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Posted to user@cassandra.apache.org by Roman Naumenko <ro...@sproutling.com> on 2017/05/01 20:36:51 UTC

Service discovery in the Cassandra cluster

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
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Re: Service discovery in the Cassandra cluster

Posted by daemeon reiydelle <da...@gmail.com>.
Yes, you can use host names. That merely adds another level of
configuration. When using terraform, I often use node names like
<mumble><nth node> and just use those. They are only routable within the
region/VPC but are in fact already in dns. You do have to watch out as if
you change the seeds (in tf) or the cluster can get terminated and rebuild.
If you have a way to capture these (you can do it in ansible, I had been
told it is really hard to do in Chef/Puppet) then your cms can just adjust
the xml as needed without fussing with route53.


*.......*



*Daemeon C.M. ReiydelleUSA (+1) 415.501.0198London (+44) (0) 20 8144 9872*

On Mon, May 1, 2017 at 3:50 PM, Jon Haddad <jo...@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> 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-unsubscribe@cassandra.apache.org
> > For additional commands, e-mail: user-help@cassandra.apache.org
> >
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: user-unsubscribe@cassandra.apache.org
> For additional commands, e-mail: user-help@cassandra.apache.org
>
>

Re: Service discovery in the Cassandra cluster

Posted by daemeon reiydelle <da...@gmail.com>.
My compliments to all of you for being adults, excessively kind, and
definitely excessively nice.


*.......*



*Daemeon C.M. ReiydelleUSA (+1) 415.501.0198London (+44) (0) 20 8144 9872*

On Tue, May 2, 2017 at 5:08 PM, Steve Robenalt <sr...@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>
> 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 <jo...@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> 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 <jo...@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?highl
>>> ight=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> wrote:
>>>
>>> The docs mention IP addresses everywhere.
>>>
>>> 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
>>> Note the Address of the dead node; it is used in step 5.
>>>
>>> http://docs.datastax.com/en/cassandra/2.1/cassandra/initiali
>>> ze/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 <jo...@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> 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-unsubscribe@cassandra.apache.org
>>> For additional commands, e-mail: user-help@cassandra.apache.org
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>
>
> --
>
>
> * Steve Robenalt Software Architect, HighWire Press, Inc. *
> 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
> <omenjivar@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>
>
>
>
>

Re: Service discovery in the Cassandra cluster

Posted by Jon Haddad <jo...@gmail.com>.
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 <srobenalt@highwire.org <ma...@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 <roman@sproutling.com <ma...@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.haddad@gmail.com <ma...@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 <roman@sproutling.com <ma...@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.haddad@gmail.com <ma...@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 <roman@sproutling.com <ma...@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.haddad@gmail.com <ma...@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 <roman@sproutling.com <ma...@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-unsubscribe@cassandra.apache.org <ma...@cassandra.apache.org>
>>>>>> For additional commands, e-mail: user-help@cassandra.apache.org <ma...@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:omenjivar@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>
> 
> 
>  
> 


Re: Service discovery in the Cassandra cluster

Posted by Roman Naumenko <ro...@sproutling.com>.
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 <sr...@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>
> 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 <jo...@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> 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 <jo...@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
>>>
>>> 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> wrote:
>>>
>>> The docs mention IP addresses everywhere.
>>>
>>>
>>> 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
>>> 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
>>>
>>> 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 <jo...@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> 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-unsubscribe@cassandra.apache.org
>>> For additional commands, e-mail: user-help@cassandra.apache.org
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>
>
> --
>
>
> * Steve Robenalt Software Architect, HighWire Press, Inc. *
> 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
> <omenjivar@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>
>
>
>
>

Re: Service discovery in the Cassandra cluster

Posted by Steve Robenalt <sr...@highwire.org>.
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> 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 <jo...@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> 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 <jo...@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?highl
>> ight=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> wrote:
>>
>> The docs mention IP addresses everywhere.
>>
>> 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
>> Note the Address of the dead node; it is used in step 5.
>>
>> http://docs.datastax.com/en/cassandra/2.1/cassandra/initiali
>> ze/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 <jo...@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> 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-unsubscribe@cassandra.apache.org
>> For additional commands, e-mail: user-help@cassandra.apache.org
>>
>>
>>
>>
>>
>>
>>
>


-- 


* Steve Robenalt Software Architect, HighWire Press, Inc. *
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
<omenjivar@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>

Re: Service discovery in the Cassandra cluster

Posted by Roman Naumenko <ro...@sproutling.com>.
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 <jo...@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> 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 <jo...@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
>
> 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> wrote:
>
> The docs mention IP addresses everywhere.
>
> 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
> 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
>
> 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 <jo...@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> 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-unsubscribe@cassandra.apache.org
> For additional commands, e-mail: user-help@cassandra.apache.org
>
>
>
>
>
>
>

Re: Service discovery in the Cassandra cluster

Posted by Jon Haddad <jo...@gmail.com>.
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> 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.haddad@gmail.com <ma...@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 <roman@sproutling.com <ma...@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.haddad@gmail.com <ma...@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 <roman@sproutling.com <ma...@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-unsubscribe@cassandra.apache.org <ma...@cassandra.apache.org>
>>>>> For additional commands, e-mail: user-help@cassandra.apache.org <ma...@cassandra.apache.org>
>>>>> 
>>>> 
>>> 
>> 
> 


Re: Service discovery in the Cassandra cluster

Posted by Roman Naumenko <ro...@sproutling.com>.
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 <jo...@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 <roman@sproutling.com <ma...@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.haddad@gmail.com <ma...@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 <roman@sproutling.com <ma...@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-unsubscribe@cassandra.apache.org <ma...@cassandra.apache.org>
>>>> For additional commands, e-mail: user-help@cassandra.apache.org <ma...@cassandra.apache.org>
>>>> 
>>> 
>> 
> 


Re: Service discovery in the Cassandra cluster

Posted by Jon Haddad <jo...@gmail.com>.
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> 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.haddad@gmail.com <ma...@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 <roman@sproutling.com <ma...@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-unsubscribe@cassandra.apache.org <ma...@cassandra.apache.org>
>>> For additional commands, e-mail: user-help@cassandra.apache.org <ma...@cassandra.apache.org>
>>> 
>> 
> 


Re: Service discovery in the Cassandra cluster

Posted by Roman Naumenko <ro...@sproutling.com>.
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 <jo...@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> 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-unsubscribe@cassandra.apache.org
>> For additional commands, e-mail: user-help@cassandra.apache.org
>> 
> 


Re: Service discovery in the Cassandra cluster

Posted by Jon Haddad <jo...@gmail.com>.
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> 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-unsubscribe@cassandra.apache.org
> For additional commands, e-mail: user-help@cassandra.apache.org
> 


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