How can I limit the maximum number of processes and maximum file handle opening in Linux?

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Ulimit Resources used by the shell startup process

1. Syntax format:

ulimit [-ACDFHLMNPSSTVW] [size]

2, Parameter introduction :

-H Sets the hardware resource limit .

-S sets the software resource limit .

-a displays all current resource limits .

-C size : Sets The maximum value of the core file . Unit : Blocks

-D Size: sets the maximum value for the data segment . Unit : Kbytes

-F Size: Sets the maximum value for the created file . Unit : Blocks

-L Size: sets the maximum value of the locked process in memory . Unit : Kbytes

-M Size: Sets the maximum number of resident memory that can be used . Unit : Kbytes

-N Size: Sets the maximum number of file descriptors that the kernel can open at the same time . Unit : N

-P Size: sets the maximum value of the pipe buffer . Unit : Kbytes

-S Size: sets the maximum value of the stack . Unit : Kbytes

-T size : Sets the maximum limit for CPU usage time . Unit : Seconds

-V Size: Sets the maximum value for virtual memory . Unit : Kbytes

-u number: Set user max Processes (max user processes)

3. Linux for each user, the system limits its maximum number of processes. To improve performance, you can set the maximum number of processes per Linux user according to the device resource situation, I set the maximum number of processes for a Linux user to 10000 :

Ulimit-u 10000

4. For Java applications thatneed to do many socket connections and leave them open , it is best to use ulimit-n xx Modifies the number of files that each process can open, with a default value of 1024x768. Increase the number of files that each process can open to 4096, which defaults to 1024x768.

Ulimit-n 4096

5.some important settings that are set to Unlimited (unlimited) are:

Data segment Length:ulimit-d Unlimited

Maximum memory size:ulimit-m Unlimited

stack size:ulimit-s Unlimited

CPU time:Ulimit-t Unlimited

virtual Memory:Ulimit-v Unlimited

6. the maximum number of processes and maximum file opening limits of the Linux system are lifted :

1)vi/etc/security/limits.conf, add the following line

* Soft noproc 65535 * hard noproc 65535 * Soft nofile 65535 * hard nofile 65535

Description:* represents for all users

Noproc represents the maximum number of processes

Nofile is the number of open files representing the maximum file

2), modify the environment variable files for all Linux users:

Shell> vi /etc/ profile

Add the following configuration on the last side:

Ulimit-u 65535 ulimit-n 65535ulimit-d Unlimited ulimit-m unlimited ulimit-s unlimited ulimit-t unlimited ulimit-v u nlimited

Effect:

Shell> source /etc/ profile

Source: Linux commune

How do I remove the maximum number of processes and maximum file handle opening limits in Linux?