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  The Internet : from 1969-1974

Internet was born 43 years ago. There are some big events in the history of Internet development. In my opinion, most of the big events happened at the first five years, i.e, from 1969-1974.  1969 : ARPANETThe Advanced Research Projects Agency Network (ARPANET), was the world's first operational packet switching network and the core network of a set that came to compose the global Internet. The first ARPANET transmission was between Stanford Research Institute and UCLA on 29th, October 1969...

   Internet,History     2012-06-22 09:55:51

  Get Facebook, Twitter and YouTube back

Facebook, Twitter and YouTube have become part of many people's daily network life. People hang around these sites to network with known and unknown friends, to know about the latest news and to relax with fancy video clips. But what will you feel if all of a sudden you cannot access them? Want to experience this? Go behind the GFW(Great Firewall) of China. Just a joke, but it's real. Huh, you are out of China? Don't worry. Change your DNS server to those located in China. I just experienced it,...

   DNS spoofing, GFW, YouTube, 37.61.54.158     2014-12-20 21:41:34

  Install Open webOS on Linux

HP has just released its first beta version of the webOS, It is said the user experience of webOS is quite impressive, so I immediately had it installed on my PC. There are two versions of Beta release,one embedded version and one Ubuntu version. I briefly share my installation experience of webOS in Linux. In the official document, it says "By 'Linux' we mean 'Ubuntu Linux'", it doesn't support server version and 64 bit version of Ubuntu. Here I use Mint 13. 1. Clone source code from github Add...

   Linux,webOS,Ubuntu,embedded,HP     2012-09-10 19:36:30

  How to do pprof for gRPC service

gRPC is a RPC framework based on HTTP and is frequently used for communications among micro service inside the same organization network. However,  the service functions cannot be accessed via normal HTTP URL as it's not a WEB framework. In this case, how to do pprof on a gRPC service? The trick is starting a HTTP server asynchronously while starting the gRPC service. This HTTP server can be accessed to run prrof debug. go func(){ http.ListenAndServe(":10001", nil) }() Since it uses the de...

   GOLANG,PPROF,GRPC     2021-01-29 23:11:33

  LESS/SASS/Stylus development tools summary

LESS,SASS and Stylus are more and more popular among developers. More and more people are using these three tools now. Here we introduce some development and testing tools which can make our development process simpler. SublimeText Many front-end developers are now using Sublime Text 2 as their main text editor, there are many plugins in Sublime Text as well. We can use Ctrl+Shift+P –> install package to search relative plugins. Less Sublime Less build Sublime Less2css Less snippets Su...

   LESS,SASS,Stylus,CSS     2013-02-23 22:45:02

  Some cases where MySQL cannot be started

After installing MySQL, when we try to start MySQL, sometimes we may not be able to start it. The reasons can be different. We share some general cases where MySQL cannot be started. Case 1: Directory or file permission issue If the permission is set wrongly in MySQL's $datadir and its sub directories or files, MySQL will not be able to read and write files normally. Error message: mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/data /usr/local/mysql/bin/mysqld_safe: lin...

   MySQL,Error,Log     2013-08-15 03:32:36

  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

  ByteBuffer in Java

ByteBuffer is introduced in java.nio since Java 1.4. It provides a way of representing raw structured data such as from a file or from network. It enables fast access of underlying data compared to traditional ways like byte[] Prior to Java 1.4, if you want to represent a structured raw data, you need to create a byte[] and then having a set of checks to delimit the byte array to get the expected tokens. There are three ways to create a ByteBuffer: Wrapping an exiting array by calling ByteBuffe...

   JAVA,BYTEBUFFER,ALLOCATION     2015-07-08 03:17:44

  errGroup in GoLang explained

Today, let's talk about the usage and applicable scenarios of errGroup, which is often used. Why is it useful? Generally, when we use goroutine, we cannot return a value. If you want to pass out the result of the goroutine execution, you usually have to use the channel. The errGroup package is suitable if you want to know when the goroutine you opened encounters an error during execution and stop working, and I need to know the error value. errGroup usage The package needs to be downloaded and i...

   GOLANG,ERRGROUP,WAITHROUP,CONCURRENCY     2023-05-27 23:58:20

  <=> operator in MySQL

Have you ever seen "<=>" in a SQL query while using MySQL? Does it mean less and equals to and greater than? Actually if you consider it as the union of <= and =>, great, you are close to it. This is one form of equal operator in MySQL, it has the similar meaning to the = operator with some subtle difference. According to MySQL documentation, <=> is NULL-safe equal. This operator performs an equality comparison like the = operator, but returns 1 rather than NULL if both operand...

   MySQL,NULL safe,<=>     2014-03-24 06:23:22

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