[CASSANDRA-8513] SSTableScanner may not acquire reference, but will still release it when closed

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Duplicate
• Fix Version/s: 2.1.3
• Severity: Normal
• Assignee: Benedict Elliott Smith
• Reporter: Benedict Elliott Smith

Authors

Benedict Elliott Smith

Reviewers

Marcus Eriksson

• Created: 18/Dec/14 17:22
• Updated: 16/Apr/19 09:31
• Resolved: 05/Jan/15 14:33

Description

getRangeSlice and related methods do not require a reference to perform a safe read, so during one it is possible for SSTableScanner to fail to acquire a reference to the table it's being created on. In this case it doesn't fail, but it also doesn't log that no reference was acquired; on close, it still releases the reference that it never held.

We can fix this one of two ways: we can tell the scanner if we require a reference to be acquired; or we can track if one was obtained. The former is a bit more invasive but probably better, since we probably care if we fail to grab one in cases where we need it, and probably don't want to grab one otherwise.

Issue Links

• duplicates: CASSANDRA-8399 Reference Counter exception when dropping user type
• is related to: CASSANDRA-8399 Reference Counter exception when dropping user type
• is related to: CASSANDRA-7705 Safer Resource Management