality plug-in will cost more than the actual time to write your own component from scratch. Luckily, usually you have many pls to choose from, but even if you have only one plug-in, you also need to know whether it's worth us...

   jQuery, plug-in     2012-10-27 03:51:40

  A journey to investigate a goroutine leakage case

In Go, creating goroutines is straightforward, but improper usage may result in a large number of goroutines unable to terminate, leading to resource leakage and memory leaks over time. The key to avoiding goroutine leaks is to manage the lifecycle of goroutines properly. By exporting runtime metrics and utilizing pprof, one can detect and resolve goroutine leakage issues. This post will go through one real case encountered by the author. The author maintains a service that connects to a targe...

   TIMEOUT,SSH,GUIDE,DEBUG,LEAK,GOROUTINE,PPROF,GOLANG     2024-03-16 11:00:23

  What have been Facebook’s greatest technical accomplishments?

To maintain a large website which gets billions of requests er day and keeps very fast response speed is not an easy task. Many big companies are trying best to improve user experience by adopting different techniques. There is a question on Quora which asks "What have been Facebook’s greatest technical accomplishments?". There is a person who worked in Facebook before provided an answer which helps us understanding how Facebook handles huge amount of traffic each day. Here is the answer f...

   Facebook, Design, Efficiency     2013-01-15 07:32:07

  Power Grid OT Simulation System

Mini OT-Energy-System Cyber Security Digital Twin Figure-00: Power_Grid_OT_Simulation_System Environment Diagram, version v0.1.2 (2024) Project Design Purpose: The primary objective of this project is to develop a scaled-down Operational Technology (OT) digital twin/equivalent — an advanced software simulation system capable of emulating the functionality of an small-sized 18KW (560+MkWh/year) hybrid power grid. This system will meet the requirements for cybersecurity training, exercises...

       2024-10-13 09:00:12

  IoT System Cyber Attack Case Study 02: Python Deserialization Attack and Library Hijacking Attack

Project Design Purpose: The objective of this cyber attack case study is to develop a workshop that demonstrates how a red team attacker can permanently compromise a people detection radar IoT device. The attack path is achieved through a series of attacks, including traffic eavesdropping, data deserialization attacks, web shell attacks, remote command/code execution, and Python library hijacking attacks. This case study is intended for IoT and data security professional training, aiming to ill...

       2024-07-14 01:40:09

  Consistency between Redis Cache and SQL Database

Nowadays, Redis has become one of the most popular cache solution in the Internet industry. Although relational database systems (SQL) bring many awesome properties such as ACID, the performance of the database would degrade under high load in order to maintain these properties. In order to fix this problem, many companies & websites have decided to add a cache layer between the application layer (i.e., the backend code which handles the business logic) and the storage layer (i.e., the SQL d...

   REDIS,CACHE,DATABASE     2019-07-07 08:14:16

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