Visualize a mixed-workload


I used my viz_workload tool to capture data while running a multi-node workload that featured mixed phases:

Here's the actual script:

# Simulate a workload with:
# - disk write 8GB to disk and sync
# - high cpu load on 4 threads
# - flush the disk cache to force disk read in next step
# - disk read 8GB from disk


cleanup () {
  rm -f "$TMP_FN"
  exit "$1"

trap 'cleanup 1' SIGTERM SIGINT # Cleanup tmp file if killed early

echo "Writing to disk"
dd if=/dev/random of="$TMP_FN" bs=1024k count=8192
sleep 2

echo "Loading CPU on 4 threads"
timeout 30 taskset -c 0 bash -c "while true; do true; done;" &
timeout 30 taskset -c 1 bash -c "while true; do true; done;" &
timeout 30 taskset -c 2 bash -c "while true; do true; done;" &
timeout 30 taskset -c 3 bash -c "while true; do true; done;" &
sleep 2

echo "Clearing disk cache prior to disk read"
echo 1 | sudo tee /proc/sys/vm/drop_caches

echo "Reading from disk"
dd if="$TMP_FN" of=/dev/null


I have 2 ~$200 servers running Ubuntu that I use for various things, like:

server name Architecture link
lynx Intel Amazon
moose AMD Mini's forum (discontinued model)


System snapshots

One of the cool things about this tool is how much data it captures about each node prior to running the workload.

System summary graphic

Check out the interactive pages for:

Workload data

You can clearly see the different phases (disk write, high CPU, disk read) of the workload in the graphs.

Mixed workload graphic

For moose:

The lynx performance is significantly faster iduring the IO portions, thanks to NVME on lynx vs standard HDD on moose. You can find this info from the system summary:

IO comparison.