Set up a load balancing behavior

When multiple MID Servers are configured to scan the same protocol, users can set up a load balancing behavior to automatically balance the work between the MID Servers.

About this task

Behaviors enable load balancing when multiple MID Servers are configured to scan the same protocol. For example, an organization has fifty remote locations, varying in size from 10 devices to several hundred devices. All the satellite offices are part of the same Windows domain, which is administered from a central location. There are three MID Servers installed at this central location: two to scan all the Windows devices and one to scan the remaining devices. Because some of the remote offices are in different time zones, different schedules must be created to run Discovery at off-peak hours in each time zone. The same behavior can be used for each schedule, and the behavior will load-balance the two Windows MID Servers automatically.

Procedure

  1. Create the behavior record.
    1. Create a new Discovery behavior record, and name it something descriptive, such as LoadBalanced.
    2. Right-click in the header bar and select Save from the pop-up menu.

      This action saves the record and creates the Discovery Functionality related list in the form.

  2. Define the Windows functionality.
    1. Click New in the Discovery Functionality related list.
    2. Create a new record using the fields described here.
    3. Right-click in the header bar and select Save from the pop-up menu.
    Field Input Value
    Phase Type a phase number of 1 in this field.
    Functionality Select Windows only (WMI) from the list. This functionality defines the protocol that will be scanned. Because we selected to scan WMI, we must select Windows MID Servers for this functionality.
    MID Servers We select the two MID Servers that we want to share the load for the WMI probes. By entering multiple MID Servers in this field, we tell Discovery to balance the load between these servers automatically. If we were to create separate functionality for each server, load balancing would not occur.
    Active Make sure this check box is selected to enable this behavior.
    Match criteria Leave the default criteria of Any.
    Figure 1. Discovery Functionality Form
  3. Create Functionality Criteria.
    Note: All Windows functionality requires criteria to identify the Windows domain and define any special behavior for the MID Servers named.
    1. Click New in the related list.
    2. Enter the following values:
      Field Input Value
      Name We enter win_domain to name the Windows domain that Discovery will scan with the MID Servers we have defined.
      Operator Select equals as the operator in this criteria.
      Value This is the name of the Windows domain that these MID Servers will scan for devices.
      Active Be sure to enable the criteria by selecting this check box (true).

      The completed criteria appear in the Discovery Functionality form for the Windows MID Servers.

      Figure 2. Completed Discovery Functionality Form
  4. Define the functionality for the remaining scans.

    Create a second record to scan for all the remaining protocols (SSH, SNMP, etc), using the following settings:

    Field Input Value
    Phase Type a phase number of 1 in this field. This phase will be executed at the same time as the WMI scans and with the same Shazzam probe. We use the same phase number for efficiency and because we know that none of the devices in the target IP ranges are running multiple protocols (e.g. SSH and SNMP). If any devices were running multiple protocols, we would want to specify a second or even a third phase to discover the correct protocol first for each device.
    Functionality Select All except Windows (no WMI) from the list. This functionality causes the MID Server to scan all remaining protocols after Discovery has run the WMI scans.
    MID Servers Name the MID Server that will scan for all other devices. If we want to use automatic load balancing, we can add an additional MID Server to this field.

    The completed Discovery Behavior form looks like this. It is not necessary to create Functionality Criteria for this MID Server.

    Figure 3. Completed Discovery Behavior Form
  5. Define the functionality for the remaining scans.

    Create a second record to scan for all the remaining protocols (SSH, SNMP, etc), using the following settings:

    Field Input Value
    Phase Type a phase number of 1 in this field. This phase will be executed at the same time as the WMI scans and with the same Shazzam probe. We use the same phase number for efficiency and because we know that none of the devices in the target IP ranges are running multiple protocols (e.g. SSH and SNMP). If any devices were running multiple protocols, we would want to specify a second or even a third phase to discover the correct protocol first for each device.
    Functionality Select All except Windows (no WMI) from the list. This functionality causes the MID Server to scan all remaining protocols after Discovery has run the WMI scans.
    MID Servers Name the MID Server that will scan for all other devices. If we want to use automatic load balancing, we can add an additional MID Server to this field.

    The completed Discovery Behavior form looks like this. It is not necessary to create Functionality Criteria for this MID Server.

    Figure 4. Completed Discovery Behavior Form
  6. Create a schedule recordfor each time zone and name the behavior we just created..
    1. Navigate to Discovery > Discovery Schedules and click New in the record list.
    2. Select a Discover type of Configuration items.
      This action displays the Behavior field.
    3. Click the magnifier icon and select the behavior to use. In our example, we select LoadBalanced.
    4. Select the appropriate time to run Discovery for this location.
    5. Click Quick Ranges and define the IP address ranges, networks, or lists to scan for this location.
    6. Save the record.
    7. Create additional schedules for each time zone or region in the network and select the same behavior.
    Figure 5. Discovery Schedule