I believe multicast is limited to the subnet the machines are on. It works
nice to get a cluster up and working quickly. The drawback is that in order
to have multiple clusters on the same subnet, each cluster would need it's
on name. I'm not sure about the group ip setting.
Unicast allows you to specify which nodes to contact to form a cluster.
Unicast takes a bit more work to manage, but gives you more control as well.
If you have multiple interfaces on a machine or multiple ip address, you
can either specify what address to listen on or have the node listen on all
We were originally using multicast, but switched to unicast locally. We
also use unicast on AWS to make it easier to run multiple clusters.
On Wed, Jan 25, 2012 at 3:31 PM, Wes Plunk email@example.com wrote:
multicast discovery or unicast discovery?
Would someone explain the differences? Primarily in how flexible the
cluster/node design will be. I'm wanting to be able to spin up new
nodes without having to require the java client or other nodes to make
configuration changes (which seems to be what I'd have to do if I ran
Also, multicast has a "group" setting with an ip address. Where does
that ip address come from? Do all nodes use the same group ip address?
Is that group ip address also a node?
Also, multicast has a "address" to bind to setting. I'm unclear as to
how this could be used. The example on the site is setting it to
"null" so that it binds to all available networks. How does binding it
to a network ip address change the behavior of the multicast discovery?
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