[CASSANDRA-13701] Lower default num_tokens

• Type: Improvement
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 4.0-beta4, 4.0
• Component/s: Local/Config
• Complexity: Normal

Source Control Link

https://github.com/apache/cassandra/commit/3cfc8502b82ba88da6ffc69fdad476f7fa0819ca https://github.com/apache/cassandra-builds/commit/6ff05f088ccab9a2376d2b83f9ef66a800b0c787

Test and Documentation Plan

Associated documentation about num_tokens is in https://cassandra.apache.org/doc/latest/getting_started/production.html#tokens as part of CASSANDRA-15618 as well as upgrading information in NEWS.txt.

• Assignee: Alexander Dejanovski
• Reporter: Chris Lohfink

Authors

Alexander Dejanovski

Reviewers

Brandon Williams, Michael Semb Wever

• Created: 19/Jul/17 23:13
• Updated: 01/Jun/22 06:41
• Resolved: 17/Dec/20 21:37

Description

For reasons highlighted in CASSANDRA-7032, the high number of vnodes is not necessary. It is very expensive for operations processes and scanning. Its come up a lot and its pretty standard and known now to always reduce the num_tokens within the community. We should just lower the defaults.

Issue Links

• Blocked: CASSANDRA-13348 Duplicate tokens after bootstrap
• causes: CASSANDRA-16364 Joining nodes simultaneously with auto_bootstrap:false can cause token collision
• is duplicated by: CASSANDRA-14784 Evaluate defaults in cassandra.yaml for 4.0
• is duplicated by: CASSANDRA-15521 Update default for num_tokens from 256 to something more reasonable
• relates to: CASSANDRA-16979 DOC - num_tokens default shown as 256 but is 16 starting in 4.0
• relates to: CASSANDRA-16079 Improve dtest runtime
• links to: GitHub Pull Request #132