Span API

A span measures the duration of a single event. When a span is created it will measure the time until span.end() is called.

To get a Span object, you need to call apm.startSpan().

`span.name`

Type: String
Default: Unknown

The name of the span. This can also be set via apm.startSpan().

`span.type`

Type: String
Default: custom

The type of span. This can also be set via apm.startSpan().

The type is a hierarchical string used to group similar spans together. For instance, all outgoing AJAX requests are given the type external.http.

In the above example, external is considered the type prefix. Though there are no naming restrictions for this prefix, the following are standardized across all Elastic APM agents: app, db, cache, template, and external.

`span.addLabels()`

span.addLabels({ [name]: value })

Add several labels on the span. If an error happens during the span, it will also get tagged with the same labels.

Arguments:

name - Any string. All periods (.), asterisks (*), and double quotation marks (") will be replaced by underscores (_), as those characters have special meaning in Elasticsearch
value - Any string, boolean, or number. All other data types will be converted to a string before being sent to the APM Server.

`span.end()`

span.end()

Ends the span. If the span has already ended, nothing happens.