Commit Graph

22 Commits

Author SHA1 Message Date
Karsten Weiss e01f7ec4fb Remove unnecessary conversion
Fixes:
go_collector.go:268:66⚠️ unnecessary conversion (unconvert)

Signed-off-by: Karsten Weiss <knweiss@gmail.com>
2018-04-13 23:18:25 +02:00
hazey.dazey f36d4a3e73 Add new default metric go_info 2017-07-23 23:36:09 +02:00
Francis Stephens 56cf0be13f Adding GCCPUFraction metric to goCollector 2017-02-22 17:26:08 +01:00
Peng Gao efb2f142f3 goCollector: change goroutines and treads type
Change gorountines and threads created Gauge to NewConstMetric.

Signed-off-by: Peng Gao <peng.gao.dut@gmail.com>
2017-02-15 13:06:22 +08:00
Peng Gao fa1cd67d1e goCollector: add thread count gauge in goCollector
Signed-off-by: Peng Gao <peng.gao.dut@gmail.com>
2017-02-13 19:39:00 +08:00
beorn7 6bff9dc5a4 Make heap_released_bytes a Gauge.
It's not a counter after all.

Also, remove a misleading part of the sys_bytes help string.
2016-11-22 18:11:47 +01:00
beorn7 cf7e1caf17 Create a public registry interface and separate out HTTP exposition
General context and approch
===========================

This is the first part of the long awaited wider refurbishment of
`client_golang/prometheus/...`. After a lot of struggling, I decided
to not go for one breaking big-bang, but cut things into smaller steps
after all, mostly to keep the changes manageable and easy to
review. I'm aiming for having the invasive breaking changes
concentrated in as few steps as possible (ideally one). Some steps
will not be breaking at all, but typically there will be breaking
changes that only affect quite special cases so that 95+% of users
will not be affected. This first step is an example for that, see
details below.

What's happening in this commit?
================================

This step is about finally creating an exported registry
interface. This could not be done by simply export the existing
internal implementation because the interface would be _way_ too
fat. This commit introduces a qutie lean `Registry` interface
(compared to the previous interval implementation). The functions that
act on the default registry are retained (with very few exceptions) so
that most use cases won't see a change. However, several of those are
deprecated now to clean up the namespace in the future.

The default registry is kept in the public variable
`DefaultRegistry`. This follows the example of the http package in the
standard library (cf. `http.DefaultServeMux`, `http.DefaultClient`)
with the same implications. (This pattern is somewhat disputed within
the Go community but I chose to go with the devil you know instead of
creating something more complex or even disallowing any changes to the
default registry. The current approach gives everybody the freedom to
not touch DefaultRegistry or to do everything with a custom registry
to play save.)

Another important part in making the registry lean is the extraction
of the HTTP exposition, which also allows for customization of the
HTTP exposition. Note that the separation of metric collection and
exposition has the side effect that managing the MetricFamily and
Metric protobuf objects in a free-list or pool isn't really feasible
anymore. By now (with better GC in more recent Go versions), the
returns were anyway dimisishing. To be effective at all, scrapes had
to happen more often than GC cycles, and even then most elements of
the protobufs (everything excetp the MetricFamily and Metric structs
themselves) would still cause allocation churn. In a future breaking
change, the signature of the Write method in the Metric interface will
be adjusted accordingly. In this commit, avoiding breakage is more
important.

The following issues are fixed by this commit (some solved "on the
fly" now that I was touching the code anyway and it would have been
stupid to port the bugs):

https://github.com/prometheus/client_golang/issues/46
https://github.com/prometheus/client_golang/issues/100
https://github.com/prometheus/client_golang/issues/170
https://github.com/prometheus/client_golang/issues/205

Documentation including examples have been amended as required.

What future changes does this commit enable?
============================================

The following items are not yet implemented, but this commit opens the
possibility of implementing these independently.

- The separation of the HTTP exposition allows the implementation of
  other exposition methods based on the Registry interface, as known
  from other Prometheus client libraries, e.g. sending the metrics to
  Graphite.
  Cf. https://github.com/prometheus/client_golang/issues/197

- The public `Registry` interface allows the implementation of
  convenience tools for testing metrics collection. Those tools can
  inspect the collected MetricFamily protobufs and compare them to
  expectation. Also, tests can use their own testing instance of a
  registry.
  Cf. https://github.com/prometheus/client_golang/issues/58

Notable non-goals of this commit
================================

Non-goals that will be tackled later
------------------------------------

The following two issues are quite closely connected to the changes in
this commit but the line has been drawn deliberately to address them
in later steps of the refurbishment:

- `InstrumentHandler` has many known problems. The plan is to create a
  saner way to conveniently intrument HTTP handlers and remove the old
  `InstrumentHandler` altogether. To keep breakage low for now, even
  the default handler to expose metrics is still using the old
  `InstrumentHandler`. This leads to weird naming inconsistencies but
  I have deemed it better to not break the world right now but do it
  in the change that provides better ways of instrumenting HTTP
  handlers.
  Cf. https://github.com/prometheus/client_golang/issues/200

- There is work underway to make the whole handling of metric
  descriptors (`Desc`) more intuitive and transparent for the user
  (including an ability for less strict checking,
  cf. https://github.com/prometheus/client_golang/issues/47). That's
  quite invasive from the perspective of the internal code, namely the
  registry. I deliberately kept those changes out of this commit.

