Why am I getting the Hadoop command and not finding an error?
I have installed and configured Hadoop on my Linux machine. I trying to run a sample MR job. And, started the Hadoop via the command /usr/local/hadoop/bin/start-all.sh and It gives me output as shown below.
namenode running as process 7876. Stop it first.
localhost: datanode running as process 8083. Stop it first.
localhost: secondarynamenode running as process 8304. Stop it first.
jobtracker running as process 8398. Stop it first.
localhost: tasktracker running as process 8612. Stop it first.
So I thought it is configured successfully. But when I am trying to run the below command it is giving an error Hadoop command not found, as shown below
jeet@jeet-Vostro-2520:~$ hadoop fs -put gettysburg.txt /user/jeet/getty/gettysburg.txt
hadoop: command not found
I am new to Hadoop, please address this issue.
The reason you are getting this error “Hadoop: command not found” is that you have not exported the Hadoop path in the environment variable.
Below are the steps that you can follow to remove this error:
open ~/.bashrc file (like gedit ~/.bashrc)
Add the following command in the same file and save it:
export PATH=$PATH:/usr/local/hadoop/bin/
Following the above steps, enable you to run the Hadoop commands from any directory.
Note:
The error “ Hadoop: Command not found” means that the command isn't in your search path.
Answer (1)
If you're encountering a situation where you're using the Hadoop command but not receiving an error message, there could be several reasons for this:
Successful Execution: The Hadoop command may be executing successfully without encountering any errors. In this case, it's doing what it's supposed to do, and no error message is generated.
Error Suppression: Some Hadoop commands or configurations may suppress error messages or output unless there's a critical issue. Check if there are any flags or options that control error output or verbosity.
Logging: Errors or warnings may be logged to a separate file or location rather than being displayed in the console output. Check the Hadoop log files or configuration settings to see if error messages are being captured there.
Permission Issues: If you're running the Hadoop command with insufficient permissions, you might not see errors directly in the console output. Instead, the command may fail silently due to lack of access to certain resources or directories.
Environment Configuration: Ensure that your environment is properly configured to run Hadoop commands. This includes having the Hadoop binaries in your PATH environment variable and the Hadoop configuration files properly set up.
Output Redirection: It's possible that error messages are being redirected to a file or another destination rather than being displayed in the terminal. Check if any output redirection is in place.
Quiet Mode: Some Hadoop commands have a "quiet" or "silent" mode that suppresses non-essential output, including error messages. Check the documentation or command options to see if this mode is enabled.
Version Compatibility: Ensure that the version of Hadoop you're using is compatible with your operating system and other dependencies. Incompatibilities could lead to unexpected behavior, including silent failures.
If you're still unsure why you're not seeing error messages, try running the Hadoop command with increased verbosity or diagnostic options to get more detailed output. Additionally, reviewing the documentation and seeking help from the Hadoop community or support channels could provide further insights.