Alternatively, maybe all the TaskTracker nodes can contact the NameNode and JobTracker, but cannot communicate with one another due to firewall issues? - Aaron
On Mon, Feb 2, 2009 at 7:54 PM, jason hadoop <jason.had...@gmail.com> wrote: > A reduce stall at 0% implies that the map tasks are not outputting any > records via the output collector. > You need to go look at the task tracker and the task logs on all of your > slave machines, to see if anything that seems odd appears in the logs. > On the tasktracker web interface detail screen for your job, > Are all of the map tasks finished > Are any of the map tasks started > Are there any Tasktracker nodes to service your job > > On Sun, Feb 1, 2009 at 11:41 PM, Kwang-Min Choi <kmbest.c...@samsung.com > >wrote: > > > I'm newbie in Hadoop. > > and i'm trying to follow Hadoop Quick Guide at hadoop homepage. > > but, there are some problems... > > Downloading, unzipping hadoop is done. > > and ssh successfully operate without password phrase. > > > > once... I execute grep example attached to Hadoop... > > map task is ok. it reaches 100%. > > but reduce task freezes at 0% without any error message. > > I've waited it for more than 1 hour, but it still freezes... > > same job in standalone mode is well done... > > > > i tried it with version 0.18.3 and 0.17.2.1. > > all of them had same problem. > > > > could help me to solve this problem? > > > > Additionally... > > I'm working on cloud-infra of GoGrid(Redhat). > > So, disk's space & health is OK. > > and, i've installed JDK 1.6.11 for linux successfully. > > > > > > - KKwams > > >
