File-based discovery process

After the discovery, the discovered devices and their resources are stored in Cassandra database in the Inventory Service.

Discovery formulas

Discovery rules are available in the as predefined discovery formulas for specific vendors and technologies. These discovery formulas are used by Telco Network Cloud Manager - Performance to discover the vendor-specific devices and their resources.

An example of Avro record from Apache NiFi from where basic inventory and metric information can be obtained:

{
  "resource" : "deviceIP=10.71.214.65, deviceID=7340054, deviceName=FTTO_Test1, resourceID=NE:7340054;FR:0;S:5;CP:-1;PP:--0-;ONU:0, id=FTTO_Test1/Frame:0/Slot:5/Port:0/ONU ID:0, type=huaweiGponOnt, granularityPeriod=15, indicatorGroupID=IG80112",
  "time" : 1526372100000,
  "tpe" : "NUMBER",
  "kpi" : "upAverageThroughput",
  "value" : "110.00"
}

After the Technology Pack is installed, you can see the discovery formulas in the following location:
/opt/basecamp/file-collector/content/discoveries/<tech_pack>. The discovery formulas have .discovery as the file extension. These formulas contain additional discovery rules to obtain more information about the resources, properties, and their relationships.

Typically, every Technology Pack has three types of discovery formulas.

Device discovery rule
These rules are used in discovery formulas in built-in Technology Packs for resource discovery to create or enrich in-band discovered resources and the relation discovery (stitch) to create relations among the resources.
For example,
```
engine file
when resource.type like 'cabinet'
select * from local.cabinet
set vendor = 'cabinet'
set prop2 = resource.prop2
unset prop1
```

Resource and properties discovery rules that are specific to a resource type.

Optionally, formulas can contain discovery rules to obtain additional properties. For example,

engine file
when resource.type like 'cabinet'
select * from local.<reousrce_type>
set prop1 = <reousrce_type>.prop1
set prop2 = <reousrce_type>.prop2
set prop2 = <reousrce_type>.prop3

Resource relationship rules

For example,

engine file
relate device to cabinet as contain when target.name == source.prop2

nokiaDevice.discovery file contents.


engine file
when resource.vendor like 'Nokia'
select deviceName from local.gponIgmpCard UNION ALL select deviceName from local.gponMulticastSystem UNION ALL select deviceName from local.gponInterface UNION ALL select deviceName from local.gponEthernetLag UNION ALL select deviceName from local.gponCard UNION ALL select deviceName from local.gponOnt UNION ALL select deviceName from local.gponUniPort UNION ALL select deviceName from local.gponVoice UNION ALL select deviceName from local.gponOntEthernetPort UNION ALL select deviceName from local.gponVlan UNION ALL select deviceName from local.gponBridgePortVlan UNION ALL select deviceName from local.gponXdsl
set id = resource.deviceName
set name = resource.deviceName
set type = 'device'
set vendor = 'Nokia'

Discovery model files

Discovery model files are applicable for both SNMP and File-based discovery. Two types of model files are available in the Inventory Service:

/opt/itoa/services/inventory/content/model/Property

The model files have .model as the file extension. Every resource type has its own property model file that describes all the properties that are available in that resource type. For example, the contents of gponCard.model file is as follows:

type gponCard extends snmpPollable{
        property index String{
                required = true
        }
        property vendor String
        property id String
        property hwFrameType String
        property tpFrameId String
        property tpSlotId String
        property hwSerialNumber String
        property cardType String
        property sysName String
        property deviceType String
        property portType String
        property displayName String
        property deviceName String
        property deviceIP String
        property objectID String
        property cardID String
        property portSlot String
        property portShelf String
        property portRack String
        property portPort String
        property card String
        property portCard String
        property deviceID String
        property resourceID String
        property granularityPeriod String
        property waitPeriod String
        property interval String
}
}

/opt/itoa/services/inventory/content/model/Relationship
The model files have .model as the file extension. Every resource type has its own relationship model file that describes the resource grouping based on the resource type and the device. For example, the contents of device-card.model file is as follows:
```
relationship contain device ->> card
```

Stages in discovery

Apache NiFi and File Collector Service parse and extract the information from the input files from EMS.