The type of scheduled task software under Linux system

  The type of scheduled task software under Linux system

Strictly speaking, there are a lot of timing task software under Linux system, for example:at,crontab, Anacron .

at: For scheduling task commands that are executed only once, for example: One night needs to deal with a task, just the night of the day, is a sudden task. To execute the at command, you also need to start a service called ATD , which is never needed in an old boy's job. Therefore, we recommend that we do not go into the study, so we can explain to this end.

[Email protected] study_20160420]# chkconfig--list|grep ATD

ATD 0:off 1:off 2:off 3:on 4:on 5:on 6:off

[Email protected] study_20160420]# chkconfig--list ATD

ATD 0:off 1:off 2:off 3:on 4:on 5:on 6:off

crontab: As mentioned earlier, this command can perform tasks periodically, for example: Server time synchronization every five minutes. To execute crontab This command, you also need to start a service crond , this crontab command is the most common command in production work, Please make sure you master the mastery.

[Email protected] study_20160420]# chkconfig--list Crond

Crond 0:off 1:off 2:on 3:on 4:on 5:on 6:off

anacron: This command is primarily intended for servers that do not have a server-hour boot,andAnacron does not specify a specific time to perform tasks. It is a task that is performed on a daily cycle or after every system boot. It detects the tasks that should be performed during a server outage, but does not perform the task and executes the task again.

Tips:

1) What we call the crond Service is the running program, and the command that the crontab command user uses to set the timing rules.

2) Crond Service is an important service commonly used in enterprise production, while at and anacron are seldom used and can be neglected.

3) crond services are used by almost every server .

4) A good enterprise will develop a distributed scheduled task project plan.

This article is from the "Yau Xin Zhai" blog, please be sure to keep this source http://mofei.blog.51cto.com/6840705/1767699

The type of scheduled task software under Linux system