May 2023: Feature releases & highlights

• Visibility of the host call home status and progress: you can now inspect hosts calling home not yet assigned to a site and any duplicate hosts.
  
• Working with offline sites: we have documented how you can work with the Avassa command line towards a site that lost connection to the Control Tower. This assumes you are connected to the site-local network
• Documentation on resource profiles: Resource profiles are a powerful way to limit the number of resources accessible to a tenant. We have added a tutorial on how to define this using resource profiles.

Host call home status and progress

The modus operandi for adding hosts to your sites are the following:

1. Install Edge Enforcer on your host, the install command is available under your user menu:

This will display the serial number of the motherboard. When Edge Enforcer starts, it will call home to the Control Tower with this serial number to identify itself.

Add this serial number on a new host on the appropriate site:

The host will be added to the site cluster when there is a match for host id.

ℹ️ You can operate in reverse order if you know the serial ID. You can also pass an ID as a parameter to the install script if you do not want to use the default serial number mechanism.

We have now added functionality so that this process is more visible for you as a site provider:

• It is now possible to enable the Avassa System to keep a list of the last 20 hosts calling home that do not match a host id in a site. By default, these are silently dropped.
• There is a new status summary of the call home server.
• You can get a list of duplicate IDs calling home. This can be an error in your installation process or a security threat.

We will illustrate the above features below.

To the top left, you see a new section in the UI that shows the status of the call home process. We see one host calling home without a matching host id in a site, “unclaimed hosts.” In the list of sites, a new circle indicates the number of hosts that have not called home to the respective sites. In this way, you can easily follow the site rollout process.

When you select the site, you will also see configured hosts that have not yet called home.

You can also inspect the overall call home state as shown below:

If you want to inspect the unclaimed hosts, you can click the “View” link to the right of “unclaimed hosts”:

This will give you a view shown below. One frame shows unclaimed hosts, and you can open a site frame simultaneously. This will make it convenient to add unclaimed hosts to a specific site. You can also get details on each unclaimed host by selecting it.

Wrapping up this section by showing the list of duplicate hosts. In theory, you should never have different hosts calling home with the same host id. So this list should be inspected.

The relevant supctl commands are shown below:

$ supctl show system call-home unclaimed-hosts

$ supctl show system call-home duplicate-hosts

$ supctl show system call-home summary

$ supctl show system call-home settings

To enable the feature using supctl:

$ supctl create system call-home settings <<EOF
enable-unclaimed: true
EOF

Offline sites

A core feature of Avassa is that the sites form an autonomous cluster. There is no dependency on the Control Tower for the scheduler to perform healing actions on the site. A site might be disconnected from the Control Tower for long periods of time.

As a site provider or application owner, you still want to perform actions towards the sites of you have local access. For example, the internet connection might be down but not the local area network. We have written instructions on connecting supctl locally to your site.

In order not to create split-brain scenarios, there are certain things you are not allowed to perform when talking directly to the site, for example, changing application configuration.

Typical things you will do locally:

• Check cluster status
• Check application status
• Restart application services
• Consume data from the local pub/sub bus, for example, view container logs or host metrics.

Documentation on resource profiles

Avassa gives you the possibility to control which resources are available to subtenants, applications, or service instances. The following resources can be controlled:

The following types of resources are considered by the Avassa platform:

• CPU
• memory
• disk space for container storage layer
• network bandwidth
• container volumes
• hardware devices (e.g. cameras, sensors etc.)
• GPU
• ingress IP address availability

A site provider can limit the amount or set of resources available to each of its subtenants or limit the resources available on certain sites/hosts in the system by defining resource profiles.

Resource profiles can be divided into:

• Hardware resource profiles: these are defined at the system level and then associated per site, host, or system-wide.
• Tenant resource profiles: allows for restricting resources based on the tenant that deploys the application. These are defined per tenant or tenant per site.

As a site provider, you can have fine-grained control over resource usage in your edge infrastructure.

We have added a tutorial on resource profiles that elaborates on how to do this.