I would recommend staying away from /etc/hosts and using DNS if at all
possible.
Then you can set up your machine names, aliases and reverse look up files in
one place.
If the IP Address changes, it doesn't matter since you can either use the
hostname in DNS or the alias.
Since IP address changes are infrequent, I'd recommend using just the hostnames
and then save CNAME (aliasing) for the NN or JT.
With respect to your problem... What does your network look like and how did
the IP address change?
There could be routing issues between boxes?
Can you ping the other machines by IP addresses?
What's your netmask? (255.255.255.0 or 255.255.0.0)
And since you're using /etc/hosts you need to make sure you've correctly
changed all of the IP addresses and that you're also using only one nic card.
HTH
-Mike
> Date: Thu, 11 Nov 2010 16:59:07 +0530
> Subject: Impact of changing node IP
> From: hsreeku...@clickable.com
> To: user@hbase.apache.org
>
> Hi,
>
> I recently had an IP reshuffle, thereby changing the IP addresses of
> all nodes. I had used aliases everywhere in hadoop and hbase config
> directories. So, I think I only need to change the IPs in the /etc/hosts
> file, which is what I did. But ever since the IP change, I am getting a lot
> of HBaseRPC: Could not connect to 192.168.x.y:60020, where 192.168.x.y are
> the new IPs. I am unable to figure out the reason for these errors. Do I
> need to update the IPs anywhere else as well? I have also found that the
> datanode VERSION files have mention of the old IPs:
>
> #Thu Nov 11 15:50:49 IST 2010
> namespaceID=815609148
> storageID=DS-1497184272-192.168.0.158-50010-1288777337532
> cTime=0
> storageType=DATA_NODE
> layoutVersion=-18
>
> (192.168.0.158 is the old IP of the datanode which has this VERSION file. I
> have found the same old IPs in the other datanodes as well.)
>
> So, do the VERSION files also need to be updated?
>
> thanks,
> Hari
