SEARCH KEYWORD -- HIGH CPU


  One Way to Quickly Locate SQL with High CPU Usage in MySQL

When the CPU usage of a MySQL database rises abnormally, it's necessary to quickly identify the problematic SQL statements. In this post, we try to provide one way to achieve this.  Below are the actual steps. 1. Use the top command to find the threads with the highest CPU usage in the MySQL process. # Find the MySQL process ID ps -ef | grep mysql # Use the process ID to find the thread IDs with the highest CPU usage: top -H -p In top, press P to sort by CPU usage. Note the thread ID, fo...

   MYSQL,DEBUG,HIGH CPU,SLOW QUERY     2024-08-01 21:25:48

  Why Apple Mac switches its CPU? The war between Intel and ARM

About three months ago, the new iPad Pro was released and it supports touch pad and mouse. It conveys a clear message to users that they want people to treat iPad Pro as a laptop.  As we know, iPad and iPhone are both using iOS, if iOS can run on laptop,  it means MacOS and iOS can merge and become a unified OS. And if Mac and iPhone can share the same OS, it means the same app can run in all places. It is becoming clearer and clearer that Apple is planning to do this exact thing. Late...

   APPLE,INTEL,ARM,WWDC,A14     2020-06-20 00:19:02

  32-bit vs 64-bit

I have knowledge on 32-bit vs 64-bit, but not very clear minded. Here is a good article I found about it. http://www.techsupportalert.com/content/32-bit-and-64-bit-explained.htm   Understand there are 3 things involved: CPU, OS and application. To work on 64-bit, first thing first is: you need a 64-bit CPU. 64-bit CPU usually provide emulation for 32-bit system. Though some 32-bit application still cannot run on 64-bit OS, because they might contain 16-bit code. 32-bit system won't have com...

       2015-12-08 03:04:01

  Practice of using spinlock instead of mutex

Spinlock and mutex are two important concepts in multithreading programs. They are used to lock some shared resource to prevent concurrent access which may affect data consistency. But they do have differences, what are the differences? when should we use spinlock instead of mutex? The Theory In theory, when a thread tries to lock a mutex and it does not succeed, because the mutex is already locked, it will go to sleep, immediately allowing another thread to run. It will continue to sleep until...

   Spinlock,Mutex,Concurrency     2014-04-19 21:54:12

  How does GoLang know how many CPUs to use?

When running lscpu command on Linux, it will list the CPU info on the machine. Take one example where there is one CPU with 2 cores and each core has two threads which indicates there are 4 cores available. Now let's see how many cores GoLang program would identify. From output, NumCPU and GOMAXPROCS both output 4 which is expected. How does go runtime get this info, does it get it through similar command like lscpu or /proc/cpuinfo? Let's dig more in GoLang's source code. In runtim...

   GOLANG,CPU,NCPU     2020-12-29 23:22:15

  Do we need other languages other than C and C++?

There were hundreds of or thousands of programming languages created since the invention of computer. All these languages have the same target which is to make the computer do what we want it do. So we may find that many languages have the same functions, i.e, one task can be completed by one language can be completed by another language as well. Now we may wonder why we need so many different languages. Can we just have C or C++ since they provide the best performance we need. The answer obviou...

   programming language,C,Erlang     2014-06-14 19:39:40

  Resolve high CPU usage issue caused by file_get_contents in PHP

Sometimes a Linux server which runs Nginx + PHP-CGI(php-fpm) web service may experience sudden system load increase and the CPU usage is around 100% for many php-cgi processes when checking with top command. If this happens, file_get_contents may be the cause if it's used in the PHP script. In lots of web applications, normally there are lots of API requests based on HTTP. Many PHP developers like to use file_get_contents("http://example.com/") to get the API response because it's simple to...

   PHP,FILE_GET_CONTENTS,PHP-CGI     2018-11-09 21:35:00

  New Android simulator has some big improvements

Message from the Android developer blog, the Android emulator now has a number of improvements and optimizations. It allows developers to develop applications more conveniently.The Android emulator is an important tool for Android developers developing and testing applications. Due to the rapid growth of Android hardware, the simulator has been slightly left behind. The new simulator brings some new functions including support for GPU, the CPU acceleration sensor support, multi-touch input suppo...

   Android, Simulator,GPU,OpenGL     2012-04-10 13:02:31

  Amazon is a good company but doesn't have the best business model

Public opinion about a company is usually based on its performance. If it performs well, people will praise it, otherwise people will blame it. In 1999, Apple was still a broken apple(Steve Jobs's talent and effort was paid off yet). Public opinion about Apple was the closed model caused Apple's failure. They built hardware themselves, developed software themselves and delivered service themselves, this is certainly not sustainable. But Steve Jobs let everyone see this new model. In order to con...

   Business model,Amazon,Apple, Microsoft     2013-07-02 11:34:45

  Simple explanation about process and thread

Process and thread are two basic concepts of operating system, but they are a bit abstract which cannot be  mastered easily. There is an analogy which explains these concepts very well. 1. The kernel of the computer is CPU, it handles all the computing tasks, it's like a factory and will run all the time. 2. Assume there is power limitation for the factory, it can only supply to one unit once,i.e, when one unit is working, other units must stop and wait. The meaning behind this is that eac...

   Process,Thread,CPU,Operating system     2013-04-24 11:33:10

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