Nodes

The nodes menu has two sub-menus in the navigation on the left and two tabs in the default view.

The node tree tab is the default view of the Management System. It displays all registered nodes in a node tree. It mainly serves an organizational purpose and does not impact the functionality of the nodes. Nodes and workloads can be managed in the node details view, which is reached through the node tree.

Selecting the node list tab displays a list of all available nodes that have been registered in the Management System. Add, remove, and edit nodes here.

Available updates for nodes can be found in the Updates sub-menu. Performed node updates can be viewed in the Update Log. When an update is performed, the update log also shows the current progress of the update.

Node tree

The node tree is the landing page of the Management System. It presents an overview of all nodes that are connected to the Management System, embedded into tree view elements. Being mainly a means of organization, it has no impact on the functionality of the nodes and their workloads. Select Nodes in the navigation on the left. Then select the node tree tab on the right.

There is only one element under the root after the initial setup: Root > Unassigned. All nodes that are registered in the Management System are placed in the Unassigned element by default. From there they can be moved to new elements that have to be created first.

Creating a new element in the node tree

Before moving a node out of the Unassigned element, create a new element in the node tree. Elements in the node tree exclusively serve an organizational purpose.

Select Nodes in the navigation on the left.
Select the node tree tab on the right.
Select the ellipsis menu to the right of Root in the node tree.
Select ADD in the overlay that popped up.
Enter the name of the new element in the field under Location.
Select Save.

The new element now appears under the Root element.

Create more elements and freely modify the node tree. To the right of every created element, there is an ellipsis menu that opens up an overlay. Add additional elements, edit the names of elements or delete the elements here.

Note

The order of the tree elements can be modified easily. Drag and drop an element to its new position.
When a tree element is deleted, all of the nodes inside the element will be moved to Unassigned.

Moving a node from one tree element to another

Moving nodes in the node tree is very straightforward and intuitive and possible by drag and drop. Make sure that a new tree element is created before attempting to move a node.

Select Nodes in the navigation on the left.
Select the node tree tab on the right.
Expand the tree element of the node that will be moved. The default element is Root > Unassigned.
Choose the node to move.
Drag and drop the node to the newly created element. Elements expand automatically once as they are hovered over.

The node has now been moved to the new element.

Note

A node cannot be moved back manually to Unassigned once it has been moved to another element.

Managing nodes in the node tree

Once nodes are registered in the Management System, view their details next to the node tree. To view the details of a node, select the node tree element.

