SEARCH KEYWORD -- linux


  Create cron job on CentOS

These two days, I am building a website and deploying it on a VPS server which uses CentOS 5. I don't have cPanel or Plesk for my account, so I need to install and configure everything myself including Apache, PHP, MySQL and FTP server, also today's topic cron job. Since my website has a ranking algorithm to calculate the rankings of each link and update the ranking on database and I need to calculate the rankings every 5 minutes, so I think to use cron jobs. Here are what I have done which may ...

   cron job,crontab,CentOS,linux,php,example     2012-06-11 09:23:45

  The basics of Client/Server socket programming

  While Client/Server communication model is ubiquitous nowadays, most of them involve socket programming knowledge. In this post, I will introduce some rudimentary aspects of it: (1) Short/Long-lived TCP connection.Short-lived TCP connection refers to following pattern: Client creates a connection to server; send message, then close the connection. If Client wants to transmit information again, repeat the above steps. Because establishing and destroying TCP s...

       2017-09-26 19:43:10

  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

  Run code with multiple files in the same main package in GoLang

To run a GoLang program, there needs to be a main() function defined. In some cases when developing some demo program which has multiple files and just wanna put them in the same main package and this folder is not in GOPATH, how to run the program? Let's say we have following folder structure where the main() function is defined in main.go. If you just run below command, it would fail to start to run the program and gives some error if some struct is defined in other files and being used. PS D...

   EXECUTABLE,GOLANG,MAIN PACKAGE,MULTIPLE FILE     2021-05-15 10:20:10

  OpenLDAP Proxy -- slapd.conf

In the introductory post of OpenLDAP proxy, we mentioned that slapd.conf is the configuration file which tells the slapd service what to do.  Apart from this, there is a dynamic way of configuring slapd where the configurations are stored in LDIF database. In the future, LDIF database will be the one for configuring slapd, the old style of slapd.conf is deprecated. The slapd.conf can be converted to LDIF style using the slapdtest command. slapdtest -f /etc/ldap/slapd.conf -F /etc...

   OPENLDAP,OPENLDAP PROXY,SLAPD,SLAPD.CONF     2017-10-29 04:01:39

  Introduction to the Application of eBPF in Golang

Most of the time, when we develop software or even use software, we play within the safe boundaries of the operating system. We might not know how the network interface welcomes that IP packet, nor how the filesystem handles the inodes when we save a file. This boundary is called user space, which is where we write applications, libraries, and tools. But there's another world, kernel space, where the operating system's kernel resides and is responsible for managing system resources such as memor...

   EBPF,GOLANG,GUIDE,APPLICATION     2024-10-02 08:46:37

  Using Nlog Logging Framework With Vnext In Asp.Net

In this article, asp.net development company experts will brief you about asp.netVNext and its features. They will also explain how to use NLog Logging framework in Asp.net. Read this article and learn what they want you to understand. Overview of Asp.Net VNext The next level of Asp.Net after Asp.Net 5 is Asp.Net VNext. Currently, the code is run in Asp.Net with same CLR as that of desktop apps. There is a need for cloud optimized version of Asp.Net for getting higher throughput with lesser memo...

   ASP.NET ,ASP.NET DEVELOPMENT COMPANY,ASP.NET VNEXT     2016-10-26 01:14:53

  Using public key authentication in SSH

SSH is a popular cryptographic network protocol for secure network service operation. It is frequently used in remote server login. For a system administrator or software developer, SSH is frequently used to access remote servers or development servers or testing servers etc.  To login with SSH, there are different authentication mechanisms : password, public key and interactive etc. If a remote server needs to be accessed frequently, password authentication may be too troublesome as p...

   LINUX,DEBUG,SSH,PUBLIC KEY     2016-09-10 05:55:46

  PHP buffer: output_buffering and ob_start

buffer is one piece of memory section, it is usually 4Kb in Linux. It is mainly used between different devices with different speed or different priorities. With buffer, the waiting time between different processes will be reduced. Here is one simple example, when you type something in a text editor, every time when you type a character, the operating system will not write it to the disk directly, instead it will write it to buffer first When the buffer is full, the data in the buffer will be wr...

   PHP buffer,output_buffering,ob_start     2013-06-20 22:54:15

  Memory related exception analysis in Java

Java Virtual Machine Specification divides the memory of JVM into several areas : Heap, Stack, The Program Counter register and Method area etc. In HotSpot JVM, heap is composed of Young, Tenured and Perm. There are different OutOfMemory error can happen in different memory area. Next is an overview of some of these OOM errors. StackOverflowError The JVM will allow only a specified number of stacks created nested. An JVM option -Xss can be set to determine the maximum stack size. If the num...

   Java, Memory model, Memory exception, OOM     2015-01-19 06:54:27

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