SEARCH KEYWORD -- REASON


  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

  Efficiency of code execution

If you want to optimize your program codes, you need to find their Hotspot, i.e, the codes which are executed most frequently. If you can optimize this portion of codes a bit, you may gain much improvement of your code efficiency. Here I give you three examples about efficiency of code execution.1. PHP's Getter and Setter (From Reddit)This example a quite simple, you can skip it if you want.Consider the code below, we can find it's slower when we use Getter/Setter method to read a member variabl...

   Code, Efficiency,Analysis,Trick     2012-07-13 10:59:21

  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

  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

  Android Security

Android is an open source mobile platform that includes an operating system, middleware and applications. Android has revolutionized the mobile world in a big way. Android, which started as an alternative to Apple’s iOS, is now slowly eating into the market share of Apple and is of primary concern to the company. Let’s have a brief introduction about android and then look into the security concerns and vulnerabilities that need to be focused on. Android Introduction: Android was deve...

   Android security,Input validation     2013-04-16 12:19:37

  Processing Unicode Data in Python - A Primer to Understand Non-English Data Processing

Introduction: Currently we live in a world where people of diverse cultures/backgrounds use electronic devices to express their ideas, do their daily work that earns them their daily bread, and entertain themselves using content that is created using their own language and so on. Naturally, in order to make all these things happen, any computational instrument, be it a laptop or a desktop computer, or a smartphone, or something else, should be capable enough to serve all of these things in a man...

   PYTHON,UNICODE,UTF-8,NON-ENGLISH DATA,ASCII CODE     2019-04-10 00:55:19

  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

  Is Java Set ordered or not?

“Is Java Set ordered or not? ” is the most popular question asked when you interview for a Java Developer position. Many fail to answer it, and I have to admit I was one of the many. I have known the answer is “Yes and No” for a long time. No. HashSet is not ordered. Yes.TreeSet is ordered. If the interviewer continues with some follow up questions, I’m not confident that I know the answer then. Why is TreeSet ordered? Are there any other ordered S...

   ORDER,SORTEDSET,HASHSET,JAVA     2021-02-11 06:55:00

  MySQL Index Merge Optimization Practices

In production environment databases, it is often seen that some SQL where conditions include: equal condition on a normal index + primary key range query + order by limit Although using a normal index would be more efficient, the system chooses to use index merge instead in some cases. This article explores such index merge situations. Index Merge Official Introduction   The Index Merge access method retrieves rows with multiple range scans and merges their results into one. Generall...

   INDEX MERGE,MYSQL,PRIMARY INDEX,SECONDARY INDEX     2024-09-10 04:52:26

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