Shulou(Shulou.com)06/01 Report--

Usage scenario: the threshold value may need to be adjusted in production environment (such as Oracle, ELK, file server, etc.) due to the default number of processes, resource limits, sessions, and other deficiencies. For those of you who have experience here, I would like to give you some advice:

1. Try not to restart (temporary adjustment, and modification will take effect permanently)

1.1) the production server does its best not to restart indiscriminately, which is a lot of risk.

2. There are two issues to consider when restarting

2.1) is the business running normally?

2.2) do you want to back up data?

2.3) is the data available?

1. Temporary effect:

Ulimit-HSn 65536 (default 1024)

Detailed description of parameters:

# ulimit is used for the resources used by shell to start the process.

-H sets hardware resource limits.

-S sets software resource limits.

-a displays all current resource restrictions. You can use this command to see how the process is consuming resources.

-c size: sets the maximum value of the core file. Unit: blocks

-d size: sets the maximum value of the data segment. Unit: kbytes

-f size: sets the maximum value for creating files. Unit: blocks

-l size: sets the maximum value for locking processes in memory. Unit: kbytes

-m size: sets the maximum amount of resident memory that can be used. Unit: kbytes

-n size: sets the maximum value 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 stack value. Unit: kbytes

-t size: sets the maximum limit of CPU usage time. Unit: seconds

-v size: sets the maximum value of virtual memory. Unit: kbytes 5

2. Permanently effective: (please keep renzhiyuan.blog.51cto.com for reprint)

Vim/etc/security/limits.conf* soft nofile 65536 * hard nofile 65536 * soft noproc 10240 * hard noproc 10240

Third, syntax parameters:

* stands for all users

Soft hard soft and hard

Noproc represents the maximum number of processes

Nofile represents the maximum number of file openings

Fourth, the user authentication option also needs to modify the pam authentication module.

# attach

Session required pam_limits.so

Note: someone pointed out the difference between 32-bit and 64-bit, searchable server 65536 entries to explain the principle, not described here, 64-bit system is a reference to the postal savings head office configuration.

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