Item	Description
Node name and serial (1)	Here the name and serial number of the node are shown. The serial number is next to the name in brackets.
Node version (2)	The version of the node depending on the product version of Nerve.
Device image (3)	An image of the hardware model is displayed here according to the device type that was selected when the node was added.
Node information (4)	Wan address This is the network address of the node that has been assigned by the DHCP server. Created This is the date when the node was added to the Management System. Last system start This is the timestamp of the last node restart in the format `DD/MM/YYYY, hh:mm:ss`. Labels Labels that are assigned to this node are listed here. Labels can be set in the Management System. Refer to Labels for more information.
Rebooting, deleting and remote connections (5)	Reboot node Selecting the reboot icon will reboot the node after a confirmation dialog. Select Yes to initiate the reboot. All running workloads will be stopped. After the reboot, the workloads will return to their previous state. Running workloads will be started. Stopped workloads will stay stopped. Delete node Selecting the garbage can icon removes the node from the Management System. The node needs to be registered again after removal. Connect Selecting the chain link icon opens an overlay, through which a remote connection to the node can be established. Refer to Remote Connections for more information.
Logs, metrics and more (6)	LOGS AND METRICS Select this to open an overlay that allows enabling of logging and monitoring, as well as viewing dashboards. Enable the following settings by toggling the button for each setting: SYSTEM MONITORING Toggle this slider to enable monitoring of the node's resource utilization as a whole. DOCKER WORKLOAD MONITORING Toggle this slider to enable gathering of metadata about installed Docker containers, as well as monitoring of their resource utilization. DOCKER WORKLOAD LOGGING Toggle this slider to enable the sending of application logs from Docker workloads on the node to the Management System. To open the dashboards, select the clickable links next to the sliders. For more detailed information, refer to Logging and monitoring. SYSTEM LOGS & SYSTEM LOG SETTINGS Selecting SYSTEM LOG will open a new window and show the system logs of the node. The internal node logs are aimed at Nerve service technicians in case of error and failure. Data is stored and visualized with OpenSearch. The amount of logs can be modified through the SYSTEM LOG SETTINGS by Nerve service technicians. Contact customer support for more information. VM VIDEO OPTION Note that this feature is only available on request. Configure the video output of Nerve Devices to directly output the interface of deployed virtual machines. Doing so allows operating virtual machines directly at the Nerve Device. Refer to Virtual machine video options for more information. CAPABILITIES The capabilities of each node are available as a list in both the Local UI and the Management System. A capability represents a specific feature or a set of features allowing the node to run workloads, to provide logs etc.
System metrics (7)	The system metrics that are available in the Local UI dashboard are also visible here: CPU The percentage here shows how much processing power is being used in total at the moment. This includes CPUs that have been assigned to VMs and Docker containers as well. Memory Similar to CPU usage, the percentage of memory used in total at the moment is shown here. This includes memory that has been assigned to VMs or Docker containers. Docker used space Two things are shown in this graph: The percentage shows how much of the available space for Docker containers is already used. The value shows the amount of space that is free. Docker containers have their dedicated virtual partition. VM used space Similar to Docker used space, two things are shown in this graph as well: The percentage shows how much of the available space for virtual machines is already used. The value shows the amount of free space. Note that deployed Virtual Machine workloads share a logical volume group with the Nerve Base System. Therefore the percentages and values displayed in this graph are in relation to the total amount of space available of the logical volume group.
Workloads overview (8)	Find workloads that have been deployed to the Nerve Device displayed here. The workloads can be displayed as tiles or as a list in a table. Table view gives the following information on workloads: Type The symbol of the workload type is displayed here. Name This is the name of the workload. Version This is the name of the workload version. Status The symbol here indicates the status of the workload. Here, different symbols can be shown: a green play symbol, a yellow pause symbol and a red stop symbol, showing whether a workload is running, suspended or stopped respectively. In addition, a triangular warning sign is displayed in an error state, and a gray dot is shown when the workload is idle. CPU This column shows values for VM and Docker workloads. The percentage here shows the usage of CPU resources in relation to the assigned CPUs. RAM Similar to the CPU usage statistic, the percentage here shows the usage of system memory resources in relation to the assigned memory. This column only shows values for Docker workloads. Deployed This is the date and time the workload was deployed in the format `DD/MM/YYYY, hh:mm::ss`. Last state change This is the date and time the workload changed from its previous state to its current state, for example when a running workload was stopped. The format is `DD/MM/YYYY, hh:mm::ss`. Selecting a workload leads to a control area in which the workload can be controlled. Workload control features depend on the workload type. If there are no tiles or rows of workloads, no workloads have been deployed to the Nerve Device. Refer to Workload control for more information.
Workload view selection (9)	Toggle between table view and tile view here.

Node capabilities

The capabilities of each node are available as a list in both the Local UI and the Management System. A capability represents a specific feature or a set of features allowing the node to run workloads, to provide logs etc. As of now most nodes share the same list of capabilities. In the future, with increasing modularity in the Nerve solution, the list will differ based on the specific Nerve solution running on the node.

Reach the list of node capabilities in the following locations:

Location	Path
Local UI	Log in to the Local UI. > Select Node configuration in the navigation on the left. > Select Capabilities.
Management System	Log in to the Management System > Select a node from the node tree. > Select CAPABILITIES.

Here is a list of all currently available capabilities:

Capability	Description
CODESYS PLC	The CODESYS application is installed in the RTVM and the execution of CODESYS workloads is possible.
Docker Container	Docker container technology is included and the node can run Docker workloads.
Logging via Filebeat	A daemon is running on the node that sends logs to the Management System.
Monitoring via Metricbeat	A daemon is running on the node that sends metric logs to the Management System.
Nerve Data Services	Nerve Data Services are available for nodes with this capability.
Virtualization via ACRN	The node is running on the ACRN hypervisor.
Virtualization via KVM	The node is running on the KVM hypervisor.
Virtualization via XEN	The node is running on the XEN hypervisor.

Node list

The topics covered in this chapter are mainly means of organization and have no impact on the functionality of the nodes and their workloads. Select Nodes in the navigation on the left. Then select the nodes tab on the right to display the list of registered nodes.

Note

Operational functions of the nodes are located in the node details view in the node tree.