- While this commit adds new external dependency, the effort to vendor
  anything within the library that is not visible in any exported
  types will have to be done later.

Non-goals that _might_ be tackled later
---------------------------------------

There is a strong and understandable urge to divide the `prometheus`
package into a number of sub-packages (like `registry`, `collectors`,
`http`, `metrics`, …). However, to not run into a multitude of
circular import chains, this would need to break every single existing
usage of the library. (As just one example, if the ubiquitious
`prometheus.MustRegister` (with more than 2,000 uses on GitHub alone)
is kept in the `prometheus` package, but the other registry concerns
go into a new `registry` package, then the `prometheus` package would
import the `registry` package (to call the actual register method),
while at the same time the `registry` package needs to import the
`prometheus` package to access `Collector`, `Metric`, `Desc` and
more. If we moved `MustRegister` into the `registry` package,
thousands of code lines would have to be fixed (which would be easy if
the world was a mono repo, but it is not). If we moved everything else
the proposed registry package needs into packages of their own, we
would break thousands of other code lines.)

The main problem is really the top-level functions like
`MustRegister`, `Handler`, …, which effectively pull everything into
one package. Those functions are however very convenient for the easy
and very frequent use-cases.

This problem has to be revisited later.

For now, I'm trying to keep the amount of exported names in the
package as low as possible (e.g. I unexported expvarCollector in this
commit because the NewExpvarCollector constructor is enough to export,
and it is now consistent with other collectors, like the goCollector).

Non-goals that won't be tackled anytime soon
--------------------------------------------

Something that I have played with a lot is "streaming collection",
i.e. allow an implementation of the `Registry` interface that collects
metrics incrementally and serves them while doing so. As it has turned
out, this has many many issues and makes the `Registry` interface very
clunky. Eventually, I made the call that it is unlikely we will really
implement streaming collection; and making the interface more clunky
for something that might not even happen is really a big no-no. Note
that the `Registry` interface only creates the in-memory
representation of the metric family protobufs in one go. The
serializaton onto the wire can still be handled in a streaming fashion
(which hasn't been done so far, without causing any trouble, but might
be done in the future without breaking any interfaces).

What are the breaking changes?
==============================

- Signatures of functions pushing to Pushgateway have changed to allow
  arbitrary grouping (which was planned for a long time anyway, and
  now that I had to work on the Push code anyway for the registry
  refurbishment, I finally did it,
  cf. https://github.com/prometheus/client_golang/issues/100).
  With the gained insight that pushing to the default registry is almost
  never the right thing, and now that we are breaking the Push call
  anyway, all the Push functions were moved to their own package,
  which cleans up the namespace and is more idiomatic (pushing
  Collectors is now literally done by `push.Collectors(...)`).

- The registry is doing more consistency checks by default now. Past
  creators of inconsistent metrics could have masked the problem by
  not setting `EnableCollectChecks`. Those inconsistencies will now be
  detected. (But note that a "best effort" metrics collection is now
  possible with `HandlerOpts.ErrorHandling = ContinueOnError`.)

- `EnableCollectChecks` is gone. The registry is now performing some
  of those checks anyway (see previous item), and a registry with all
  of those checks can now be created with `NewPedanticRegistry` (only
  used for testing).

- `PanicOnCollectError` is gone. This behavior can now be configured
  when creating a custom HTTP handler.
2016-08-02 18:46:22 +02:00
Harmen e48dd8ee97 fix go_memstats_last_gc_time_seconds division 2016-02-08 01:28:30 +01:00
Kevin Pike db58b27d95 heap bytes released total 2015-10-07 11:21:49 -07:00
Kevin Pike 1eb8d032a8 use counter for heap released bytes 2015-10-06 08:18:17 -07:00
Kevin Pike 9a6b9d3ddf fix descriptions 2015-10-05 09:27:28 -07:00
Kevin Pike 6c7a1db6bf don't reuse memstats 2015-10-05 07:37:59 -07:00
Kevin Pike 8a031ee219 unembed memstats collector 2015-10-02 18:10:36 -07:00
Kevin Pike c945ed62c1 use metrics struct. include more statistics 2015-07-21 20:29:02 -07:00
Kevin Pike 5e9294fbb7 continue to fix errors 2015-07-21 08:38:46 -07:00
Kevin Pike 59305998f6 remove prometheus namespace references, copy paste error 2015-07-21 08:34:50 -07:00
Kevin Pike b14b149930 use counters where applicable, improve descriptions 2015-07-21 08:24:22 -07:00
Kevin Pike 8a6e3ecf23 adds general and heap memory statistics 2015-07-20 20:55:38 -07:00
Tobias Schmidt 765c1152ca Rename process_goroutines to go_goroutines
The decision was made to use the language name for language specific
metrics, so go_goroutines is the right names similar to
go_gc_duration_seconds.
2015-05-19 15:47:08 -04:00
Oliver 21b132f5a2 record quantiles as well 2015-05-05 12:33:35 -04:00
Oliver ff586eaac1 Add garbage collection stats 2015-05-05 09:52:36 -04:00
Tobias Schmidt dbd48d666b Add ProcessCollector and GoCollector
This change adds two new collectors to the prometheus package which
export metrics about a given or the current process.

* ProcessCollector exports metrics about cpu time, vss, rss, fd usage as
  well as the start time of a given process.
* GoCollector exports currently only the number of active goroutines.
2014-12-22 13:49:45 -05:00