Pgsql error after optimization could not create semaphores:no space

Server 32G Memory Space

Parameter optimization

$ VI postgresql.conf

Shared_buffers = 3072MB

Max_connections = 4000

Work_mem = 4MB

Effective_cache_size = 4GB

Maintenance_work_mem = 512MB

Wal_buffers = 256

Specific optimization parameter Interpretation reference: 70233820

Error starting Service

$ pg_ctl-d/data/pg_data Start

Server starting

$ log:could Not create IPV6 socket:address family not supported by protocol

Fatal:could not create Semaphores:no space left on device

detail:failed system call is Semget (5432124, 17, 03600).

Hint:this error does *not* mean that you had run out of disk space. It occurs when either the system limit for the maximum number of semaphore sets (Semmni), or the system wide maximum Numbe  R of Semaphores (Semmns), would be exceeded.  You need to raise the respective kernel parameter. Alternatively, reduce PostgreSQL ' s consumption of semaphores by reducing its max_connections parameter.

The PostgreSQL documentation contains more information on configuring your system for PostgreSQL.

Log:database system is shut down

Analysis:

This is because the configuration of the shared memory in the kernel parameter limits the maximum number of connections, the specific reference blog: https://www.cnblogs.com/xiaotengyi/p/5439231.html

Workaround:

# vi/etc/sysctl.conf

Kernel.sem = 50100 128256000 50100 2560

Overloaded configuration

# sysctl-p

Vm.min_free_kbytes = 409600

Vm.vfs_cache_pressure = 200

vm.swappiness = 0

Fs.file-max = 6815744

FS.AIO-MAX-NR = 1048576

KERNEL.SYSRQ = 1

Kernel.sem = 50100 128256000 50100 2560

Net.core.rmem_default = 2621440

Net.core.wmem_default = 2621440

Net.core.rmem_max = 2621440

Net.core.wmem_max = 2621440

Net.ipv4.tcp_rmem = 4096 655360 2621440

Net.ipv4.tcp_wmem = 4096 655360 2621440

Pgsql error after optimization could not create semaphores:no space