Item	Description
Tab selection (1)	Switch between the node tree and the node list by selecting the appropriate tab.
Search bar (2)	Use the search bar to filter nodes by name.
Add new node (3)	Select the plus symbol to add a new node.
Name (4)	This is the name of the node. If a node is online or offline can be seen to the left of the name. Green indicates an online node while red shows an offline node. The sorting of the list can also be switched from alphabetical to reverse alphabetical by selecting Name, as well as being sorted by creation date by selecting Created.
Serial Number (5)	This is the serial number of the node that was defined during node configuration.
Node version (6)	This is the version of the node reflecting the version of the Nerve software.
Created (7)	This is the date the node was registered in the Management System in the format `DD/MM/YYYY, hh:mm:ss`. The list can be sorted by creation date when selecting Created.
Action (8)	This column contains icons representing actions. Selecting the Delete symbol here deletes the node, removing it from the Management System.

Adding a node

Nodes can only be added to the Management System if they have been configured in the Local UI, as the serial number and secure ID of the node are required. Refer to Node configuration before continuing.

Select Nodes in the menu on the left side.
Select the nodes tab on the right to display the list of registered nodes.
Select the plus symbol (Add new node) in the upper-right corner.

Enter the following information:

Item	Description
Name	Enter the name for the node that will make it easy to identify.
Secure ID	Enter the secure ID that is generated when the node is configured in the Local UI. Refer to Node configuration for more information.
Serial Number	Enter the serial number of the Nerve Device that was defined during node configuration.
Insert Label	This field is optional. Add labels to the node for easier identification and workload deployment. Note that labels have to be created first before they can be assigned to nodes. Refer to Labels for more information.
Nerve Device name	Select the Nerve Device, on which the node is hosted from the drop-down menu. The name is set to MFN 100 by default. A picture of the selected Nerve Device will be displayed in the node details. Refer to the device guide for more information on qualified Nerve Devices.

Select Save to save the changes.

The node now appears in the node list and in Root > Unassigned in the node tree and can be worked with. At first, the node is marked as offline. It can take up to a minute until the node is shown as online in the Management System. The Management System refreshes automatically.

Editing the details of nodes

After registering a node, edit its details in the Nodes menu. Use the search bar at the top to search for nodes if a large number of nodes is registered.

Select Nodes in the navigation on the left.
Select the nodes tab on the right to display the list of registered nodes.
Select a node from the list.

Edit the details of the node:

Item	Description
Name	Enter the name of the node.
Secure ID	This is the ID generated during the node registration process. Do not edit this ID without a valid reason.
Serial Number	This is the serial number of the node. Do not edit the serial number without a valid reason.
Timezone	This is the time zone of the node. This setting cannot be edited here. The time zone setting is set in the Local UI. Refer to Node configuration for more information.
Insert label	This field is optional. Add labels to the node for easier identification and workload deployment. Refer to Labels for more information.
Version	This is the node version. This field cannot be edited.
Device type	This is the device the node is hosted on. This field cannot be edited.
REMOTE CONNECTIONS	This is a list of remote connections to the node stating the NAME, TYPE, and PORT of available remote connections. Add or delete remote connections here. Refer to Remote Connections for more information.

Note

Changing the Secure ID or Serial Number of a node will break the connection between the node and the Management System.

Select Update to save the changes.

Updating a node to a new version

Nodes are updated through the Management System where currently available updates are listed. Note that nodes can only be updated in order, meaning that node versions cannot be skipped. When an update is started, a snapshot of the user data is made and running workloads are stopped. Reverting to the previous version is possible. Workloads remain stopped after an update or revert.

Note

By updating a node, the passwords to the Local UI and host access are reset if they have not been changed by the user. Local UI and host access passwords set by the user persist through updates.
Note that the update process described here is valid for nodes from version 2.1.0 and later. Nodes below version 2.1.0 need to be updated manually by installing an image at the Nerve Device. Refer to Manual image installation for more information.

Expand Nodes > Updates in the navigation on the left.
Select a node version from the list. Available nodes for the update to the selected version will appear on the right.
Tick the checkboxes next to the nodes that will be updated.
Select Update.
Select Yes in the pop-up window.

The Management System will display the log screen where the update is shown as in progress. The progress bar here shows the progress of the entire update campaign if more than one node has been selected before. Click the progress bar to see the progress of the update to each node.

Note

There are two possible error states in case the node update fails:

Fail
Support needs to take action. Contact TTTech Industrial customer support by writing an issue through the TTTech Industrial support portal.
Not Responding
In this case, attempt a physical reboot by unplugging the node from power and plugging it back in again. The node should come online with the new version installed. However, the update log will still show the update as In progress. Select the ellipsis menu in the update log and select MARK AS FINISHED to manually mark the node update as finished.

Removing a node

Note that generally there is no need in removing a node. Only remove a node in case of technical difficulties or by request of customer support. To remove a node, select the corresponding Delete icon in the Action column on the right side of the node list.