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  Deep Understanding of ReentrantLock: Unlocking the Mysteries of Java Concurrent Programming

ReentrantLock introduction ReentrantLock is a class in the Java concurrent package, java.util.concurrent.locks, and is an implementation of the Lock interface. As its name suggests, it is a reentrant mutual exclusion lock. A mutual exclusion lock is a synchronization tool used to protect shared resources, ensuring that only one thread can access the resource at a given time. Reentrant means that a thread can acquire the same lock multiple times without causing a deadlock. This lock provides some...

   JAVA,REENTRANTLOCK,CONCURRENCY,MULTITHREADING     2023-05-22 08:01:13

  Python PLC Honeypot: Env Deployment And Attack Detection

In the previous article, we introduced the design of Python PLC Honeypot Project, this article will provide detailed step-by-step instructions on how to deploy and use the honeypot system in your environment for detecting potential attacks on OT (Operational Technology) networks. The article includes three main section:   Design of Attack Alert and Notification Function Honeypot deployment: an example deployment of a mixed OT protocol honeypot, consisting of a simple setup with...

       2024-12-01 00:27:33

  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

  Top 10 Go Coding Traps and Tips

Go is currently the most common programming language in cloud development. Though I use it very much in my work, I am still repeating certain mistakes. This article is more a record of these errors, figuring out the causes and solutions so that people who read this article will save themselves time when coming across the same problems. Let’s cut through to the tips. Don’t rely on index var in the for loop The most common mistake we make is that we often create goroutine&nbs...

   TIPS,GOLANG,NIL INTERFACE     2021-07-03 23:45:51

  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

  Set Real-Time Clock Unit for OT/IoT Device

Configure DS1307 RTC on BeagleBone-Black Arduino or Raspberry-PI Figure-00: Project Overview Diagram , version v0.1.2 (2024) Program Design Purpose: Real-Time Clock (RTC) modules are essential for maintaining accurate timekeeping in various applications, including system clocks, data logging, and alarm systems. In scenarios where devices operate offline, such as a ship's NMEA 0183 data recorder that logs engine and rudder data, or an RTU (Remote Terminal Unit) with real time state change config...

       2024-08-18 03:09:06

  Python FTP Server and Client

Distributed Log File Automated Archive System This week, we will introduce the automated compute cluster nodes' log automated archive system project and FTP Communication utility library module. Program Design Purpose: This project aims to create an FTP server & client lib program for file transfer and a files management system for log data synchronization. We will develop an automated log file archive system that regularly collects newly generated log files from multiple nodes in a compute...

       2024-09-29 04:07:50

  SIEM Big Data Visualization [04] : Data Transmission Latency SIEM Log Analysis Dashboard

This article will introduce the Data Transmission Latency Log Analysis Dashboard developed for SIEM big data analytics. This is part of the SIEM big data visualization project, if you are interested about other dashboard plug in, you can check below links: SIEM Big Data Visualization [01] : Dashboard for Monitoring Scam Events in Critical Infrastructure SIEM Big Data Visualization [02] : Dashboard for Summarizing SG National Cyber Threats in Critical Infrastructure SIEM Big Data Visualization [...

       2024-11-03 20:49:18

  4 deployment modes of Redis

As a high-performance in-memory database, Redis is widely used in current mainstream distributed architecture systems. To improve system fault tolerance, using multiple instances of Redis is also inevitable, but the complexity is much higher than that of a single instance. This article mainly introduces the four deployment modes of Redis and their advantages and disadvantages. Standalone Standalone mode is to install a Redis, start it, and business connects to it and that's all. The specific ...

   REDIS,STANDALONE,MASTER-SLAVE,SENTINEL,CLUSTER     2023-03-03 21:35:09

  Why (offset, limit) is slow in database select?

Starting from a problem Five years ago when I was working at Tencent, I found that MySQL request speed was very slow in the pagination scenario. With only 100,000 data, a select query on a single machine took about 2-3 seconds. I asked my mentor why, and he asked in return, "In an indexing scenario, what is the time complexity to get the nth largest number in MySQL?" The pursuit of the answer Confirming the scenario Assuming there is an index on the "status" column, a query like "select * from t...

   SLOW,LIMIT,OFFSET,MYSQL     2023-03-12 05:21:02