Haven't tried this by myself, but I suspect that in order to add public
addresses for existing nodes for inter-dc communication, following method might
work (just my guess):
- take a node, shutdown C* there, change it's private IP, add public IP,
update cassandra.yaml accordingly (the same way as you described +set new
private IP) and replace 'old node' as described here:
http://docs.datastax.com/en/archived/cassandra/2.2/cassandra/operations/opsReplaceNode.html
- do the same for the rest of nodes, one by one.
But it's better to test this approach somewhere in sandbox.
Also, AFAIK, only *listen* parameters have influence on how C* builds its ring.
*rpc* settings are for communications b/w clients and Cassandra.
Regards,
Kyrill
Replacing a dead node or dead seed
node<http://docs.datastax.com/en/archived/cassandra/2.2/cassandra/operations/opsReplaceNode.html>
docs.datastax.com
Steps to replace a node that has died for some reason, such as hardware failure.
From: Thomas Goossens <tho...@drillster.com>
Sent: Friday, January 19, 2018 2:18:14 PM
To: user@cassandra.apache.org
Subject: Unable to change IP address from private to public
Hello,
For an 8-node Cassandra 2.2.11 cluster which is spread over two datacenters, I
am looking to change from using private IP addresses to the combination of
private and public IP addresses and interfaces. The cluster uses the
GossipingPropertyFileSnitch.
The aim is to end up with each peer being known by their public IP address, but
communicating over the private network where possible. We are looking to make
this change in rolling fashion, so without taking down the entire cluster.
To this end, I have made the following configuration changes:
1. cassandra-rackdc.properties: add the "prefer_local=true" option
2. cassandra.yaml:
- change the broadcast_address from the private address to the public address
- add "listen_on_broadcast_address: true"
- leave the "listen_address" to be the private IP address
- change the broadcast_rpc_address from the private address to the public
address
3. infrastructure:
- amend firewall settings to allow TCP traffic between peers on all interfaces
for the relevant ports
Upon trying to make the described changes on a non-seed node, the following
happens:
- The node appears to start up normally
- Upon running nodetool status on the changed node, all peers appear to be
down, except the local node:
Datacenter: DC-A
=
DN 10.x.x.x
DN 10.x.x.x
DN 10.x.x.x
DN 10.x.x.x
DN 10.x.x.x
Datacenter: DC-B
=
DN 10.x.x.x
DN 10.x.x.x
UN 123.x.x.x
- Upon running nodetool status on any other node, all peers appear to be up,
except the changed node which is still known under its old IP address:
Datacenter: DC-A
=
UN 10.x.x.x
UN 10.x.x.x
UN 10.x.x.x
UN 10.x.x.x
UN 10.x.x.x
Datacenter: DC-B
=
UN 10.x.x.x
UN 10.x.x.x
DN 10.x.x.x
Reverting the changes in cassandra.yaml and restarting that node causes the
cluster to go back to normal. I have tried various combinations of
private/public IP address settings, all to no avail.
I have successfully set up a similar configuration in a test cluster, but I
have had to bring down the entire cluster in order to get it to work.
My question is: is it possible to make such a change in a phased way without
bringing down the entire cluster? If yes, what is the best approach?
Many thanks in advance.
Thomas
--
Thomas Goossens
CTO
[Drillster]
Rijnzathe 16
3454 PV De Meern
Netherlands
+31 88 375 0500<tel:+31%2088%20375%200500>
www.drillster.com<http://www.drillster.com/>
