I’ve received this error while starting mongo in shell while installing on
[root@master ~]# mongod --version
db version v3.2.3
git version: b326ba837cf6f49d65c2f85e1b70f6f31ece7937
OpenSSL version: OpenSSL 1.0.1e-fips 11 Feb 2013
allocator: tcmalloc
modules: none
build environment:
distmod: rhel70
distarch: x86_64
target_arch: x86_64
[root@master ~]# mongo --version
MongoDB shell version: 3.2.3
CentOS Linux release 7.2.1511 (Core)
WARNING: soft rlimits too low. rlimits set to 4096 processes, 64000 files. Number of processes should be at least 32000 : 0.5 times number of files.
Solution
vim /etc/security/limits.d/90-nproc.conf
Then put in
mongod soft nproc 64000
and
reboot

Thanks Justin. you saved my day.
You are welcome.