Re: Does node add/remove requires all cluster nodes be present?

[Jinhua Luo]

Could you explain more?

When we add a new node, it should migrate data from other nodes, right?
What happens if other nodes are absent? For example, the cluster
consists of 3 nodes, but 2 nodes down, now we add the fourth new node,
what happens then?

2018-05-01 12:01 GMT+08:00 Jeff Jirsa :
> nodetool decommission streams data from the losing replica, so only that 
> instance has to be online (and decom should be preferred to removenode)
>
> If that instance is offline, you can use removenode, but you risk violating 
> consistency guarantees
>
> Adding nodes is similar - bootstrap streams from the losing range
>
> --
> Jeff Jirsa
>
>
>> On Apr 30, 2018, at 8:57 PM, Jinhua Luo  wrote:
>>
>> Hi All,
>>
>> When a new node added, due to the even distribution of the new tokens,
>> the current nodes of the ring should migrate data to this new node.
>>
>> So, does it requires all nodes be present? If not, then if some nodes
>> are down, then it will miss the data migration of those parts, how and
>> when to fix it? When those nodes come back?
>>
>> Similarly, the node removal would migrate its data to other nodes, so
>> it seems that all other nodes must be present, otherwise it would lost
>> data?
>>
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>
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Re: Does node add/remove requires all cluster nodes be present?

[Jeff Jirsa]

nodetool decommission streams data from the losing replica, so only that 
instance has to be online (and decom should be preferred to removenode)

If that instance is offline, you can use removenode, but you risk violating 
consistency guarantees

Adding nodes is similar - bootstrap streams from the losing range

-- 
Jeff Jirsa


> On Apr 30, 2018, at 8:57 PM, Jinhua Luo  wrote:
> 
> Hi All,
> 
> When a new node added, due to the even distribution of the new tokens,
> the current nodes of the ring should migrate data to this new node.
> 
> So, does it requires all nodes be present? If not, then if some nodes
> are down, then it will miss the data migration of those parts, how and
> when to fix it? When those nodes come back?
> 
> Similarly, the node removal would migrate its data to other nodes, so
> it seems that all other nodes must be present, otherwise it would lost
> data?
> 
> -
> To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org
> For additional commands, e-mail: user-h...@cassandra.apache.org
> 

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