[CASSANDRA-19768] nodetool assassinate of a CMS voting member should be allowed and should remove it from the CMS group

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 5.1
• Component/s: Transactional Cluster Metadata
• Bug Category: Correctness - API / Semantic Implementation
• Severity: Normal
• Complexity: Low Hanging Fruit
• Discovered By: Fuzz Test
• Platform: All
• Since Version: 5.1-alpha1

Source Control Link

https://github.com/apache/cassandra/commit/e5973bf34f7f61347f7e5d6aaafad3ed38f2f8b7

Test and Documentation Plan

ci run

• Assignee: Marcus Eriksson
• Reporter: David Capwell

Authors

Marcus Eriksson

Reviewers

Sam Tunnicliffe

• Created: 12/Jul/24 00:18
• Updated: 04/Sep/24 16:26
• Resolved: 28/Aug/24 06:45

Description

nodetool assassinate is a dangerous command but is needed when the node to be removed really can’t be accessed anymore (such as host failures). But when the node to be removed is a member of CMS, we block this action with the following error

Can not commit transformation: "INVALID"(Rejecting this plan as the node NodeId{id=3} is still a part of CMS.).

If the node in question is not up, and we call nodetool assassinate, we should then try to remove that node from the CMS membership group

Steps to repo

• Start 4 node cluster
• nodetool cms reconfigure 3
• targetNode = <one of the nodes in CMS>
• stop targetNode
• nodetool assassinate targetNode

Issue Links

• is related to: CASSANDRA-19847 Create a fuzz test that randomizes topology changes, cluster actions, and CQL operations
• links to: GitHub Pull Request #3448