[CASSANDRA-3245] Don't fail when numactl is installed, but NUMA policies are not supported

• Type: Bug
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 1.0.0
• Component/s: Packaging

Environment

Any Linux system where a 'numactl' executable is available, but no NUMA policies are actually supported. EC2 nodes are easy examples of environments with no NUMA policy support.

• Severity: Low
• Assignee: Peter Schuller
• Reporter: paul cannon

Authors

Peter Schuller

Reviewers

paul cannon

• Created: 23/Sep/11 02:56
• Updated: 16/Apr/19 09:32
• Resolved: 26/Sep/11 20:47

Description

When numactl is installed but NUMA policies are not supported, trying to run cassandra gives only:

numactl: This system does not support NUMA policy

..and the startup script fails there.

We should probably fail a little more gracefully. Possibly the best way to tell if numactl will work is by using:

numactl --hardware

but I don't have ready access to a machine with proper NUMA support at the moment so I can't check how easy it is to tell the difference in the output.

It looks just as reliable (if possibly a bit more brittle) to check for the existence of the directory /sys/devices/system/node. If that directory doesn't exist, we shouldn't even try to use or run numactl.