I see no reason to restart all nodes. You can continue to use seed from
first DC - seed used for loading ring configuration(locations, token
ranges, etc), not data.
On 05/17/2013 10:34 AM, Sergey Naumov wrote:
If I understand you correctly, GossipingPropertyFileSnitch is useful
for manipulations with nodes within a single DC, but to add a new DC
without having to restart every node in all DCs (because seeds are
specified in cassandra.yaml and I need to restart a node after
addition of a new seed from newly created DC), I anyway have to use
cassandra-topology.properties and edit it on every node of a cluster.
By the way, it it necessary to specify seeds if I use
PropertyFileSnitch and there is info in cassandra-topology.properties
about all nodes of a cluster?
Yes, it is. Cassandra need seed(s), because topology properties have no
info about token ranges.
2013/5/17 aaron morton <aa...@thelastpickle.com
<mailto:aa...@thelastpickle.com>>
You should configure the seeds as recommended regardless of the
snitch used.
You need to update the yaml file to start using the
GossipingPropertyFileSnitch but after that it reads the
cassandra-rackdc.properties file to get information about the
node. It reads uses the information in gossip to get information
about the other nodes in the cluster.
If there is no info in gossip about a remote node, because say it
has not been upgraded, it will fall back to using
cassandra-topology.properties.
Hope that helps.
-----------------
Aaron Morton
Freelance Cassandra Consultant
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 15/05/2013, at 8:10 PM, Sergey Naumov <sknau...@gmail.com
<mailto:sknau...@gmail.com>> wrote:
> As far as I understand, GossipingPropertyFileSnitch supposed to
provide more flexibility in nodes addition/removal. But what about
addition of a DC? In datastax documentation
(http://www.datastax.com/docs/1.2/operations/add_replace_nodes#add-dc)
it is said that cassandra-topology.properties could be updated
without restart for PropertyFileSnitch. But here
(http://www.datastax.com/docs/1.0/initialize/cluster_init_multi_dc) it
it said, that "you MUST include at least one node from EACH data
center. It is a best practice to have at more than one seed node
per data center and the seed list should be the same for each
node". At the first glance it seems that PropertyFileSnitch will
get necessary info from cassandra-topology.properties, but for
GossipingPropertyFileSnitch modification of cassandra.yaml and
restart of all nodes in all DCs will be required. Could somebody
clarify this topic?
>
> Thanks in advance,
> Sergey Naumov.
