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From Jonathan Lacefield <>
Subject Re: Adding new node to cluster
Date Wed, 18 Feb 2015 13:48:59 GMT

  Please note that DataStax has updated the documentation for replacing a
seed node.  The new docs outline a simplified process to help avoid the
confusion on this topic.


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Jonathan Lacefield

Solution Architect | (404) 822 3487 |

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On Tue, Feb 17, 2015 at 8:04 PM, Robert Coli <> wrote:

> On Tue, Feb 17, 2015 at 2:25 PM, <> wrote:
>>  SimpleSnitch is not rack aware. You would want to choose seed nodes and
>> then not change them. Seed nodes apparently don’t bootstrap.
> No one seems to know what a "seed node" actually *is*, but "seed nodes"
> can in fact bootstrap. They just have to temporarily forget to tell
> themselves that they are a seed node while bootstrapping, and then other
> nodes will still gossip to it as a seed once it comes up, even though it
> doesn't consider itself a seed.
> "
> Replacing a seed node is a very common operation, and this best practice
> is confusing/poorly documented. There are regular contacts to
> #cassandra/cassandra-user@ where people ask how to replace a seed node,
> and are confused by the answer. The workaround also means that, if you do
> not restart your node after bootstrapping it (and changing the conf file
> back to indicate to itself that it is a seed) the node runs until next
> restart without any understanding that it is a seed node.
> Being a seed node appears to mean two things :
> 1) I have myself as an entry in my own seed list, so I know that I am a
> seed.
> 2) Other nodes have me in their seed list, so they consider me a seed.
> The current code checks for 1) and refuses to bootstrap. The workaround is
> to remove the 1) state temporarily. But if it is unsafe to bootstrap a seed
> node because of either 1) or 2), the workaround is unsafe.
> Can you explicate the special cases here? I sincerely would like to
> understand why the code tries to prevent "a seed" from bootstrapping when
> one can clearly, and apparently safely, bootstrap "a seed".
> "
> Unfortunately, there has been no answer.
> =Rob

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