Namenode does not initiate any connections.
The ip address for a Datanode that Namenode gives to client is as the IP address that Datanode uses to connect to Namenode (i.e. Namenode just does getRemoteAddress() on the connection from Datanode). There is no option to change this.
If you just want the clients outside the firewall, do you think https://issues.apache.org/jira/browse/HADOOP-1822 does the job?
Raghu. Stu Hood wrote:
Hey gang, We're getting ready to deploy our first cluster, and while deciding on the node layout, we ran into an interesting question. The cluster will be behind a firewall, and a few clients will be on the outside. We'd like to minimize the number of external IPs we use, and provide a single IP address with forwarded ports for each node (using iptables). We've used this method before with simpler "client -> server" protocols, but because of Hadoop's "client -> namenode -> client -> datanode" protocol, I'm assuming this will not work by default. Is it possible to configure the namenode to send clients a different external IP/port for the datanodes than the one it uses when it communicates directly? Thanks a lot! Stu Hood Webmail.us "You manage your business. We'll manage your email."®
