[CASSANDRA-13079] Warn user to run full repair when increasing replication factor

• Type: Improvement
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 4.0-alpha1, 4.0
• Component/s: Legacy/Core

Environment

Debian

• Assignee: Marcus Eriksson
• Reporter: Vovodroid

Authors

Marcus Eriksson

Reviewers

Paulo Motta

• Created: 24/Dec/16 14:20
• Updated: 15/May/20 08:04
• Resolved: 20/Feb/17 12:53

Description

Scenario:
Start two nodes cluster.

Create keyspace with rep.factor one:
CREATE KEYSPACE rep WITH replication =

{'class': 'SimpleStrategy', 'replication_factor': 1}

;
CREATE TABLE rep.data (str text PRIMARY KEY );
INSERT INTO rep.data (str) VALUES ( 'qwerty');

Run nodetool flush on all nodes. On one of them table files are created.

Change replication factor to two:
ALTER KEYSPACE rep WITH replication =

{'class': 'SimpleStrategy', 'replication_factor': 2}

;

Run repair, then nodetool flush on all nodes. On all nodes table files are created.

Change replication factor to one:
ALTER KEYSPACE rep WITH replication =

{'class': 'SimpleStrategy', 'replication_factor': 1}

;

Then nodetool cleanup, only on initial node remained data files.

Change replication factor to two again:
ALTER KEYSPACE rep WITH replication =

{'class': 'SimpleStrategy', 'replication_factor': 2}

;

Run repair, then nodetool flush on all nodes. No data files on second node (though expected, as after first repair/flush).