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From "Aleksey Yeschenko (JIRA)" <>
Subject [jira] [Commented] (CASSANDRA-9227) Support num_tokens: 0
Date Thu, 23 Apr 2015 15:26:38 GMT


Aleksey Yeschenko commented on CASSANDRA-9227:

[~rbranson] Brandon mentioned that CASSANDRA-6961 already kinda gets us there (and there is
a comment by you there, too).

Did that patch turn out to not be enough? Can you elaborate a bit on what's missing?

> Support num_tokens: 0
> ---------------------
>                 Key: CASSANDRA-9227
>                 URL:
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Rick Branson
> num_tokens: 0 would allow serving proxy traffic on non-storage machines. Token-aware
routing does improve the cost of proxying a bit, but it only works in cases where CL<=1
for reads, and doesn't really improve the write situation. For some installations, token-aware
routing is also impractical, such as when there are a very large number of clients.
> For use cases that are throughput-bound rather than storage-bound, this would allow running
CPU-intensive proxy work on cheaper "diskless" machines. Proxies could also be installed on
the same machine as the client or on separate "edge" machines that are closer to the client
than the storage nodes. In my observation, anywhere between 25-50% of a node's CPU is spent
on proxy work, depending on the workload.
> I say "diskless" because they can't be truly diskless as they would have to store hints.
Hint storage can use cheap spinning disks or small solid-state drives instead of expensive
big disk arrays or big SSDs.

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