Smarts NCM: Can the API be queried for chassis serial numbers of devices in a stack

Products

• VMware Smart Assurance

Environment

VMware Smart Assurance - NCM

Resolution

The NCM API gives remote access to a broad subset of functions and data that is ordinarily available to end users of the NCM Client UI. However, formatting and display based views of that data as presented in the Client UI are not always available. Serial numbers of device chassis for devices that participate in a stack under the same management IP address are an example of one instance where the data is not readily available through the API in the same, simple, list format that you can see in the Client UI. Stack sub component device chassis are currently only visible through the API as content encapsulated in configuration files pulled form the stack. Since stack component devices can change, it is considered subject to revision and those changes may be possible to track through the revision history for that device. If API access to that information is desired, it is currently necessary to parse the output of device configuration files to extract the data.

To obtain a list of stack sub component device chassis serial numbers for the latest revision of a given device from the NCM PostgreSQL Control Database for use in comparing to the Client UI data or data produced by external code that parses configuration file content for that data, you can do as follows:

1. Log into a command line shell on the NCM PostgreSQL Control Database (controldb) host as 'root' (Linux) or as a user with full local administrator privileges (Windows).
2. Run the following command to log into the controldb:

            Linux:

      su - pgdba -c 'psql voyencedb voyence'

 
          Windows:

     %VOYENCE_HOME%\db\controldb\bin\psql -p 5435 -h 127.0.0.1 --username=voyence -d voyencedb

3. Run the following commands to pepare a query that can be run against any device based on the Client UI visibile Device ID value for the device that outputs the list of known component device chassis serial numbers:

      PREPARE current_stack_chassis_sn_list(int) AS
      SELECT
        h.element_name,
        h.description,
        h.serialnumber AS serial_number
      FROM cm_device d
      JOIN (
        SELECT 
          device_id,
          revision_id,
          max(revision_number)
        FROM cm_config_unit_revision
        GROUP BY 
          device_id,
          revision_id
      ) AS r
        ON d.device_id = r.device_id
      JOIN dm_hw_element_view h
        ON r.revision_id = h.revision_id
      WHERE 
        d.device_status = 'enum.deviceStatus.operational' AND
        d.is_operational_device IS TRUE AND
        element_name = 'Chassis' AND
        device_idx = $1;

To execute the query, simply use the PostgreSQL EXECUTE command with the name of the query followed by the Device ID for the device as shown in the NCM Client UI for the device. This query will remain accessible to the Execute function until the end of your current database shell session, so you can run it repeatedly using different Device ID values as needed. For example: 
 

      voyencedb=# EXECUTE current_stack_chassis_sn_list(1003);
      element_name |         description                               | serial_number
     --------------+---------------------------------------------------+---------------
      Chassis      | Cisco Catalyst 3750 (1 Slot) Chassis              | CYS14190265
      Chassis      | Cisco EtherSwitch Service Module (2 Slot) Chassis | ESM00190266
      Chassis      | Cisco EtherSwitch Service Module (3 Slot) Chassis | ESM00190267
     (3 rows)
     voyencedb=#