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From "Nick Bailey (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CASSANDRA-8338) Simplify Token Selection
Date Mon, 24 Nov 2014 19:29:13 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-8338?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14223366#comment-14223366
] 

Nick Bailey commented on CASSANDRA-8338:
----------------------------------------

It might be worth putting this in a different file than cassandra.yaml. It's already confusing
that some options in there (initial_token, num_tokens) only matter the very first time a node
starts up. I'm not sure if we should be adding more. Also we should make sure we convey that
this only helps when the entire cluster is being set up for the first time, not when adding
nodes.

Lastly, this will need to incorporate rack information as well if we want it to work correctly
when not everything is in the same rack.

> Simplify Token Selection
> ------------------------
>
>                 Key: CASSANDRA-8338
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8338
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Config
>            Reporter: Joaquin Casares
>            Assignee: Jeremiah Jordan
>            Priority: Trivial
>              Labels: lhf
>
> When creating provisioning scripts, especially when running tools like Chef, each node
is launched individually. When not using vnodes your initial setup will always be unbalanced
unless you handle token assignment within your scripts. 
> I spoke to someone recently who was using this in production and his operations team
wasn't too pleased that they had to use OpsCenter as an extra step for rebalancing. Instead,
we should provide this functionality out of the box for new clusters.
> Instead, could we have the following options below the initial_token section?
> {CODE}
> # datacenter_index: 0
> # node_index: 0
> # datacenter_size: 1
> {CODE}
> The above configuration options, when uncommented, would do the math of:
> {CODE}
> token = node_index * (range / datacenter_size) + (datacenter_index * 1000000) + start_of_range
> {CODE}
> This means that users don't have to repeatedly implement the initial_token selection
code nor know the range and offsets of their partitioner.



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