* Add /api/v1/format_query API endpoint for formatting queries
This uses the formatting functionality introduced in
https://github.com/prometheus/prometheus/pull/10544.
I've chosen "query" instead of "expr" in both the endpoint and parameter
names to stay consistent with the existing API endpoints. Otherwise, I
would have preferred to use the term "expr".
Signed-off-by: Julius Volz <julius.volz@gmail.com>
* Add docs for /api/v1/format_query endpoint
Signed-off-by: Julius Volz <julius.volz@gmail.com>
* Add note that formatting expressions removes comments
Signed-off-by: Julius Volz <julius.volz@gmail.com>
- For now this is relatively simplistic, but at least acknowledges some
of the basics, and points out some parts that might not be obvious at first.
Relates to #7192
Signed-off-by: Harold Dost <h.dost@criteo.com>
This follow a simple function-based approach to access the count and
sum fields of a native Histogram. It might be more elegant to
implement “accessors” via the dot operator, as considered in the
brainstorming doc [1]. However, that would require the introduction of
a whole new concept in PromQL. For the PoC, we should be fine with the
function-based approch. Even the obvious inefficiencies (rate'ing a
whole histogram twice when we only want to rate each the count and the
sum once) could be optimized behind the scenes.
Note that the function-based approach elegantly solves the problem of
detecting counter resets in the sum of observations in the case of
negative observations. (Since the whole native Histogram is rate'd,
the counter reset is detected for the Histogram as a whole.)
We will decide later if an “accessor” approach is really needed. It
would change the example expression for average duration in
functions.md from
histogram_sum(rate(http_request_duration_seconds[10m]))
/
histogram_count(rate(http_request_duration_seconds[10m]))
to
rate(http_request_duration_seconds.sum[10m])
/
rate(http_request_duration_seconds.count[10m])
[1]: https://docs.google.com/document/d/1ch6ru8GKg03N02jRjYriurt-CZqUVY09evPg6yKTA1s/edit
Signed-off-by: beorn7 <beorn@grafana.com>
Since Prometheus documentation is versioned, do not write down that a
specific function was added in Prom 2.0, for consistency.
Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
* Provide a callout about the vector matching keywords and the group
modifiers.
Relates prometheus/docs#2106
Signed-off-by: Harold Dost <h.dost@criteo.com>
Split out the note about regex-matching into a separate paragraph to
make it more obvious. Move it up, closer to the definition.
Signed-off-by: SuperQ <superq@gmail.com>
This follows the line of argument that the invariant of not looking
ahead of the query time was merely emerging behavior and not a
documented stable feature. Any query that looks ahead of the query
time was simply invalid before the introduction of the negative offset
and the @ modifier.
Signed-off-by: beorn7 <beorn@grafana.com>
Since `/api/v1/write` is a mutating endpoint, we should still activate
the remote-write-receiver explicitly. But we should do it in the same
way as the other mutating endpoints, i.e. via a flag
`--web.enable-remote-write-receiver`.
This commit marks the feature flag as deprecated, i.e. it still works
but logs a warning on startup. This enables users to seamlessly
migrate. With the next minor release, we can start ignoring the
feature flag (but still warn a user that is trying to use it).
Signed-off-by: beorn7 <beorn@grafana.com>
