How to view log files in Hadoop？

To view the logs in Hadoop, you can follow these steps:

1. Open the terminal or command prompt on the Hadoop cluster.
2. The logs directory in the Hadoop home directory.
3. log file for the Hadoop namenode with the username and hostname
4. log file for the data node belonging to the user with username “hadoop” on the specified hostname
5. log file for the secondary name node of Hadoop belonging to the specified username(may be a placeholder) and hosted on the specified server.
6. Open the corresponding log file based on the specific type of logs you want to view. You can use a text editor or command-line tool to open them.
7. You can check the information in the log files to understand the status, errors, warnings, etc. of the Hadoop cluster.

Please note that log files may vary depending on Hadoop configuration and log levels, so you may need to view different log files to get a comprehensive view. Additionally, log files may contain a large amount of information, so it is important to be selective when reviewing logs and filter or search based on your specific needs.