Q1:What shall I do if OceanBase Database fails to start and the log contains a "too many open files" error?
A: Run the ulimit -n 655360 command to change the limit on the number of open files. If you cannot change the limit by using the admin user, you can add the following lines to the /etc/security/limits.conf file:
soft nofile 655360
hard nofile 655360
Q2: What shall I do if OceanBase Database fails to start and the log contains a failed to open file error?
A: Directory permissions are incorrect. Run the following commands to set directory permissions:
chmod 755 -R /data/1
chmod 755 -R /data/log1
chmod 755 -R /home/admin
Q3: When I add a host, the system prompts that the host cannot be added. What shall I do?
A: Before the system adds a host, it will attempt to connect the host via SSH using the root and admin users. If the connection fails, an error is reported. This problem may be caused by an inability to log in as the root user via SSH. To fix this, you need to modify the SSH configuration by adding PermitRootLogin yes to the /etc/ssh/sshd_config file, and restart the SSH service.
Q4: What shall I do if I cannot access the ports after the process is started as normal?
A: Check the iptables. The iptables of the EulerOS system may fail to close, in which case you may run the iptables -F command to clear its rules.