[CASSANDRA-5161] Slow secondary index performance when using VNodes

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Duplicate
• Component/s: Feature/2i Index
• Severity: Normal
• Assignee: Unassigned
• Reporter: Steeve Morin
• Created: 15/Jan/13 16:28
• Updated: 16/Apr/19 09:32
• Resolved: 18/Jan/13 00:26

Description

When having a big number of vnodes (such as 256/node advised by http://www.datastax.com/dev/blog/upgrading-an-existing-cluster-to-vnodes), using secondary indices becomes really slow because Cassandra has to search for the index in all the nodes.

This results in very slow queries (in the order of 1-2s).

For an exemple, see this tracing with a 3 physical nodes cluster with 256 vnodes on each.
The keyspace has a RF=3.

https://gist.github.com/16f510fc349584966a56