In our previous recipes, we installed or configured Hadoop clusters as user hadoop. But, in production, it is good to run jobs as different users and also the Hadoop daemons can be separated to run with different user IDs, so as to have better control and security.
The security aspects will be covered in the security chapter, but it is important to understand the user segregation and grouping users per project or business units.
In this recipe, we will see how to create users and groups for job submission. These recipes do not talk about the HDFS user permissions or file ACLs, but only about the permission to submit jobs and what percentage of cluster capacity each user or department can use within an organization.