Queue schedulers play a critical role in
disk I/O performance. A Linux migration or upgrade can change the previously configured
queue scheduler and should be checked after the migration or upgrade. See Verify queue scheduler settings for more
information.
Table 1. | Queue scheduler | Description |
|---|
| noop | Best for SSDs or other devices where seek time is irrelevant.
Provides FIFO (First In, First Out) queueing. |
| mq-deadline | Best for SSDs or NVMe storage. A multi-queue (mq) version of the
deadline scheduler. Provides a balance between performance and fairness
and ensures that I/O requests are processed within a specific time
frame. |
| cfq | Generally not recommended for high-throughput systems. Completely
fair queuing (cfq) prioritizes fairness over performance. |
Table 2. Cassandra-specific queue scheduler
recommendations| Queue scheduler | Storage device | Notes |
|---|
| noop | SSDs | SSDs do not benefit from seek optimizations. Provides FIFO reducing
overhead. |
| mq-deadline | HDDs or mixed environments | Balances fairness and performance. Best choice when lower latency is
critical. |
