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  When and Where to Use Pointers in Go

When declaring variables in Go, we usually have two syntax options: In some scenarios, pointers; in others, reference; sometimes, either. It’s great to have choices, but it is also confusing sometimes as to which one in which scenario. To be more reasonable in choice-making, I started from pointers, walked through their natures, and summarized some rules in using them in Go. from unsplash, Jordan Ladikos Pointers Go has pointers. A pointer holds the memory address of a ...

   POINTER,GOLANG     2022-05-01 02:24:43

  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

  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

  Cloud Computing’s most Basic Concepts-Service Models

With the containerization of Docker, Kubernetes, CNCF, and the development of open-source communities, related frameworks and technology is booming and iterating rapidly. Cloud Computing, been applied for many years, is pushing developers into the new technological era. Companies and developers who are not using or not planning to use Cloud-Native gradually feel tremendous pressure in keeping up with the technology trends. The first step is to understand the concepts of IaaS, PaaS, FaaS, SaaS, S...

   CLOUD,PAAS,IAAS,CONCEPT     2021-01-24 05:23:11

  How Query Optimizer Works in RDBMS

In a previous post, we discussed how the various relational operators are implemented in relational database systems. If you have read that post, you probably still remember that there are a few alternative implementations for every operator. Thus, how should RDBMS determine which algorithm (or implementation) to use? Obviously, to optimize the performance for any query, RDBMS has to select the correct the algorithm based on the query. It would not be desirable to always use the same algori...

   DATABASE,DATABASE DESIGN,DATABASE OPTIMIZATION     2019-04-20 07:26:32

  Go Error Best Practice

Being indulged in Go for quite a while and having implemented web-related programs, grpc interfaces and Operators, I seem to be an advanced beginner now. However, I am still a raw hand in production-environmental debugging, which is cumbersome if done by querying logs or error messages. Imagine the scenario that a full-text search is called when the specific location of the error log is missing. Then what happens when those error logs are not only in one place? Yes, my error logs can no longer h...

   GO ERROR,ERROR HANDLING     2021-10-07 07:38:28

  Python Deserialization Attack Introduction: How to Build a Python Pickle Bomb

This article introduces an old and classic unsecured Python data serialization feature (the pickle library) and demonstrates how a red team attacker can exploit it to create a malicious binary or text data file that executes remote code or commands upon deserialization. The following attack flow diagram illustrates this process: We will follow 3 steps with the program code to show how Deserialization Attacks Work:   [ Step1 ] Crafting Malicious Data: An attacker crafts a malicious payloa...

       2024-07-07 03:08:22

  File upload in PHP

File is a special kind of form data, when being uploaded to the server through HTTP POST request, PHP will create a $_FILES global array, the relevant file information will be stored in this global array. We will illustrate file upload with some code snippets using PHP and look into the internal work mechanism. Lastly will talk about file upload security. File upload In order for users to upload files in client side, we have to provide a form on the user interface. Since the uploaded file is a s...

   File upload,PHP     2012-11-30 22:01:28

  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

  Build a Kubectl Plugin from Scratch

by author The command-line tool kubectl is indispensable when using Kubernetes. You need it to query related Pod and Service information both in developing or performing some maintenance operations, such as events, scale, rolling update, etc. However, when using kubectl, there are many inconveniences. Though Kubernetes is officially maintaining kubectl¹, and you can submit the problems, improvement, and even PR in its Github Issues, you still have to wait long before its release. The m...

   KUBENETES,KUBECTL,PLUGIN,GOLANG     2020-12-02 03:43:16

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