Hi Nick,

I forgot to say I was using 1.2.3 which I think uses different ports. So I will upgrade to 1.4.1 and open those ports across the firewall although that's kind of a pain. I already have about 320 config lines for the Cassandra cluster itself.

So, just to make things clear, is it mandatory to have one OpsCenter instance per Cassandra cluster? Even if that cluster is split in multiple Cassandra DCs across separate regions?

Is there a way to have one OpsCenter per Cassandra DC (monitor Cassandra DCs individually)? That would get rid of many configuration issues!


On Thu, Mar 29, 2012 at 9:35 PM, Nick Bailey <nick@datastax.com> wrote:
This setup may be possible although there are a few potential issues.
Firstly, see: http://www.datastax.com/docs/opscenter/configure_opscenter#configuring-firewall-port-access

Basically the agents and OpsCenter communicate on ports 61620 and
61621 by default (those can be configured though). The agents will
contact the the OpsCenter machine on port 61620. You can specify the
interface the agents will use to connect to this port when
installing/setting up the agents.

The OpsCenter machine will contact the agents on port 61621. Right now
the OpsCenter machine will only talk to the nodes using the
listen_address configured in your cassandra conf. We have a task to
fix this in the future so that you can configure the interface that
opscenter will contact each agent on. In the meantime though OpsCenter
will need to be able to hit the listen_address for each node.

On Thu, Mar 29, 2012 at 12:47 PM, Alexandru Sicoe <adsicoe@gmail.com> wrote:
> Hello,
>  I am planning on testing OpsCenter to see how it can monitor a multi DC
> cluster. There are 2 DCs each on a different side of a firewall. I've
> configured NAT on the firewall to allow the communication between all
> Cassandra nodes on ports 7000, 7199 and 9160. The cluster works fine.
> However when I start OpsCenter (obviously on one side of the firewall) the
> OpsCenter CF gives me two schema versions in the cluster and basically
> messes up everything. Plus, I can only see the nodes on one the same side.
> What are the requirements to let the OpsCenter on one side see the Cassandra
> nodes and the OpsCenter agents on the other, and viceversa?
> Is it possible to use OpsCenter across a firewall?
> Cheers,
> Alex