zombie mutation

Preface recently, due to studying java, many labels will be opened in chrome, and some extensions will be used to remind you of some emails and other things. The results will often get inexplicably stuck to my desktop program, the reason is that the Zombie process is generated. I will not talk about the cause of Zombie here. I just want to briefly talk about how to find the

entrusted to the INIT processAbc++; printf ("child:%d,parent:%d\n", Getpid (), Getppid ()); printf ("abc:%d", ABC); Sleep ( -); } printf ("Fork after...\n");}Before Fork pid:27709parent:pid:27709Abc:11child:27710,parent:27709Fork after ...DISDA 27710 1 0 10:47 pts/1 00:00:00./reviewDISDA 27713 25948 10:47 pts/3 00:00:00 ps-efWe execute the program because the child process enters sleep (100), and the parent process exits first. With the PS-EF command we can know that at this point the parent pr

ObjectiveThis article will be divided into two parts, the first part of the implementation of a pair of concurrent back-up Server/client program (see the previous article in this part can not see the repetition); The second part is the server to add a zombie subprocess automatic cleanup mechanism.So how does the server implement concurrency? How can there be a zombie process? What is a

When we look at host performance using the top command, we see a zombie keyword in the second row that represents the meaning of the zombie process. Zombie Process: When a process exits, it sends a SIGCHLD signal to the parent process, always ignoring the SIGCHLD signal by default, at which point the process state remains in memory until the parent process collec

Zombie Processes (Zombie process) The process has finished executing, but the resource occupied by the process has not been reclaimed. This process is called a zombie process . At the time each process exits, the kernel frees all of the process's resources, contains open files, occupies memory, and so on. however , it still retains certain info

Botnets In the previous article, we have understood the concepts of parent and child processes, and have mastered the usage of System Call exit, but few people may realize that, after a process calls exit, it does not disappear immediately, but leaves a data structure called Zombie.Among the five States of a Linux Process, a zombie process is a very special one. It has abandoned almost all the memory space, no executable code, and cannot be scheduled,

The zombie process in the Linux system and the zombies in the real world (although I have not seen it) are similar, although they are dead, but because no one gives them a corpse, they can walk around. A zombie process is a process that has been terminated, but still retains some information, waiting for its parent process to bury it. How did the zombie process o

What botnets? Here is a brief introduction. You can find the details on the Internet: BotnetsThis means that the child process has exited, but the parent process has not exited, and wait is not performed on the child process. As a result, the resources of the child process are not released and are still occupied in the memory, as a result, it becomes a process like a zombie (a zombie cannot act, but occup

OrderThe Zombie (zombie) process is simply: when a child process exits, the parent process does not properly handle the sigchild signal it emits, causing the child process to stay in a zombie state to wait for its parent process to corpse, and the child process in this state is a zombie process.Because concurrent serve

PS --forest ASCII Art process tree 2 How to clear the zombie process:1. Rewrite the parent process and bury it after the child process dies. The concrete approach is to take over the SIGCHLD signal. After the child process dies, the SIGCHLD signal is sent to the parent process, and after the parent process receives this signal, the waitpid () function is executed to corpse the child process.This is based on the principle that even if the parent proces

Zombie process ):In a UNIX system, a process is finished, but its parent process is not waiting (wait/waitpid is called), then it will become a zombie process. however, if the parent process of the process has ended, the process will not become a zombie process, because at the end of each process, the system will scan all processes running in the current system,

LinuxOn the server, there are a number of Zombie Process, here's a quick way to find and eliminate these zombie processes First, we can use the top command to see whether the server currently has a zombie process, in the following figure can see the number of zombie processes, if the number is greater than 0, it mean

Orphan process and zombie processI. Definition: What is orphan process and zombie processZombie Process: A child process exits if its parent process has not yet called wait () or waitpid (). This child process is the zombie process.Orphan process: One parent process exits, and one or more of its child processes are still running, then those child processes will b

This article to share the content is the PHP implementation of the system programming of the multi-process programming introduction and orphan process, zombie process, has a certain reference value, the need for friends can refer to Multi-process programming is also an important aspect of system programming, but PHP programmers often do not need to be concerned with multi-process problems, because Web servers or PHP-FPM have helped us manage process

IOS Performance Tuning series: use Zombies to dynamically analyze zombie objects in the memory and optimize zombies Hardware wide: The fourth article in the IOS Performance Tuning series, which is expected to be updated continuously over 20 articles. The first two articles, IOS Performance Tuning series: Analyze static analysis and IOS Performance Tuning series: using Instruments to dynamically Analyze memory leaks, focus on memory leaks. This article

The relentless brutality of the zombie network is now commonplace, and we are just considering that the bad guys are the ones who have invaded the user's accounting machine without being discovered by the user. Zombie Network has long been used in accounting machines in various equipment, and some of the control mechanism to pretend. With the appearance of the user friendly but not safe use of software con

Zombie process (zombie process ):When a process stops running (exit), all its resources and memory space will be released for use by other processes; however, it retains a record in the Process Table of the OS kernel, including the process ID, exit status, and running time of the process. This information is convenient for the parent process of the process to obtain its exit status at any time (that is, why

When a process calls the Exit command to end its own life, it is not actually destroyed, but it leaves behind a data structure that becomes zombie. The zombie process is a very special kind of because it has given up almost all of the memory space, no executable code, can not be scheduled, only in the process list to keep a position, log the process of the exit status and other information for other process

the voice of bots is no different. After several days of rumor, I felt that the zombie chicken was an old smell. I didn't expect the news to be filled with old wine again. I continued to write out this old article for Netease's exploration. At that time, I also published a cut-down article. Now I wrote my blog, which is a complete expression of my point of view. It is inappropriate to call a fast-growing chicken as a large-sized white-feather bro

What is a zombie process? When a process calls the exit command to end its own life, it is not actually destroyed by a zombie process, but left a zombie process called Zombie) (The system calls exit to exit the process, but it is only limited to converting a normal process into a z