Timestamps

Both vertex and edge graph elements can have multiple timestamps, documented here.

Timestamp formats

The following formats apply across all Agile Service Manager APIs when specifying timestamps:
Millisecond Epoch
Example:
$ date "+%s%3N"
1595261016885
RFC-3339 / ISO-8601
Format: 
YYYY-MM-DDThh:mm:ss.sssZ
Example:
$ date --universal "+%FT%T.%3NZ"
2020-07-20T16:03:00.382Z

beginTime

The beginTime timestamp records the beginning of a period of time for which the resource was valid, with endTime marking the end of that period.
Tip: A given resource may have multiple begin times in its historic record, and there may be gaps in that record if the resource was offline for periods.
  • All resources and historic resources that are representations of the same thing have a distinct beginTime
  • Resource beginTime together with endTime is used in historic graph traversals, that is, when the _at parameter is supplied. The period during which a resource is valid is defined as: 
    atTime >= beginTime && atTime < endTime
  • A vertex or edge which has the beginTime equal to the endTime can be used to store audit information, such as the provider which deleted a given resource. However, because it takes up zero time it does not form part of the history and is ignored by the above equation.

prevBeginTime

If history exists for a given resource then this property will be set to the beginTime of the most recent historical resource.

changeTime

The changeTime timestamp records when the properties of the element last changed.

Its value may be less than the observedTime, which is updated on a POST or PUT even if no property values have changed.

createTime

The createTime timestamp records when the element was first created in the topology service.
  • Historical resources do not store createTime, as it is shared with the anchor.
  • This is needed when looking for something older than 30 days, that is, when there is no beginTime this old because the historical resources have timed out.

endTime

The endTime timestamp records when the element was deleted.
  • All resources and historic resources that are representations of the same thing have a distinct endTime.
  • Resource endTime is used in historic graph traversals, that is, when the _at parameter is supplied.
  • For current resources, endTime is LONG_MAX. This is sometimes hidden via the REST API.

observedTime

The observedTime timestamp records when the element was last observed, that is, when data was last input to the topology service for the element.