Basic Terminology¶
The following definitions describe key concepts and terminology that are commonly used in the StarlingX community and in this documentation.
- All-in-one Controller Node¶
A single physical node that provides a controller function, worker function, and storage function.
- All-in-one Simplex (optimized) restore¶
Optimized restore indicates that the restore is done using restore_mode=optimized set. This is mandatory and applies only for AIO-SX (optimized) restore deployments.
- Bare Metal¶
A node running without Kubelet or hypervisors (for example, application workloads run directly on the operating system which runs directly on the hardware).
- Controller¶
A node within a StarlingX edge cloud that runs the cloud management software (control plane). There can be either one or two controller nodes in a StarlingX edge cloud.
Runs cloud control functions for managing cloud resources.
Runs all Kubernetes control functions such as kube-apiserver, kube-controller-manager and kube-schedule
Runs all OpenStack control functions, such as managing images, virtual volumes, virtual network, and virtual machines.
Can be part of a two-node HA control node cluster for running control functions either active/active or active/standby.
- CRUSH¶
The CRUSH algorithm computes storage locations in order to determine how to store and retrieve data. CRUSH allows Ceph clients to communicate with OSDs directly rather than through a centralized server or broker. By using an algorithmically-determined method of storing and retrieving data, Ceph avoids a single point of failure, a performance bottleneck, and a physical limit to its scalability.
- CSM Observability¶
An OpenTelemetry agent that collects array-level metrics for Dell storage.
- Data Network(s)¶
Networks attached to pci-passthrough and/or sriov interfaces that are made available to hosted containers or hosted VMs for pci-passthrough and/or SR-IOV interfaces.
Networks attached to data interfaces of the OpenStack vSwitch, on which the OpenStack / Neutron provider networks are realized and become the VM tenant networks.
Only worker-type and all-in-one-type nodes, which host end-user containers and/or VMs would have data network(s) attached.
In the case of openstack-compute labelled worker nodes, a data network MUST be attached to at lease one ‘data’ (vSwitch) interface.
- Deployment Tools¶
Tools that make the process of distributing, installing, and managing updates.
- Downgrade¶
The process of moving from a higher version or a newer release of a software, firmware, or operating system to a lower version or an older release.
- Edge Computing¶
The delivery of computing capabilities to the logical extremes of a network in order to improve the performance, operating cost and reliability of applications and services. By shortening the distance between devices and the resources that serve them, and also reducing network hops, edge computing mitigates the latency and bandwidth constraints of today’s Internet, ushering in new classes of applications.
- Elliptic Curve Digital Signature Algorithm (ECDSA)¶
ECDSA is an asymmetric key encryption algorithm that uses Elliptic curve cryptography to produce keys and sign data.
- Infra Network¶
A deprecated optional network that was historically used for access to the storage cluster.
If this optional network is used, all node types are required to be connected to the INFRA network.
- IoT (Internet of Things)¶
A system of computing devices that can operate with little/no human interaction.
- IPMI Network¶
An optional network on which IPMI interfaces of all nodes are connected. The network must be reachable using L3/IP from the controller’s OAM interfaces.
You can optionally connect all node types to the IPMI network.
- Kubernetes Cluster¶
A set of machines that has a common control plane for running orchestrated applications.
- Management Network¶
A private network (that is, not connected externally), typically 10GE, used for the following:
Internal StarlingX Infrastructure management monitoring and control
in the case of openstack, it is also used by VM I/O access to virtualized disks in Ceph Storage Cluster
All nodes are required to be connected to the management network.
- Multi-host (legacy) restore¶
Legacy restore indicates that the restore is done without using
restore_mode=optimized. Legacy restore is mandatory for multi-host systems like AIO-DX or Standard.- Node¶
A computer that is usually a server-class system.
- Node Interfaces¶
All nodes’ network interfaces can, in general, optionally be either:
Untagged single port.
