SDP Controller Device

Introduction

The SDP controller Tango device is designed to provide the overall control and monitoring of the SDP. Its attributes report on the overall state of the system.

The present implementation of the SDP controller device does the following:

• performs the state transitions in response to commands

• reports the version of the SDP and its components

• reports the status of SDP components

• reports the health state of the system based on the component status

Commands

The commands change the device state as described below, but at present they have no other effect on SDP.

Command	Argument type	Return type	Action
On	None	None	Set device state to ON
Standby	None	None	Set device state to STANDBY
Off	None	None	Set device state to OFF

Attributes

Device attributes:

Attribute	Type	Read/Write	Values	Description
versionId	String	Read	Semantic version	Controller device server version
sdpVersion	String (JSON)	Read	SDP version information	Versions of the SDP and its components
adminMode	Enum	Read/Write	Admin mode values	SDP admin mode
healthState	Enum	Read	Health state values	SDP health state
components	String (JSON)	Read	Components attribute	Reports information on SDP components

Events

The controller device generates both change events and archive events for the following attributes:

• State

• versionId

• sdpVersion

• adminMode

• healthState

• components

SDP version information

This attribute contains information about the versions of the SDP and its components, formatted as a JSON string. The following is an example of the version information as provided by the SDP Helm chart.

{
    "version": "0.18.0",
    "components": {
        "etcd": {
            "image": "artefact.skao.int/ska-sdp-etcd"
            "version": "3.5.9"
        },
        "lmc-controller": {
            "devicename": "test-sdp/controller/0",
            "image": "artefact.skao.int/ska-sdp-lmc",
            "version": "0.25.0"
        },
        "lmc-subarray-01": {
            "devicename": "test-sdp/subarray/01",
            "image": "artefact.skao.int/ska-sdp-lmc",
            "version": "0.25.0"
        },
        "lmc-queueconnector-01": {
            "devicename": "test-sdp/queueconnector/01",
            "image": "artefact.skao.int/ska-sdp-lmc-queue-connector",
            "version": "3.0.1"
        },
        "dsconfig": {
            "image": "artefact.skao.int/ska-tango-images-tango-dsconfig",
            "version": "1.5.12"
        },
        "proccontrol": {
            "image": "artefact.skao.int/ska-sdp-proccontrol",
            "version": "0.12.2"
        },
        "helmdeploy": {
            "image": "artefact.skao.int/ska-sdp-helmdeploy",
            "version": "0.14.1"
        },
        "console": {
            "image": "artefact.skao.int/ska-sdp-console",
            "version": "0.5.1"
        }
    },
    "dependencies": {
        "kafka": {
            "repository": "https://charts.bitnami.com/bitnami",
            "version": "23.0.1"
        },
        "ska-sdp-qa": {
            "repository": "https://artefact.skao.int/repository/helm-internal",
            "version": "0.23.2"
        },
        "ska-tango-base": {
            "repository": "https://artefact.skao.int/repository/helm-internal",
            "version": "0.4.7"
        }
    }
}

Admin mode values

The admin mode is a writeable attribute which is used to indicate the intended use of the SDP.

adminMode	Description
ONLINE (0)	SDP can be used for normal operations
OFFLINE (1)	SDP should not be used
ENGINEERING (2)	SDP can be used for engineering purposes such as testing, debugging or commissioning
NOT_FITTED (3)	Treated as OFFLINE
RESERVED (4)	Treated as OFFLINE

Some of these values are not applicable to a software-only system like the SDP, but they are implemented for compatibility with the standard interface.

If the admin mode is set to OFFLINE, NOT_FITTED or RESERVED the device state is set to DISABLE, but there are no other changes to the behaviour of the system.

Health state values

healthState	Description
OK (0)	SDP is functioning as expected
DEGRADED (1)	SDP can only provide part of its functionality
FAILED (2)	SDP is unable to function
UNKNOWN (3)	Controller device is unable to determine the health of the SDP

The health state is based on the status of the SDP components:

• if all components are online: health state is OK

• if the Helm Deployer or the Processing Controller is offline: health state is DEGRADED

• if any of the subarrays are offline: health state is DEGRADED

• if all subarrays are offline: health state is FAILED

Components attribute

Reports various information on components in the form of a JSON string. Currently, it contains status information of the:

• Subarray device(s)

• Processing Controller

• Helm Deployer

When queried, it checks that each component is online i.e. that it is reported as being “alive” in the configuration database.

Example string:

{
    "lmc-controller": {"status": "ONLINE"},
    "lmc-subarray-01": {"status": "ONLINE"},
    "lmc-subarray-02": {"status": "OFFLINE",
                        "error": {"SDP Subarray is OFFLINE. It cannot be used for processing."}
                        },
    "proccontrol": {"status": "ONLINE"},
    "helmdeploy": {"status": "OFFLINE",
                   "error": "SDP Helm Deployer is OFFLINE:
                            - Cannot deploy new processing scripts.
                            - Running scripts will not deploy execution engines.
                            - Deployments are not cleaned up."}
                  }
}