You’re free to supply your own Seed Provider. The Seed provider that comes with cassandra needs hard coded IPs, but there’s no reason why it has to be that way.
There’s a handful of ideas here: https://issues.apache.org/jira/browse/CASSANDRA-12627 <https://issues.apache.org/jira/browse/CASSANDRA-12627> Feel free to experiment, and good luck. > On May 2, 2017, at 6:48 PM, Roman Naumenko <ro...@sproutling.com> wrote: > > Service discovery (aka "note some IPs") should be part of the cluster > bootstrapping and management. > > See for example how elastic is doing this. Or consul. Its pretty standard > practice these days. > > -- > Roman > > On Tue, May 2, 2017 at 5:08 PM Steve Robenalt <sroben...@highwire.org > <mailto:sroben...@highwire.org>> wrote: > Hi Roman, > > I'm assuming you were intending your first statement to be in jest, but it's > really not that hard to startup a Cassandra cluster. The defaults are pretty > usable, so if all you want to do is set the IPs and start it up, the cluster > probably will just take care of everything else. > > So I jest a little bit too. It's normally desirable to set up storage > properly for your database, and there's a few options for which you might > want to change the defaults, such as the snitch. > > Still, if that means you only need to take note of of a couple of IPs and > designate them as seeds so your cluster can mostly manage itself, you can say > that's sad, but I'd say it's a small price to pay for all that you don't have > to do. > > Steve > > On Mon, May 1, 2017 at 4:55 PM, Roman Naumenko <ro...@sproutling.com > <mailto:ro...@sproutling.com>> wrote: > Lol yeah, why > I guess I run some ec2 instances, drop some cassandra deb packages on 'em - > the thing will figure out how to run... > > Also, how would you get "initial state of the cluster" if the cluster... is > being initialized? > Or that's easy, according to the docs - just hardcode some seed IPs into each > node, lol > > It's all kinda funny, but in a sad way. > > On Mon, May 1, 2017 at 4:45 PM, Jon Haddad <jonathan.had...@gmail.com > <mailto:jonathan.had...@gmail.com>> wrote: > Why do you have to figure out what’s up w/ them by accident? You’ve gotten > all the information you need. Seeds are used to get the initial state of the > cluster and as an optimization to spread gossip faster. That’s it. > > > >> On May 1, 2017, at 4:37 PM, Roman Naumenko <ro...@sproutling.com >> <mailto:ro...@sproutling.com>> wrote: >> >> Well, I guess I have to figure out what’s up with IPs/hostnames by >> experiment. >> Information about service discovery is practically absent. >> Not to mention all important details about fqdns/hostnames, automatic >> replacing seed nodes or what not. >> >> — >> Roman >> >>> On May 1, 2017, at 4:14 PM, Jon Haddad <jonathan.had...@gmail.com >>> <mailto:jonathan.had...@gmail.com>> wrote: >>> >>> The in-tree docs do not mention this anywhere, and even have some of the >>> answers you’re asking: >>> >>> https://cassandra.apache.org/doc/latest/faq/index.html?highlight=seed#what-are-seeds >>> >>> <https://cassandra.apache.org/doc/latest/faq/index.html?highlight=seed#what-are-seeds> >>> >>> The DataStax docs are maintained outside of the project, you’ll have to ask >>> them why they’re wrong or misleading. >>> >>> Jon >>> >>>> On May 1, 2017, at 4:10 PM, Roman Naumenko <ro...@sproutling.com >>>> <mailto:ro...@sproutling.com>> wrote: >>>> >>>> The docs mention IP addresses everywhere. >>>> >>>> http://docs.datastax.com/en/archived/cassandra/2.0/cassandra/operations/ops_replace_seed_node.html >>>> >>>> <http://docs.datastax.com/en/archived/cassandra/2.0/cassandra/operations/ops_replace_seed_node.html> >>>> Promote an existing node to a seed node by adding its IP address to -seeds >>>> list and remove (demote) the IP address of the dead seed node from the >>>> cassandra.yaml file for each node in the cluster. >>>> >>>> http://docs.datastax.com/en/archived/cassandra/2.0/cassandra/operations/ops_replace_node_t.html >>>> >>>> <http://docs.datastax.com/en/archived/cassandra/2.0/cassandra/operations/ops_replace_node_t.html> >>>> Note the Address of the dead node; it is used in step 5. >>>> >>>> http://docs.datastax.com/en/cassandra/2.1/cassandra/initialize/initializeSingleDS.html >>>> >>>> <http://docs.datastax.com/en/cassandra/2.1/cassandra/initialize/initializeSingleDS.html> >>>>> Properties to set: >>>>> num_tokens: recommended value: 256 >>>>> -seeds: internal IP address of each seed node >>>> >>>> I saw also hostnames mentioned few times, but it just makes it even more >>>> confusing. >>>> >>>> — >>>> Roman >>>> >>>>> On May 1, 2017, at 3:50 PM, Jon Haddad <jonathan.had...@gmail.com >>>>> <mailto:jonathan.had...@gmail.com>> wrote: >>>>> >>>>> Sure, you could use DNS. Where does it say IP addresses are a >>>>> requirement? >>>>> >>>>>> On May 1, 2017, at 1:36 PM, Roman Naumenko <ro...@sproutling.com >>>>>> <mailto:ro...@sproutling.com>> wrote: >>>>>> >>>>>> If I understand how Cassandra nodes work, they must contain a list of >>>>>> seed’s IP addressed in config file. >>>>>> >>>>>> This requirement makes cluster setup unnecessarily complicated. Is it >>>>>> possible to use DNS name for seed nodes? >>>>>> >>>>>> Thanks, >>>>>> >>>>>> — >>>>>> Roman >>>>>> --------------------------------------------------------------------- >>>>>> To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org >>>>>> <mailto:user-unsubscr...@cassandra.apache.org> >>>>>> For additional commands, e-mail: user-h...@cassandra.apache.org >>>>>> <mailto:user-h...@cassandra.apache.org> >>>>>> >>>>> >>>> >>> >> > > > > > > -- > Steve Robenalt > Software Architect, HighWire Press, Inc. > > www.highwire.org <http://www.highwire.org/>| Los Gatos, CA| Belfast, NI| > Brighton, UK > <https://www.linkedin.com/company-beta/1797/> > <http://twitter.com/highwirepress> > > HighWire Summer Publishers' Meeting, London, June 12-13 > <mailto:omenji...@highwire.org?subject=Please%20register%20me%20for%20HighWire%20Summer%20Publishers'%20Meeting%20in%20London!> > STM Annual US Conference, April 25-27: Michiel Klein Swormink and Jennifer > Chang are representing HighWire > <https://t.xink.io/Tracking/Index/XaoBAMZ_AAB-KCEA0> > 2017 CSE Annual Meeting: John Sack is presenting on topic of Piracy, May 23 > <https://t.xink.io/Tracking/Index/qKwBAMZ_AAB-KCEA0> > SSP Annual Meeting, May 31-June 2: Visit HighWire on Booth #101A > <https://t.xink.io/Tracking/Index/XaoBAMZ_AAB-KCEA0> > > > >
