[CASSANDRA-5692] Race condition in detecting version on a mixed 1.1/1.2 cluster

• Type: Bug
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 1.2.7, 2.0 beta 1
• Severity: Low
• Assignee: Sergio Bossa
• Reporter: Sergio Bossa

Authors

Sergio Bossa

Reviewers

Jason Brown

• Created: 23/Jun/13 12:57
• Updated: 16/Apr/19 09:32
• Resolved: 27/Jun/13 20:40

Description

On a mixed 1.1 / 1.2 cluster, starting 1.2 nodes fires sometimes a race condition in version detection, where the 1.2 node wrongly detects version 6 for a 1.1 node.

It works as follows:
1) The just started 1.2 node quickly opens an OutboundTcpConnection toward a 1.1 node before receiving any messages from the latter.
2) Given the version is correctly detected only when the first message is received, the version is momentarily set at 6.
3) This opens an OutboundTcpConnection from 1.2 to 1.1 at version 6, which gets stuck in the connect() method.

Later, the version is correctly fixed, but all outbound connections from 1.2 to 1.1 are stuck at this point.

Evidence from 1.2 logs:
TRACE 13:48:31,133 Assuming current protocol version for /127.0.0.2
DEBUG 13:48:37,837 Setting version 5 for /127.0.0.2