> I had seed nodes ip1,ip2,ip3 as the seeds but what I didn't realize was then
> that these nodes had themselves as seeds. I am assuming that should never be
> done, is that correct.
The only reason nodes listing them selves as seeds can be a pain is during
bootstrap. Seeds nodes will not stream data to themselves.
> QUESTION: Would it be ok if I just configured every node to be the 3 ip's
> after it like this instead as well
It's generally accepted to list the same 3 nodes from each DC on all nodes.
> So, the most secure way is to write all your other nodes as seed,
This may have a small impact on gossip. Gossip rounds go to a live node, a down
node with some probability and a seed node with some probability.
/* Gossip with the seed with some probability. */
double probability = seeds.size() / (double)(
liveEndpoints.size() + unreachableEndpoints.size() );
double randDbl = random.nextDouble();
if ( randDbl <= probability )
sendGossip(prod, seeds);
If you have every node a seed it looks like you would always gossip to a seed.
Cheers
-----------------
Aaron Morton
Freelance Cassandra Consultant
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 25/06/2013, at 2:43 AM, julien Campan <[email protected]> wrote:
> Hi ,
>
> The seeds are only used when a node appears in the cluster. At this moment it
> chooses a seed (in the same dc) in order to have some information.
>
> So, the most secure way is to write all your other nodes as seed, but in fact
> you need only one up.
> if you think that you will never have 3 node down at the same time , you can
> put only three nodes.
>
>
> Julien Campan
>
>
> 2013/6/24 Hiller, Dean <[email protected]>
> For ease of use, we actually had a single cassandra.yaml deployed to every
> machine and a script that swapped out the token and listen address. I had
> seed nodes ip1,ip2,ip3 as the seeds but what I didn't realize was then that
> these nodes had themselves as seeds. I am assuming that should never be
> done, is that correct. I really should deploy ip1, ip2, ip3 on all nodes and
> then for nodes 1, 2, and 3, I should do something like
>
> ip1 will have ip2, ip3, ip4
> ip2 will have ip1, ip3, ip4
> Etc. etc.
>
> QUESTION: Would it be ok if I just configured every node to be the 3 ip's
> after it like this instead as well
> ip1 would have ip2, ip3, ip4
> ip2 would have ip3, ip4, ip5
> ip3 would have ip4, ip5, ip6
> ip4 would have ip5, ip6, ip1
>
> Is this okay for seed node configuration?
>
> Thanks,
> Dean
>
>
