These RPMs are needed to reinstall cron if you install MySQL5.7 on RHEL6 and cron disappears (as it will)

• cronie-1.4.4-16.el6_8.2.x86_64.rpm
• cronie-1.4.4-16.el6_8.2.x86_64.rpm.md5
• cronie-anacron-1.4.4-16.el6_8.2.x86_64.rpm
• cronie-anacron-1.4.4-16.el6_8.2.x86_64.rpm.md5
• cronie-noanacron-1.4.4-16.el6_8.2.x86_64.rpm
• cronie-noanacron-1.4.4-16.el6_8.2.x86_64.rpm.md5
• exim-4.92.3-2.el6.x86_64.rpm
• exim-4.92.3-2.el6.x86_64.rpm.md5