Vespa provides metrics integration with CloudWatch, Datadog and Prometheus / Grafana, as well as a JSON HTTP API. See monitoring with Grafana quick start if you just want to get started monitoring your system.
There are two main approaches to transfer metrics to an external system:
Have the external system pull metrics from Vespa
Make Vespa push metrics to the external system
Types: All rank feature values are floats. Ints are converted to exact whole value floats. String values are converted to exact whole value floats using a hash function. String literals in rank expressions are converted using the same hash function, to enable equality tests on string values.
Features which are normalized are between 0 and 1, where 0 is always the minimum and 1 the maximum. Normalized features should normally be preferred because they are more easily combined by ranking expressions into a complete normalized score.
A query may override any rank feature value by submitting that value as a feature with the query.
Some features have parameters. It is always allowed to quote parameters with “. Nested quotes are not allowed and must be escaped using \. Parameters that can be parsed as feature names may be left unquoted. Examples: foo(bar(baz(5.5))), foo(“bar(\”baz(\\\”5.5\\\”)\”)”), foo(“need quote”)