Two problem scenarios and solutions.
Problem scenario: You installed Cloudera 5 (Hadoop) on CentOS 7.2 for the first time. You tried to start the Cloudera database service. But you get an error that it failed.
You run this: systemctl status cloudera-scm-server-db.service
The results include this fragment: " ... Failed to start LSB: Cloudera SCM Server's Embedded DB."
How do you start the Cloudera DB service?
Solution
Disable SELinux.
- If you find the file /etc/sysconfig/selinux, modify it. Replace "SELINUX=enforcing" with "SELINUX=disabled". Reboot the Linux server.
- If you cannot find the file, e.g., you are on RHEL 7.3, find /etc/selinux/config and modify it. Replace "SELINUX=enforcing" with "SELINUX=disabled". Reboot the Linux server.
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Problem scenario: You installed Cloudera 5 (Hadoop) on Linux. But you cannot reach the web UI from a regular Windows workstation from any port. What should you do?
Solution
Shut off the firewall on the Linux server or reconfigure it. You may want to research the consequences of this change before doing it.