Figuring out what's going on with the new service discovery
and labels is difficult. Add a popover with the labels
to the target table to make things simpler, and help
discovery of potentially useful labels.
Previously we redirected any non-existent path to the root (or path
prefix).
The new behavior:
With no path prefix:
- "" -> "/"
- "/biz" -> 404
With path prefix of "/foo/bar":
- "" -> "/foo/bar/"
- "/" -> "/foo/bar/"
- "/foo/bar" -> "/foo/bar/"
- "/biz" -> /foo/bar/biz"
(anything not starting with the path prefix gets the prefix prepended)
- "/foo/bar/biz" -> 404
This change is conceptually very simple, although the diff is large. It
switches logging from "github.com/golang/glog" to
"github.com/prometheus/log", while not actually changing any log
messages. V(1)-style logging has been changed to be log.Debug*().
Appending to the storage can block for a long time. Timing out
scrapes can also cause longer blocks. This commit avoids that those
blocks affect other compnents than the target itself.
Also the Target interface was removed.
The target implementation and interface contain methods only serving a
specific purpose of the templates. They were moved to the template
as they operate on more fundamental target data.
With this commit, sending SIGHUP to the Prometheus process will reload
and apply the configuration file. The different components attempt
to handle failing changes gracefully.
This commits renames the RuleManager to Manager as the package
name is 'rules' now. The unused layer of abstraction of the
RuleManager interface is removed.
This commit shifts responsibility for maintaining targets from providers and
pools to the target manager. Target groups have a source name that identifies
them for updates.
This adds the population standard deviation and
variance as aggregation functions, useful for
spotting how many standard deviations some samples
are from the mean.
Don't handle `0` as a special timestamp value for "now" anymore, except
in the `QueryRange()` case, where existing API consumers still expect
`0` to mean "now".
Also, properly return errors now for malformed timestamp/duration
float values.
