Component Status

For each component, BOS tracks information on what actions are expected to be happening (the phase) and what actions have recently happened (the last_action). This information is then aggregated into an overall status.

Phases

A component’s phase is the high level part of the boot process that the component is currently on. This value is automatically monitored and set by the status operator based on the components desired and current state in BOS, the components power state as reported by HSM, and the component’s configuration status as reported by CFS. Session status is also aggregated by phase in order to show a high level view of where components are at in the boot process. For more on session status see BOS session status.

The possible values for this field are:

  • powering_on

    A component will be in the powering_on phase whenever its current power state is off, and it has a desired state.

  • powering_off

    A component will be in the powering_off phase whenever its current power state is on, and it has a desired state that does not match the current state (a reboot operation) or when the desired state is empty (a shutdown operation).

  • configuring

    A component will be in the configuring phase whenever its current power state is on, its desired and current state match, and when CFS does not yet report that configuration is complete for the component with the desired configuration set in BOS.

  • None

    An empty phase indicates that the component is in a stable state and that BOS is not currently taking actions on the component.

Last actions

The last_action field stores information on the last action that was taken by BOS for this component. This field is automatically updated by the operators as they take actions. For more information on the BOS operators see BOS operators.

The possible values for this field are:

  • powering_on

    This indicates that the power-on operator called PCS to power-on the component.

  • powering_off_gracefully

    This indicates that the power-off-graceful operator called PCS to gracefully power-off the component.

  • powering_off_forcefully

    This indicates that the power-off-forceful operator called PCS to gracefully power-off the component.

  • apply_staged

    This indicates that the applystaged endpoint was called for this component and that the staged state was moved to the desired state. This is the only action that is reported by the API rather than an operator.

  • session_setup

    This indicates that the session-setup operator set this component’s desired state based on a new session.

  • newly_discovered

    This indicates that the component was recently added to the BOS database by the discovery operator.

Status

The status field is aggregated from information stored in the phase, last_action and an optional status_override field, which is used to store additional information when BOS would not normally have internal access to the data it needs to determine the status. status provides detailed information on where the component is in the boot process, and is used by the BOS operators to determine which components they should be acting on.

The possible values for this field are:

  • power_on_pending

    This indicates that the component needs to be powered on, but PCS has not yet been called. This status will be set when the phase is powering_on and the last_action is not powering_on. The power-on operator monitors for components in this state to find components that need to be acted on.

  • power_on_called

    This indicates that PCS has been called to power on the component, but HSM does not yet report that the component is on. This status will be set when the phase is powering_on and the last_action is powering_on The component will remain in this state until HSM reports the component is on and ready. If the max_power_on_wait_time expires while waiting for the component to power on, the status reverts to power_on_pending. If the max_boot_wait_time expires while waiting for the component to become ready, the status reverts to power_off_pending, and the component is rebooted. See Options for more on max_power_on_wait_time and max_boot_wait_time.

  • power_off_pending

    This indicates that the component needs to be powered off, but PCS has not yet been called. This status will be set when the phase is powering_off and the last_action is not powering_off_gracefully or powering_off_forcefully. The power-off-graceful operator monitors for components in this state to find components that need to be acted on.

  • power_off_gracefully_called

    This indicates that PCS has been called to power off the component, but HSM does not yet report that the component is off. This status will be set when the phase is powering_off and the last_action is powering_off_gracefully The component will remain in this state until either HSM reports the power state for the component is off and the status operator updates the phase, or until the max_power_off_wait_time has expired and the power-off-forceful operator takes over. See Options for more on max_power_off_wait_time.

  • power_off_forcefully_called

      This indicates that PCS has been called to power off the component, but HSM does not yet report that the component is off.

    This status will be set when the phase is powering_off and the last_action is powering_off_gracefully The component will remain in this state until either HSM reports the power state for the component is off and the status operator updates the phase, or until the max_power_off_wait_time has expired and the power-off-forceful operator takes over. See Options for more on max_power_off_wait_time.

  • configuring

    This indicates that the component is booted with the correct boot artifacts, but that CFS is reporting the component still has pending configuration. This status will be set when the phase is configuring and either the desired configuration in CFS does not match what BOS believes the configuration should be, or configuration for the component is not yet complete.

  • stable

    This indicates that the component is in the desired state. This status will be set when the phase is not set.

  • failed

    This indicates that the component is not yet in the desired state, but that BOS will not take further actions on the component. This can be due to too many attempts of a power action, or due to CFS reporting failed configuration.

  • on_hold

    This indicates that something has changed about the components state, such as re-enabling a component in BOS, and that BOS needs to gather information from other services and re-evaluate the state of the node. This is done so that none of the BOS operators take action against a node based on stale information in the BOS database.

Status transitions

The possible transitions between statuses are show below. As actions are being taken against a node, it flows through the power action and configuration statuses, from pending to called and then on to the next action’s status. Components will start and end with in the stable state or failed state, and when something changes to the component it will re-enter the flow at one of the pending statuses.

on_hold is a special case, and any status can flow into or out of the status, depending on what actions cause BOS to re-evaluate, and where it finds the component once the evaluation is complete. However, typically on_hold will be the result of a stable of failed component being re-enabled, and will flow into on of the pending statuses.

Status Transitions

For more information on the BOS operators that act on components to move them from state to state, see BOS operators