N-central Help

Local agent

SolarWinds N-central agents monitor the devices that they have been installed on, and report data about the device to the SolarWinds N-central server. To monitor devices where an agent cannot be installed, SolarWinds N-central relies on probes. SolarWinds N-central agents are available for devices with variants of the following OSs:

  • Windows
  • Mac OS X
  • Red Hat, CentOS and Ubuntu Linux

Local agent properties

INSTALLATION AND UPGRADE DETAILS

Install Local Agent

Select this option to install an agent on the device.

Activation Key

SolarWinds N-central generates an agent activation key when you install the agent software on the device.

Agent Installer

The file name (and a hyperlink) of the software application to install the appropriate agent type on the device.

Installed Agent version

The version of the agent currently installed on the device.

Agent Update Available

Indicates whether or not an updated version of the agent is available to be installed.

Log

The file name (and a hyperlink) of the agent's log file.

Update New Version

Select how the agent will be updated to the newest version.

Status

The current status of any Agent installation operations.

The installation status is only available for Windows Agents. SolarWinds N-central attempts to install the agent every six hours for a total of 12 times in 72 hours. After 12 attempts, the installation status is indicated as Failed and a Retry button becomes available.

CONFIGURATION DETAILS

Update Monitored Address

Select to update the network address when the device's local IP address changes based on data gathered by the agent.

For this feature to work properly, the Local IP service must first be applied to the device.

Log Level

The amount of detail that the Agent is to record in the log file as one of the following:

  • 1 - Critical Errors Only: Only critical errors are logged.
  • 2 - All Errors: All of the errors are logged.
  • 3 - Normal: Basic information on the errors and messages is logged.
  • 4 - More Detail: Detailed information on the errors and messages is logged.
  • 5 - Most Detail: A full account of the errors and messages is logged. This level should only be used when debugging or troubleshooting.

Appliance ID

A read-only value that displays the appliance ID generated by SolarWinds N-central for the agent. This is used for troubleshooting purposes.

COMMUNICATION SETTINGS

Protocol

The protocol (either HTTP or HTTPS) that the agent must use to communicate with the SolarWinds N-central server.

Server Address

The IP address or FQDN to be used to establish a connection to the SolarWinds N-central server. If a connection cannot be established with the first address provided, additional addresses can be configured to provide fail-over functionality.

  1. Click Add.
  2. Click the pencil icon () beside the new address to edit it.
  3. Type the new IP address or FQDN.
  4. Press Enter.

To remove an IP address or FQDN:

  1. Select the check box next to the address.
  2. You can select the check box next to the Server Address column heading to select all of the addresses.

  3. Click Delete.

Notes:

  • Addresses will be attempted in the order in which they are configured.
  • If agents are using a failover address, they will continue to communicate with the SolarWinds N-central server through the address they are currently using until they are re-started at which time they will attempt to communicate using the first address configured in the list.
  • If the agent communicates with the SolarWinds N-central server through a port-forwarder, type the port-forwarder address.
  • If the agent communicates with the SolarWinds N-central server through a NAT firewall, type the IP address of the firewall.
  • If you type an FQDN, you must verify that the agent is configured to use a DNS server that can resolve the FQDN.

Port Number

The port that the agent uses to establish a connection to the SolarWinds N-central server. In typical configurations, the port value is 80 for an HTTP protocol and 443 for an HTTPS protocol except when the SolarWinds N-central server is behind a port-forwarder.

Proxy String

Type a valid network address. Both authenticating and non-authenticating proxies are supported.

For authenticating proxies, the following are examples of proxy strings:

  • username@hostname:port
  • username:password@hostname:port
  • domain_name\\username@hostname:port

For not-authenticating proxies, the following are examples of proxy strings:

  • hostname:port
  • domain_name\\hostname:port

Capture Agent Logs

Click Capture Logs to retrieve agent logs. The logs are compressed into a .ZIP file to be downloaded.

Depending on their size and number, retrieval of Agent logs may take up to five minutes.

ASSET SCAN

Perform Asset Scan

Select this option to configure the settings for an asset discovery scan, if required

Asset Scan Schedule

Select the Start Time, Days of the Week, and, Days of the Month when you would like the asset discovery scan to be performed.

MONITORING DATA PERSISTENCE (see Data Persistence below for additional details)

Drop Policy

Select the criteria to indicate when the data window has been exceeded from one of the following:

  • Oldest - discards the oldest cached data first, or.
  • Newest - discards the newest cached data first.

Data Window

Select the maximum span (in hours and minutes) of data to be cached on the agent.

If the span is exceeded, the data that is discarded depends on the drop policy. For example, if you specify two hours and the drop policy is configured as Newest, any new data will be discarded after more than two hours of data has been cached.

The local time is used to cache data and determine the expired data span.

Minimum Free Disk Space

Select the minimum amount of disk space (in MBs, GBs, TBs, or %) required to be available on the Agent before data can be cached.

Maximum Disk Space

Select the maximum amount of disk space (in MBs, GBs, TBs, or %) on the Agent that can be used for caching data.

Data Persistence

When setting up a Windows, Linux, or Mac OS X agent, you can also set the agent's data persistence settings. This allows the agent to cache data for a specified length of time if the connection to the central server is down. However, data will not be cached if the available disk space on the agent is less than the specified minimum.

If the data being cached begins to exceed the specified length of time or the available disk space, the data is discarded based on the drop policy. The drop policy determines whether the oldest or newest data is discarded. If the drop policy is the oldest, then the oldest record is discarded as each new record is cached. If the drop policy is the newest, then any new data is immediately discarded.

During the time that the connection between the agent and central server is down, the statuses for the services being monitored by the agent are displayed as stale. After the connection to the central server is restored, the agent transfers all of the cached data to the central server. The central server compares the most recent information in the cached data to the original data before the connection went down to determine whether the service status has changed. If there is a change, the new service statuses are displayed on the dashboards and the appropriate notifications are triggered.

For example, if the status was green before the connection went down, but red in the last record of the cached data sent to the central server, then in comparing the two, the central server will trigger a notification. Refer to the image below.

Cached Data using Newest Drop Policy

However, if the last record of the cached data sent to the central server is green, then a notification is not triggered. Refer to the image below. The data, however, can still be retrieved through historical reports.

Cached Data using Oldest Drop Policy