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Subject: Clarification on num_tokens setting
From: Baron Schwartz <baron@xaprb.com>
To: user@cassandra.apache.org
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As I understand the num_tokens setting, it makes Cassandra do the following
pseudocode when a new node is added:

for 1...num_tokens do
   my_token = rand(0, 2^128-1)
   next_token = min(tokens in cluster where token > my_token)
   my_range = (my_token, next_token - 1)
done

Now the new node owns num_tokens chunks of keys that previously belonged to
other nodes.

My point is, with 1 node in the cluster, the ring is divided into
num_tokens ranges. With N nodes, the ring is divided into N*num_tokens.
Correct? The docs do not make this clear for me.

And another point: the tokens are randomly chosen, so the ranges of keys
are not uniform, although with enough nodes in the cluster there probably
won't be any really large ranges. Correct?

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<div dir=3D"ltr">As I understand the num_tokens setting, it makes Cassandra=
 do the following pseudocode when a new node is added:<div><br></div><div s=
tyle>for 1...num_tokens do</div><div style>=A0 =A0my_token =3D rand(0, 2^12=
8-1)</div>
<div style>=A0 =A0next_token =3D min(tokens in cluster where token &gt; my_=
token)</div><div style>=A0 =A0my_range =3D (my_token, next_token - 1)</div>=
<div style>done</div><div style><br></div><div style>Now the new node owns =
num_tokens chunks of keys that previously belonged to other nodes.</div>
<div style><br></div><div style>My point is, with 1 node in the cluster, th=
e ring is divided into num_tokens ranges. With N nodes, the ring is divided=
 into N*num_tokens. Correct? The docs do not make this clear for me.</div>
<div style><br></div><div style>And another point: the tokens are randomly =
chosen, so the ranges of keys are not uniform, although with enough nodes i=
n the cluster there probably won&#39;t be any really large ranges. Correct?=
</div>
</div>

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