To let students to have some hand-on experience of using hadoop, we want them to compile and run the wordcount example.
I have tested the codes last week and everything worked well at that time. However, it cannot be completed these days. At most of time, when the students (and I also test again) run the wordcount, the reducer stacks when the task is finished around 11% to 20%. And sometimes, it works well again.
I used IBM InfoSphere BigInsights Basic 1.4 64b - PAYG for all my nodes.
Can anyone help me with this issue?
And other problem just occured this afternoon. I find there are some files/directories under my hadoop file system and are not put by me. I am a little confused, because I think the virtual hadoop file systems of differenct users are isolated. Am I wrong?