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From Jai Bheemsen Rao Dhanwada <jaibheem...@gmail.com>
Subject Re: Cassandra write path during the decommissioning process
Date Mon, 29 Jun 2020 21:23:12 GMT
Thank you

On Mon, Jun 29, 2020 at 1:01 PM Jeff Jirsa <jjirsa@gmail.com> wrote:

> When range movements happen (bootstrap and decom are the same here), the
> reads go to the existing replicas, and the writes go to both existing and
> the gaining replicas.
>
> This is because the decom (or bootstrap, or move) may fail at any time, so
> you need to make sure the consistency contract is maintained whether the
> range movement succeeds or fails.
>
> Quorum calculations are adjusted to accommodate this - for example, if you
> have RF=3, and you add a new host , the RF = 3 (existing) + 1 (pending),
> quorum becomes 3 of 4.
>
> On Mon, Jun 29, 2020 at 12:48 PM Jai Bheemsen Rao Dhanwada <
> jaibheemsen@gmail.com> wrote:
>
>> Can someone please share thoughts on this?
>>
>> On Wed, Jun 24, 2020 at 4:25 PM Jai Bheemsen Rao Dhanwada <
>> jaibheemsen@gmail.com> wrote:
>>
>>> Hello,
>>>
>>> I would like to understand how the writes happen when there is a node in
>>> the cluster that is being decommissioned.
>>>
>>> During the decommission process, the node will send the streams to the
>>> rest of the nodes that it owns. what happened to the read and write of the
>>> data that is owned by the node that is being decommissioned? does it even
>>> receive reads and writes or the nodes doesn't receive any writes?
>>>
>>>
>>>

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