example_latency_steadystate.fio

# Example FIO job file demonstrating latency steady state detection
# This example shows how to use FIO's latency steady state detection
# to automatically terminate workloads when latency stabilizes
#
# Based on SNIA SSD Performance Test Specification requirements:
# - Steady state is achieved when latency measurements don't change more than
#   20% for 5 measurement windows and remain within 5% of a line with 10% slope
# - This example uses more conservative 5% deviation threshold for demonstration

[global]
# Basic I/O parameters
ioengine=libaio
iodepth=32
bs=4k
direct=1
rw=randread
numjobs=1
time_based=1
runtime=3600  # Max runtime: 1 hour (will terminate early if steady state reached)

# Steady state detection parameters
steadystate=lat:5%           # Stop when latency mean deviation < 5% of average
steadystate_duration=300     # Use 5-minute rolling window for measurements
steadystate_ramp_time=60     # Wait 1 minute before starting measurements
steadystate_check_interval=10 # Take measurements every 10 seconds

# Output options
write_lat_log=lat_steadystate
log_avg_msec=10000           # Log average latency every 10 seconds

[latency_steady_test]
filename=/dev/nvme3n1
size=10G

# Alternative steady state configurations (uncomment to try):

# Use slope-based detection instead of deviation:
# steadystate=lat_slope:0.1%

# More aggressive detection (faster convergence):
# steadystate=lat:2%
# steadystate_duration=120    # 2-minute window
# steadystate_check_interval=5 # Check every 5 seconds

# More conservative detection (slower convergence):
# steadystate=lat:10%
# steadystate_duration=600    # 10-minute window