RHEL8 released more than six months, they heard that the Red Hat exams to become a problem, want to pay close attention to test the next RHCE, but of a wish.
Red Hat was founded in 1993, it is the world's first income of over $ 1 billion revenue company, headquartered in the United States, offices around the world. Red Hat as the world's leading open source and Linux provider, and its products have been widely recognized and the use of industry, especially RHEL system Linux system has a high market share in the industry. In addition to Red Hat provides operating system, but also provides the virtualization, middleware, applications, management, and service-oriented architecture solutions. Red Hat certification is the Red Hat Linux company introduced certification which is considered to be one of the highest areas of the value of Linux certification and the whole industry IT. Red Hat certification exams on the machine used in all forms, in the ability to examine students' theoretical foundation also investigated practice hands and troubleshooting capabilities. Red Hat certification for Red Hat developed a comprehensive professional assessment and certification standards, its certification including Red Hat Certified System Administrator (RHCSA), Red Hat Certified Engineer (RHCE) and Red Hat Certified Architect (RHCA).
This is also to test the RHCSA and RHCE. 
Postscript
This book is of high quality self-paced tutorial Linux technology based on the latest Red Hat Linux system over by the National Architect (RHCA) co-written, extremely suitable for introductory tutorial or lecture Linux technical support materials, is currently the most read of Linux textbook, Linux is the most valuable laboratory manual. Chapters include:
Chapter 0 Let's talk about learning methods and Red Hat systems.
Chapter 1 Deploying virtual environments installed linux system.
Chapter 2 novice Linux commands must master.
Chapter 3 pipe symbol, redirection and environment variable.
Chapter 4 Vim editor with Shell command script.
Chapter 5 user identity and file permissions.
Chapter 6 disk storage structure and division.
Chapter 7 Using LVM and RAID disk array technology.
Chapter 8 Iptables and Firewalld firewall.
Chapter 9 remote host using ssh service management.
Chapter 10. Using Apache service deployment static websites.
Chapter 11 Transferring files using Vsftpd.
Chapter 12. Samba or NFS file sharing.
Chapter 13 Using Bind provide domain name resolution services.
Chapter 14 Using DHCP dynamic management host address.
Chapter 15 using Postfix and Dovecot-premises messaging system
Chapter 16 Using Squid proxy cache deployment services.
Chapter 17 Using iSCSI network storage service deployment.
Chapter 18 Using MariaDB database management systems.
Chapter 19, PXE + Kickstart to deploy an unattended installation.
Chapter 20 LNMP use architecture to deploy dynamic web environment.
Interested in Linux have to add a collection of online learning website is https://www.linuxprobe.com/chapter-00.html
annex:
Linux introductory tutorial, https://www.linuxprobe.com/docs/LinuxProbe.pdf
Linux command Daquan: https://www.linuxcool.com/