wmitchell wrote:
Hi All,
Ive been working michael nolls multi-node cluster setup example
(Running_Hadoop_On_Ubuntu_Linux) for hadoop and I have a working setup. I
then on my slave machine -- which is currently running a datanode killed the
process in an effort to try to simulate some sort of failure on the slave
machine datanode. I had assumed that the namenode would have been polling
its datanodes and thus attempted to bring up any node that goes down. On
looking at my slave machine it seems that the datanode process is still down
(I've checked jps).
That's up to you or your management tools. The namenode knows that the
datanode is unreachable, but doesn't know how to go about reconnecting
it to the network. Which, given there are many causes of "down", sort of
makes sense. The switch failing, the hdds dying or the process crashing,
all look the same: no datanode heartbeats.
