[CASSANDRA-11502] Fix denseness and column metadata updates coming from Thrift

• Type: Bug
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 2.2.7, 3.0.6, 3.6
• Component/s: Legacy/Distributed Metadata
• Severity: Low
• Since Version: 2.0.10
• Assignee: Aleksey Yeschenko
• Reporter: Aleksey Yeschenko

Authors

Aleksey Yeschenko

Reviewers

Sylvain Lebresne

• Created: 05/Apr/16 16:45
• Updated: 16/Apr/19 09:30
• Resolved: 27/Apr/16 17:01

Description

It was decided that we'd be recalculating is_dense for table updates coming from Thrift on every change. However, due to some oversight, is_dense can only go from false to true. Once dense, even adding a REGULAR column will not reset is_dense back to false.

The recalculation fails because no matter what happens, we never remove the auto-generated CLUSTERING and COMPACT_VALUE columns of a dense table.

Which ultimately leads to the issue on 2.2 to 3.0 upgrade (see CASSANDRA-11315).

What we should do is remove the special-case for Thrift in LegacySchemaTables::makeUpdateTableMutation and correct the logic in ThriftConversion::internalFromThrift to remove those columns when going from dense to sparse.

This is not enough to fix CASSANDRA-11315, however, as we need to handle pre-patch upgrades, and upgrades from 2.1. Fixing it in 2.2 means a) getting proper schema from DESCRIBE now and b) using the more efficient SparseCellNameType when you add columns.

Issue Links

• is related to: CASSANDRA-11315 Fix upgrading sparse tables that are incorrectly marked as dense