1. A job is killed is a normal behavior. Since by default, hadoop will enable the speculative executions, which means it will create two attempts for the same mapper and once one of the attempt is done, it will just kill the one is not finished.
2. There are lots of possibilities that a mapper take much longer than others. Maybe the input file is much larger, or the data in that mapper might consume more CPU resource. Or the cluster node to handle the mapper is in a heavy load. It is hard to say the root cause without the context. You could try to check the inputs to figure out the reason, or simply re-run the task to see if it still takes much longer time again. BTW, post the question in the mahout mail list probably will get more feedbacks and might be helpful to others has the same problem comparing to send directly to me. :-) Best wishes, Stanley Xu On Tue, May 24, 2011 at 3:15 PM, nn hust <[email protected]> wrote: > Hi, when I use the pfp-growth , I met a question, I find the first map > spend much more time then others, and there will be a task to be killed, I > don't find any error info in the log file, do you know the cause? > > you can see the picture of the hadoop web tools I send to you. > > > Thanks. >
