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  When will resizing be triggered in Java HashMap?

HashMap is one of the most frequently used collection types in Java, it stores key-value pairs. Ideally it expects to use hash table which expects the data access time complexity to be O(1), however, due to hash conflicts, in reality, it uses linked list or red-black tree to store data which makes the worst case time complexity to be O(logn).  Although collections are using data structures like arrays and linked lists, unlike arrays, they will dynamically resize when there is not enough spa...

   JAVA,RESIZE,HASHMAP,THRESHOLD     2020-05-02 20:41:19

  Why accessing Java HashMap may cause infinite loop in concurrent environment

HashMap in Java is frequently used to handle key/value pairs. But it is not a good candidate to be used in concurrent environment where ConcurrentHashMap should be used instead. If used in concurrent environment, it may cause lots of unexpected behavior even including make the program getting into an infinite loop situation. To understand how this can happen, let's first discuss how HaspMap works internally. In this post we will use implementation of HashMap before Java 8 as example, Java 8 prov...

   JAVA,HASHMAP,INFINITE LOOP     2020-03-29 01:47:00

  What is Hystrix and How does Hystrix work

Background In distributed systems, there is one effect where the unavailability of one service or some services will lead to the service unavailability of the whole system, this is called service avalanche effect. A common way to prevent service avalanche is do manual service fallback, in fact Hystrix also provides another option beside this. Definition of Service Avalanche Effect Service avalanche effect is a kind of effect where the service provider fails to provide service which causes t...

   AVALANCHE EFFECT,HYSTRIX,DISTRIBUTED SYSTEM     2019-02-04 06:00:38

  Why cannot compare double values directly for equality?

A question in PHP: Get some value from the database and use floatval() to convert it to floatint point value, then compare it with another value which is also converted to floating point value with floatval(). These two values are the same when using var_dump() to output, the two outputs are float(8.87), they are the same. But when comparing them for equality, the result is weird., they are not equal. Why?To analyze this question, we need to start with PHP data types. PHP uses weak types. In PHP...

   PHP,floating, precision,compare,equality     2012-06-27 09:01:36

  Image lazy loading plugins on Github

Image lazy loading is a concept where images are getting loaded only when needed. It has been adopted in many web applications to reduce usage of bandwidth. When a web page is loaded in a web browser, not all the page elements would be visible in the view port, hence those resources(images, videos etc) don't need to be loaded.  Currently there are quite a few open source plugins on Github which can help achieve image lazy loading. Today we will introduce a few of them. Echo.js Echo.js is a ...

   JAVASCRIPT,OPEN SOURCE,WEB DEVELOPMENT,IMAGE LOADING     2017-04-22 01:16:04

  Python Process Protection Watchdog

Project Design Purpose: During participating the cyber exercise as red team member, we found that the injected malware or attack launching program can easy be stopped by the blue team or defense program / mechanisms via killing the process / deleting the file. To address this, our project aims to develop a robust watchdog program designed to bind to target programs, diligently monitor their execution states, and ensure uninterrupted functionality. Continuous Monitoring: Establish a vigilant wa...

       2024-09-14 11:09:14

  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

  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

  The Future of AI Chips Might Not Be GPU

In the layout of AI computing architectures, the model of CPUs working in collaboration with accelerator chips has become a typical AI deployment solution. CPUs act as providers of basic computing power, while accelerator chips are responsible for enhancing computational performance, aiding in the efficient execution of algorithms. Common AI accelerator chips can be categorized into three main types based on their technological paths: GPU, FPGA, and ASIC. In this competition, GPUs have emerged a...

   MICROSOFT,ARM,INTEL,NVIDIA,GPU,OPENAI,CUDA     2024-06-21 22:43:00