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From Jack Krupansky <jack.krupan...@gmail.com>
Subject Re: electricity outage problem
Date Tue, 12 Jan 2016 16:42:22 GMT
Sometimes you may have to clear out the saved Gossip state:
https://docs.datastax.com/en/cassandra/2.0/cassandra/operations/ops_gossip_purge.html

Note the instruction about bringing up the seed nodes first. Normally seed
nodes are only relevant when initially joining a node to a cluster (and
then the Gossip state will be persisted locally), but if you clear te
persisted Gossip state the seed nodes will again be needed to find the rest
of the cluster.

I'm not sure whether a power outage is the same as stopping and restarting
an instance (AWS) in terms of whether the restarted instance retains its
current public IP address.



-- Jack Krupansky

On Tue, Jan 12, 2016 at 10:02 AM, daemeon reiydelle <daemeonr@gmail.com>
wrote:

> This happens when there is insufficient time for nodes coming up to join a
> network. It takes a few seconds for a node to come up, e.g. your seed node.
> If you tell a node to join a cluster you can get this scenario because of
> high network utilization as well. I wait 90 seconds after the first (i.e.
> my first seed) node comes up to start the next one. Any nodes that are
> seeds need some 60 seconds, so the additional 30 seconds is a buffer.
> Additional nodes each wait 60 seconds before joining (although this is a
> parallel tree for large clusters).
>
>
>
>
>
> *.......*
>
>
>
>
>
>
> *“Life should not be a journey to the grave with the intention of arriving
> safely in apretty and well preserved body, but rather to skid in broadside
> in a cloud of smoke,thoroughly used up, totally worn out, and loudly
> proclaiming “Wow! What a Ride!” - Hunter ThompsonDaemeon C.M. ReiydelleUSA
> (+1) 415.501.0198 <%28%2B1%29%20415.501.0198>London (+44) (0) 20 8144 9872
> <%28%2B44%29%20%280%29%2020%208144%209872>*
>
> On Tue, Jan 12, 2016 at 6:56 AM, Adil <adil.chabaq@gmail.com> wrote:
>
>> Hi,
>>
>> we have two DC with 5 nodes in each cluster, yesterday there was an
>> electricity outage causing all nodes down, we restart the clusters but when
>> we run nodetool status on DC1 it results that some nodes are DN, the
>> strange thing is that running the command from diffrent node in DC1 doesn't
>> give the same node in DC as own, we have noticed this message in the log
>> "received an invalid gossip generation for peer", does anyone know how to
>> resolve this problem? should we purge the gossip?
>>
>> thanks
>>
>> Adil
>>
>
>

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