5.2. Discovering Resources

When an agent is installed and every time it starts up, it scans the platform, and all applications on it, for any servers, services, or other items which can be included into the inventory. The process of finding potential resources is called discovery.

There are different scans for each type of resource: platform, server, and service. High level scans for servers and platforms are initiated by the agent every 15 minutes. A service scan detects lower-level services that are running in servers that have already been imported into the inventory. These scans run by default every 24 hours. Both of these intervals are configurable in the JBoss ON agent configuration.

The agent always runs a scan for new resources when it starts up, and then periodically at its configured intervals. There is a delay between when the parent and immediate resources are imported and when another discovery scan is initiated to discover lower-level children; this prevents possibly long-running recursive discovery scans for resources which may potentially be ignored.

JBoss ON agents send information about the platform and servers it discovers back to the JBoss ON server.

A server must be imported into the inventory before any of its child processes, servers, or services can be detected by the discovery scan.

When a platform is imported into the inventory, several of its child servers and services are imported automatically as well. This includes resources that are vital to the platform (like CPU, network adapters, and filesystems) as well as resources that are used by the JBoss ON server itself (such as the Ant bundle handler resource, which is used by the provisioning subsystem).

Although discovery is run automatically by the agent, discovery can also be initiated manually to capture infrastructure changes immediately.

Discovery scans are run automatically by the agent to identify new resources as they are added to a platform. Server scans are run every 15 minutes and service scans every 24 hours. (Additionally, the agent runs a full discovery scan when it starts up.) New resources can be added between the discovery scans, so administrators can initiate a manual discovery scan apart from the scheduled discovery scan.

The simplest way to initiate a discovery scan is to run the agent's discovery command at the agent command prompt:

When the JBoss ON agent discovers an application or service which is to be ignored from the inventory, the server can be instructed to ignore those resources in the discovery queue. If the resource has already been imported to the inventory, see Section 5.2.5, “Ignoring Imported Resources”.

Once a resource has been imported into the JBoss ON inventory, the server and the managing agent can be set to ignore those resources. There are three locations within the JBoss ON User Interface where you set a resource to ignore;

The procedure in Section 5.2.4, “Ignoring Discovered Resources” is for ignoring a single, specific resource after it has been discovered on the system. Other resources of the same type on that platform or other platforms will still be discovered and included in the inventory. Ignoring that one resource has no impact on the discovery process.

However, there may be certain types of resources which will never be imported into the inventory. For example, filesystem resources may always be ignored on platforms, or a low-level EJB service may always be ignored on an EAP 6 server. In those instances, there is a maintenance overhead to discovering resources on the agent, having an administrator manually ignore them, and then maintaining them in inventory as an ignored resource.

If a certain type of resource will never be monitored or managed by JBoss ON, then that entire resource type can be ignored. This essentially disables discovery for that resource type.

Ignoring a resource type is a global, JBoss ON-wide setting and is configured in the JBoss ON server configuration.