The Go runtime/metrics package currently exports extremely granular
histograms. Exponentially bucket any histogram with unit "seconds"
or "bytes" instead to dramatically reduce the number of buckets, and
thus the number of metrics.
This change also adds a test to check for expected cardinality to
prevent cardinality surprises in the future.
Signed-off-by: Michael Anthony Knyszek <mknyszek@google.com>
A previous PR made it so that the Go 1.17 collector locked only around
uses of rmSampleBuf, but really that means that Metric values may be
sent over the channel containing some values from future metrics.Read
calls. While generally-speaking this isn't a problem, we lose any
consistency guarantees provided by the runtime/metrics package.
Also, that optimization to not just lock around all of Collect was
premature. Truthfully, Collect is called relatively infrequently, and
its critical path is fairly fast (10s of µs). To prove it, this change
also adds a benchmark.
name old time/op new time/op delta
GoCollector-16 43.7µs ± 2% 43.2µs ± 2% ~ (p=0.190 n=9+9)
Note that because the benchmark is single-threaded it actually looks
like it might be getting *slightly* faster, because all those Collect
calls for the Metrics are direct calls instead of interface calls.
Signed-off-by: Michael Anthony Knyszek <mknyszek@google.com>
* Check validity of method and code label values
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Use more flexibly functional option pattern for configuration
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Update documentation
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Simplify
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
* Fix inconsistent method naming
Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>
This change introduces use of the runtime/metrics package in place of
runtime.MemStats for Go 1.17 or later. The runtime/metrics package was
introduced in Go 1.16, but not all the old metrics were accounted for
until 1.17.
The runtime/metrics package offers several advantages over using
runtime.MemStats:
* The list of metrics and their descriptions are machine-readable,
allowing new metrics to get added without any additional work.
* Detailed histogram-based metrics are now available, offering much
deeper insights into the Go runtime.
* The runtime/metrics API is significantly more efficient than
runtime.MemStats, even with the additional metrics added, because
it does not require any stop-the-world events.
That being said, integrating the package comes with some caveats, some
of which were discussed in #842. Namely:
* The old MemStats-based metrics need to continue working, so they're
exported under their old names backed by equivalent runtime/metrics
metrics.
* Earlier versions of Go need to continue working, so the old code
remains, but behind a build tag.
Finally, a few notes about the implementation:
* This change includes a whole bunch of refactoring to avoid significant
code duplication.
* This change adds a new histogram metric type specifically optimized
for runtime/metrics histograms. This type's methods also include
additional logic to deal with differences in bounds conventions.
* This change makes a whole bunch of decisions about how runtime/metrics
names are translated.
* This change adds a `go generate` script to generate a list of expected
runtime/metrics names for a given Go version for auditing. Users of
new versions of Go will transparently be allowed to use new metrics,
however.
Signed-off-by: Michael Anthony Knyszek <mknyszek@google.com>
This function calculates exponential buckets with different arguments
than the existing ExponentialBuckets function. Instead of specifying the
start and factor, the user can specify the min and max bucket value. We
have been doing it this way internally at my company for some time.
Signed-off-by: Seth Bunce <seth.bunce@getcruise.com>
Since 1.16 is out, we still support the last four minor releases.
The bump was required by the prometheus/procfs package using the new
`%w` printf directives. However, it also allows us to remove some
special casing about build info.
Signed-off-by: beorn7 <beorn@grafana.com>
Without this fix, the `InstrumentHandler...` middlewares get locked in
an endless loop in case of an invalid Collector, eating all the memory.
Signed-off-by: beorn7 <beorn@grafana.com>
MetricVec was already exported in early versions of this library, but
nobody really used it to implement vectors of custom Metric
implementations. Now #796 has shown up with a fairly special use case
for which I'd prefer a custom implementation of a special
"auto-sampling histogram" outside of this library. Therefore, I'd like
to reinstate support for creating vectors of custom Metric
implementations.
I played around for quite some while with the option of a separate
package providing the tools one would need to create vectors of custom
Metric implementations. However, with the current structure of the
prometheus/client_golang/prometheus package, this leads to a lot of
complications with circular dependencies. (The new package would need
the primitives from the prometheus package, while the existing metric
vectors like GaugeVec need to import the new vector package to not
duplicate the implementation. Separating vector types from the main
prometheus package is out of the question at this point because that
would be a breaking change.)
Signed-off-by: beorn7 <beorn@grafana.com>
I assume older Nanoc versions rendered the anchors with commas, but
the current doesn't.
Also, this adds the same link to another doc comment where it is also
relevant.
Signed-off-by: beorn7 <beorn@grafana.com>
`github.com/golang/protobuf/proto` is deprecated in lieu of
`google.golang.org/protobuf/proto`. However, we cannot simply
migrate. Types from the proto package are exposed to users of packages
in this repo. If we migrate here, users have to migrate to. Thus, we
could only migrate with a major version bump.
In different news, with all the inline lint:ignore comments, including
the existing ones, there is no need to repeat the exception in the
Makefile.
A current version of `staticcheck` is happy with the code after this
commit. golangci-lint is broken at the moment, however, and ignores
the lint:ignore comments in the code as well as those via envvar.
Signed-off-by: beorn7 <beorn@grafana.com>
Now that we have also added CollectAndLint and GatherAndLint, I
thought we should bring CollectAndCount in line. So:
- Add GatherAndCount.
- Add filtering by metric name.
- Add tests.
Minor wart: CollectAndCount should now return `(int, error)`, but that
would be a breaking change as the current version just returns
`int`. I decided to let the new version panic when it should return an
error. An error is anyway very unlikely, so the biggest annoyance here
is really just the inconsistency.
Signed-off-by: beorn7 <beorn@grafana.com>
An empty job name was always an error, but it was previously only
detected when pushing to the PGW and receiving an error. With this
commit, the error is detected before pushing.
An empty label value should have been OK but was encoded in a way that
couldn't be pushed to the
PGW. Cf. https://github.com/prometheus/pushgateway/issues/344 . This
commit changes the creation of the path in the URL so that it works
with empty label values.
Signed-off-by: beorn7 <beorn@grafana.com>
Also, change all the `dto.MetricFamily` arguments to pointers to be
more consistent with what we do in client_golang in general.
Signed-off-by: beorn7 <beorn@grafana.com>
Document the example usage of ConstLabels to register several GaugeFuncs
on the same metric name. Also reference it from the NewCounterFunc
documentation as it's similar.
Ref: https://github.com/prometheus/client_golang/pull/736
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
Bartlomiej Plotka