Applicazioni#
The Applications page lists the applications installed in the cluster.
The list can be filtered by:
Type, for example to list only Nextcloud applications.Node, to limit the list to applications installed on a specific cluster node.Free text, to display only applications matching a certain string.
A single click on the application name opens its configuration page.
A click on the application type shows detailed information about the application itself. This information, including the version, is also available from the Software center page.
Each item in the list has a three-dots menu with the available actions for that application.
Installed applications are also listed in the application drawer, by
clicking the 
menu in the top-right corner of the screen. The
drawer shows only installed applications, not those available for
installation.
The application name#
Every time an application is added to the cluster, it is uniquely
identified by its name followed by a sequential number. Given the
application Myapp, installed instances will be named myapp1,
myapp2 and so on.
This internal, unique identifier is assigned by the cluster and cannot be
changed, but the Edit label action allows assigning a custom label.
Furthermore, a small text note can be attached to the application with the
Edit note action. When an application has an attached note, a small
circled i with a tooltip appears next to the application name.
Clone and move#
The Clone and Move actions create a destination application
that is a copy of the source one.
The cluster node where the destination runs can be the same as the source. Instead, when moving an application, you must select a target node different from the one where the source is currently running.
Generally, there are no limitations on running multiple applications of the same type on the same node. However, in some cases, cloning or moving to certain nodes may be restricted due to application policies, node resource limits (CPU, memory), or because the application requires exclusive access to a system resource, such as binding a fixed TCP port.
Once started, Clone and Move actions run through these steps:
Create the destination application. This step may include the selection of an additional volume for the application data, as explained in Install applications.
Start the data transfer between source and destination. During this step, the source remains up and running.
Briefly stop the source application (when required by its data synchronization strategy).
Execute the final data synchronization.
The final step differs between the two actions:
For Clone, start both the source and the destination applications.
For Move, start the destination application and remove the source one.
If the moved application is referenced by a fully qualified domain name (FQDN), ensure that external DNS records are updated to point to the target node. The cluster reverse proxy is automatically reconfigured.
Restart application#
The Restart action fully stops the application and starts its services
again, performing the same operations normally executed at node boot time.
This action should be used sparingly and preferably during non-working hours, as it interrupts application operation with unpredictable effects on the end-user experience.
Some unpredictable events, such as lack of disk space or memory
exhaustion, may degrade application functionality. In these situations,
Restart may resolve the issue, provided that sufficient resources are
available again.
Core apps#
From the Applications page, select the Core apps button to
see a full list of installed Core applications and their versions. Core
updates, when available, are always applied at the same time.
The module term#
The module term is often used by developers. An NS8 application is implemented by a unit called a module. It is usually composed of one or more Linux containers and a user interface for its configuration. A module is the deployable unit managed by the cluster orchestrator.
The terms application and module are almost synonyms in the context of NS8. However, some modules provide services to other modules and do not include a configuration UI. For example, Core components such as Loki and Grafana are implemented as modules running on the leader node.