[CASSANDRA-14504] fqltool should open chronicle queue read only and a GC bug

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 4.0-alpha1, 4.0
• Component/s: Legacy/Tools
• Labels: fqltool
• Severity: Normal
• Assignee: Ariel Weisberg
• Reporter: Ariel Weisberg

Authors

Ariel Weisberg

Reviewers

Sam Tunnicliffe

• Created: 07/Jun/18 17:42
• Updated: 15/May/20 08:02
• Resolved: 18/Jun/18 16:53

Description

There are two issues with fqltool.

The first is that it doesn't open the chronicle queue read only so it won't work if it doesn't have write permissions and it's not clear if it's safe to open the queue to write if the server is also still appending.

The next issue is that NativeBytesStore.toTemporaryDirectByteBuffer() returns a ByteBuffer that doesn't strongly reference the memory it refers to resulting it in sometimes being reclaimed and containing the wrong data when we go to read from it. At least that is the theory. Simple solution is to use toByteArray() and that seems to make it work consistently.