Untagged two-port LAG and optionally split between redundant L2 switches running vPC (Virtual Port-Channel), also known as multichassis EtherChannel (MEC).
VLAN on either single-port ETH interface or two-port LAG interface.
- OAM Network¶
The network on which all external StarlingX platform APIs are exposed, (that is, REST APIs, Horizon web server, SSH, and SNMP), typically 1GE.
Only controller type nodes are required to be connected to the OAM network.
- Precheck¶
A system state checks intended to confirm the system health for an impending operation. This check can be performed at any time prior to the system operation execution, but is intended to be executed just prior to confirming that it can be scheduled before actually attempting the operation.
- Preinstallation¶
New deployments for a system that is installed in the factory. Preinstallation also refers to software media that is installed alongside the existing deployment in preparation for an upgrade.
- Prestaging¶
System software media is prepopulated on the system in preparation for an impending operation. Prestaging is currently supported for installation and upgrade operation.
- Prometheus¶
An open source software application that is used to monitor and alert events. For more information, see https://prometheus.io/.
- PXE Boot Network¶
An IPv4 network over which nodes netboot from controllers.
The node’s interface to the PXE Boot Network MUST be untagged and on the same physical interface as where the node’s Management Network interface is configured. If the node’s Management Network interface is configured untagged on a physical interface, then the node’s interface to the PXE Boot Network does NOT need to be explicitly configured.
However, if the node’s Management Network interface is configured on a tagged VLAN interface, then the node’s interface to the PXE Boot Network needs to be EXPLICITLY configured.
The node’s Management Network interface is recommended to be configured on a tagged VLAN, in the following cases:
If the Management Network MUST be IPv6, it is recommended to configure the node’s interface to the Management Network on tagged vlan. This avoids potential complications with multiplexing an IPv4 PXE Boot Network and an IPv6 Management Network on the same L2 network.
If the Management Network needs to be dual-stack (IPv4 and IPv6) and IPv6 is selected as the primary address pool family (see IPv4/IPv6 Dual-Stack Network). Again this avoids potential complications with multiplexing an IPv4 PXE Boot Network and a dual-stack Management Network on the same L2 network.
- Restore¶
Bringing back a system or data from a backup or a previously saved state. For StarlingX, Restore can be used for current release (N) or (N-1).
- Rollback¶
The process of reverting changes made to a system or database to a previous state. For StarlingX, Rollback is a capability that is supported during an upgrade or update.
A single physical port that can be shared by two or more system networks (oam, mgmt., cluster-host, pxeboot and data) For more information, see SRIOV Port Sharing.
- StarlingX¶
StarlingX is an open source, complete cloud infrastructure software stack for the edge used by the most demanding applications in industrial IoT, telecom, and other use cases. The platform creates a fusion between OpenStack and Kubernetes to provide a robust and flexible environment for all kinds of workloads, including containerized, virtualized or bare metal.
- Storage¶
A node within a StarlingX edge cloud that is dedicated to providing file and object storage to application workloads. There can be 0 or more storage nodes within a StarlingX edge cloud.
Runs CEPH distributed storage software.
Part of an HA multi-node CEPH storage cluster supporting a replication factor of two or three, journal caching, and class tiering.
Provides HA persistent storage for images, virtual volumes (that is, block storage), and object storage.
- Unity XT¶
A simple, fast, flexible, and all-inclusive unified storage platform.
- Virtual Machines (VM)¶
An instance of a node provided by software (a hypervisor), which runs within the host operating system and hardware.
- Virtualization¶
The act of creating a virtual version of CPU, network or storage device.
- Worker¶
A node within a StarlingX edge cloud that is dedicated to running application workloads. There can be 0 to 99 worker nodes in a StarlingX edge cloud.
In a configuration running OpenStack, a worker node:
is labeled as ‘compute’
may be referred to as a compute node.
runs virtual switch for realizing virtual networks.
provides L3 routing and NET services.
