On 03/07/11 03:11, Raja Nagendra Kumar wrote:
Hi, Instead of depending on local syncup to configuration files, would it be a nice way to adopt JINI Discovery model, where in masters and slaves can discover each other dynamically through a UDP broadcast/heart beat methods
That assumes that UDP Broadcast is supported through the switches (many turn it off as it creates too much traffic), or UDP multicast is supported (as an example of an infrastructure that does not, play with EC2)
This would mean, any machine can come up and say I am a slave and automatically discover the master and start supporting the master with in< x seconds.
How will your slave determine that the master that it has bonded to is the master that it should bond to and not something malicious within the same multicast range? It's possible, but you have generally have to have configuration files in the worker nodes.
There's nothing to stop your Configuration Management layer using discovery or central config servers (Zookeeper, Anubis, LDAP, DNS, ...), which then pushes desired state information to the client nodes. These can deal with auth and may support infrastructures that don't support broadcast or multicast. Such tooling also gives you the ability to push out host table config, JVM options, logging parameters, and bounce worker nodes into new states without waiting for them to timeout and try to rediscover new masters.
