Hardware Burn-in

Overview

Workflows to onboard new hardware often include a stress-testing step to provoke early failures and to avoid that these load-triggered issues only occur when the nodes have already moved to production. These burn-in tests typically include CPU, memory, disk, and network. With the Xena release, Ironic supports such tests as part of the cleaning framework.

The burn-in steps rely on standard tools such as stress-ng for CPU and memory, or fio for disk and network. The burn-in cleaning steps are part of the generic hardware manager in the Ironic Python Agent (IPA) and therefore the agent ramdisk does not need to be bundled with a specific IPA hardware manager to have them available.

Each burn-in step accepts (or in the case of network: needs) some basic configuration options, mostly to limit the duration of the test and to specify the amount of resources to be used. The options are set on a node’s driver-info and prefixed with agent_burnin_. The options available for the individual tests will be outlined below.

CPU burn-in

The options, following a agent_burnin_ + stress-ng stressor (cpu) + stress-ng option schema, are:

  • agent_burnin_cpu_timeout (default: 24 hours)

  • agent_burnin_cpu_cpu (default: 0, meaning all CPUs)

to limit the overall runtime and to pick the number of CPUs to stress.

For instance, in order to limit the time of the CPU burn-in to 10 minutes do:

baremetal node set --driver-info agent_burnin_cpu_timeout=600 \
    $NODE_NAME_OR_UUID

Then launch the test with:

baremetal node clean --clean-steps '[{"step": "burnin_cpu", \
    "interface": "deploy"}]' $NODE_NAME_OR_UUID

Memory burn-in

The options, following a agent_burnin_ + stress-ng stressor (vm) + stress-ng option schema, are:

  • agent_burnin_vm_timeout (default: 24 hours)

  • agent_burnin_vm_vm-bytes (default: 98%)

to limit the overall runtime and to set the fraction of RAM to stress.

For instance, in order to limit the time of the memory burn-in to 1 hour and the amount of RAM to be used to 75% run:

baremetal node set --driver-info agent_burnin_vm_timeout=3600 \
    $NODE_NAME_OR_UUID
baremetal node set --driver-info agent_burnin_vm_vm-bytes=75 \
    $NODE_NAME_OR_UUID

Then launch the test with:

baremetal node clean --clean-steps '[{"step": "burnin_memory", \
    "interface": "deploy"}]' $NODE_NAME_OR_UUID

Disk burn-in

The options, following a agent_burnin_ + fio stressor (fio_disk) + fio option schema, are:

  • agent_burnin_fio_disk_runtime (default: 0, meaning no time limit)

  • agent_burnin_fio_disk_loops (default: 4)

to set the time limit and the number of iterations when going over the disks.

For instance, in order to limit the number of loops to 2 set:

baremetal node set --driver-info agent_burnin_fio_disk_loops=2 \
    $NODE_NAME_OR_UUID

Then launch the test with:

baremetal node clean --clean-steps '[{"step": "burnin_disk", \
    "interface": "deploy"}]' $NODE_NAME_OR_UUID

Network burn-in

Burning in the network needs a little more config, since we need a pair of nodes to perform the test. Therefore, this test needs to set agent_burnin_fio_network_config JSON which requires a role field (values: reader, writer) and a partner field (value is the hostname of the other node to test), like:

baremetal node set --driver-info agent_burnin_fio_network_config= \
    '{"role": "writer", "partner": "$HOST2"}' $NODE_NAME_OR_UUID1
baremetal node set --driver-info agent_burnin_fio_network_config= \
    '{"role": "reader", "partner": "$HOST1"}' $NODE_NAME_OR_UUID2

In addition and similar to the other tests, there is a runtime option to be set (only on the writer):

baremetal node set --driver-info agent_burnin_fio_network_runtime=600 \
    $NODE_NAME_OR_UUID

Then launch the test with:

baremetal node clean --clean-steps '[{"step": "burnin_network",\
    "interface": "deploy"}]' $NODE_NAME_OR_UUID1
baremetal node clean --clean-steps '[{"step": "burnin_network",\
    "interface": "deploy"}]' $NODE_NAME_OR_UUID2

Both nodes will wait for the other node to show up and block while waiting. If the partner does not show up, the cleaning timeout will step in.

Additional Information

All tests can be aborted at any moment with

baremetal node abort $NODE_NAME_OR_UUID

One can also launch multiple tests which will be run in sequence, e.g.:

baremetal node clean --clean-steps '[{"step": "burnin_cpu",\
   "interface": "deploy"}, {"step": "burnin_memory",\
   "interface": "deploy"}]' $NODE_NAME_OR_UUID

If desired, configuring fast-track may be helpful here as it allows to keep the node up between consecutive calls of baremetal node clean.