Your example only really applies if someone is using a 20 node cluster at
RF=1, something I've never seen, but I'm sure exists somewhere.
Realistically, RF=3 using racks (or AWS regions) and 21 nodes, means you'll
have 3 racks with 7 nodes per rack. Adding a single node is an unlikely
operation,
On Sat, 8 Sep 2018, 19:00 Jeff Jirsa, wrote:
> Virtual nodes accomplish two primary goals
>
> 1) it makes it easier to gradually add/remove capacity to your cluster by
> distributing the new host capacity around the ring in smaller increments
>
> 2) it increases the number of sources for
Thanks Jeff, You mean that with RF=2, num_tokens = 256 and having less than 256
nodes i should not worry about data distribution? Sent using Zoho Mail On
Sat, 08 Sep 2018 21:30:28 +0430 Jeff Jirsa wrote
Virtual nodes accomplish two primary goals 1) it makes it easier to gradually
Virtual nodes accomplish two primary goals
1) it makes it easier to gradually add/remove capacity to your cluster by
distributing the new host capacity around the ring in smaller increments
2) it increases the number of sources for streaming, which speeds up bootstrap
and decommission
Whether
> I wonder why not setting it to all the way down to 1 then? What's the key
difference once you have so few vnodes?
4 tokens lets you have balanced clusters when they're small and imposes
very little overhead when they get big. Using multiple tokens let's
multiple nodes stream data to the new
Keep using whatever settings you've been using. I'd still use allocate
tokens for keyspace but it probably won't make much of a difference with
256 tokens.
On Sat, Sep 8, 2018 at 10:40 AM onmstester onmstester
wrote:
> Thanks Jon,
> But i never concerned about num_tokens config before, because
On Sat, 8 Sep 2018, 14:47 Jonathan Haddad, wrote:
> 256 tokens is a pretty terrible default setting especially post 3.0. I
> recommend folks use 4 tokens for new clusters,
>
I wonder why not setting it to all the way down to 1 then? What's the key
difference once you have so few vnodes?
with
256 tokens is a pretty terrible default setting especially post 3.0. I
recommend folks use 4 tokens for new clusters, with some caveats.
When you fire up a cluster, there's no way to make the initial tokens be
distributed evenly, you'll get random ones. You'll want to set them
explicitly using:
Why not setting default vnodes count to that recommendation in Cassandra
installation files? Sent using Zoho Mail On Tue, 04 Sep 2018 17:35:54
+0430 Durity, Sean R wrote Longer term, I
agree with Oleksandr, the recommendation for number of vnodes is now much
smaller than 256. I
term, I agree with Oleksandr, the recommendation for number of vnodes is
now much smaller than 256. I am using 8 or 16.
Sean Durity
From: Oleksandr Shulgin
Sent: Monday, September 03, 2018 10:02 AM
To: User
Subject: [EXTERNAL] Re: adding multiple node to a cluster, cleanup and
num_tokens
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