Developer Tip: Why Did My Job Fail with Error Message “Class alluxio.hadoop.FileSystem not found”?

From time to time, a question pops up on the user mailing list referencing job failures with the error message “java.lang.ClassNotFoundException: Class alluxio.hadoop.FileSystem not found“. This post explains the reason for the failure and the solution to the issue when it occurs. Why does this happen? This error indicates the Alluxio client is not available at runtime. … Continued