Cisco Observability Platform Query Service API

MELT Type - NAMESPACE

MELT types (entities, associations, metrics, and events) are organized as AppD Types in the schema. AppD Types consist of two parts, namespace and type name.

AppD Types are often used in UQL queries. The syntax to use a AppD Type is <namespace>:<type name>. For example apm:service, apm is the namespace and service is the type name.

Code Snippet
CopyExample

FETCH 
  metrics(apm:calls_per_minute),
  events(common:logs)
FROM entities(apm:service)

NAMESPACES clause

You can use the NAMESPACES clause to define a comma-separated list of namespaces. Use it for the following usecases:

  • default namespaces
  • namespace aliases

Note All the clause keywords are valid in upper or lower case but not in mixed-case. Valid variants are 'namespaces' and 'NAMESPACES'.

Default NAMESPACES

With default namespace, you can specify types only as type names without namespaces and colon. The system evaluates it against a defined list of used namespaces.

Code Snippet
CopyDefault Namespaces Example

NAMESPACES apm, common
FETCH 
  metrics(calls_per_minute),
  events(logs)
FROM entities(service)

If you define type names in multiple namespaces, the query fails.

NAMESPACES aliases

NAMESPACES clause can be used for a namespaces aliasing.

Code Snippet
CopyNamespace Alias Example

NAMESPACES cloud:k8s
FETCH id
FROM entities(cloud:pod)

In this example, the entity type is resolved as k8s:pod.

Note If you do not specify a namespace alias in the NAMESPACES clause then its name is used as the alias. For example these two clauses are the same:

  • NAMESPACES apm
  • NAMESPACES apm:apm

Warning You cannot define more than one item with the same alias in the NAMESPACES.

NAMESPACES resolution

Namespaces defined within namespaces clause are applied only to object types in the query, not to object IDs.

  • Object type = a pair <namespace>:<type>, for example k8s:pod
  • Object ID = a triplet <namespace>:<type>:<ID>, for example k8s:pod:DLT6XSeFMpqQxZIZ18mYkw

Warning Object ID represents one concrete object; use the object ID as-is.

Code Snippet
Code Snippet - 1
CopyNamespace k8s will be applied to type name pod

NAMESPACES k8s
FETCH id
FROM entities(pod)

CopyNamespace k8s won’t be applied to incomplete object ID pod:DLT6XSeFMpqQxZIZ18mYkw

NAMESPACES k8s
FETCH attributes
FROM entities(pod:DLT6XSeFMpqQxZIZ18mYkw)

Default Values

Default values for the NAMESPACES clause is

Code Snippet
CopyNAMESPACES common
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