ssh fails to run with "Resource temporarily unavailable" errors

Issue

• Invokingin SSH is not possible with following error stack in /var/log/secure:

sshd[14053]: fatal: fork of unprivileged child failed
sshd[3821]: error: fork: Resource temporarily unavailable

• Please let us know the reason and resolution for the same as our application is not getting processed due to ssh failure leading to sftp failure.