Yes, the client uses the same datacenter (us-west-2).
Maybe I haven't explained well the situation. I'm not asking to connect to nodes *without* using a static IP address, but allowing Cassandra to determine the current public address at the time of connection. Spark, for example, uses shell scripts for configuration, so the public IP (in AWS) can be assigned using the command `|curl http://169.254.169.254/latest/meta-data/public-ipv4|`, whatever it is at the time of boot. Cassandra uses a yaml file for the main configuration, so this is impossibile to achieve. Basically I would like to make the client connect correctly on all nodes using their public IPs without being required to know them (the client would discover them dynamically while connecting).


Il 05/10/2015 00:55, Jonathan Haddad ha scritto:
So you're not running the client in the same DC as your Cassandra cluster. In that case you'll need to be able to connect to the public address of all the nodes. Technically you could have a whitelist and only connect to 1, I wouldn't recommend it.

This is no different than any other database in that you would need a public address to be able to connect to the servers from a machine not in your datacenter. How else would you connect to them if you don't provide access?

On Sun, Oct 4, 2015 at 6:35 PM Renato Perini <renato.per...@gmail.com <mailto:renato.per...@gmail.com>> wrote:

    Seems to be not the case when connecting to my (single) data
    center using the java connector with a small client I have
    developed for testing.
    For the broadcast_rpc_address I have configured the local IP of
    the nodes. The cluster works fine and nodes communicates fairly
    well using their local IPs. When I connect to a node (let's say
    node 1) from the outside using the java driver and the node's
    public IP, the cluster discovery uses internal IPs for contacting
    other nodes, leading to (obviously) errors.

    As for AWS, Elastic IPs are free as long as they're associated to
    an instance and the machines are up 24h/7. I have to shut down the
    machines during the night for various reasons, so unfortunately
    they're not totally free for my use case.



    Il 05/10/2015 00:04, Jonathan Haddad ha scritto:
    Public IP?  No, not required unless you're running multiple DCs.

    Where are you running a DC that IPs aren't cheap? If you're in
    AWS they're basically free (or at least the cheapest section of
    your bill by far)



    On Sun, Oct 4, 2015 at 5:59 PM Renato Perini
    <renato.per...@gmail.com <mailto:renato.per...@gmail.com>> wrote:

        Is cassandra really supposed to have a static public IP for
        each and
        single node in the cluster?
        This seems to be expensive (static IPs are nor free neither
        cheap),
        still the broadcast_rpc_address expects a static IP for client
        communications (load balancing, contact points, etc.)
        Is there some mechanism to determine a public IP at runtime?

        Basically, I have nodes (machines) with dynamic public IPs
        and I cannot
        embed them in the cassandra.yaml file because of their
        dynamic nature
        (they change at each reboot).
        Any solution to this?

        Thanks.



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