e3c37a46e2
at the first iteration, only the following metrics are collected:
- HTTP metrics of each API endpoint
- cache counter for request/hit/miss
- histogram of storage actions, including:
GetContent, PutContent, Stat, List, Move, and Delete
Signed-off-by: tifayuki <tifayuki@gmail.com>
75 lines
3.5 KiB
Go
75 lines
3.5 KiB
Go
// Copyright 2014 The Prometheus Authors
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package prometheus
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// Collector is the interface implemented by anything that can be used by
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// Prometheus to collect metrics. A Collector has to be registered for
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// collection. See Registerer.Register.
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//
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// The stock metrics provided by this package (Gauge, Counter, Summary,
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// Histogram, Untyped) are also Collectors (which only ever collect one metric,
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// namely itself). An implementer of Collector may, however, collect multiple
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// metrics in a coordinated fashion and/or create metrics on the fly. Examples
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// for collectors already implemented in this library are the metric vectors
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// (i.e. collection of multiple instances of the same Metric but with different
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// label values) like GaugeVec or SummaryVec, and the ExpvarCollector.
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type Collector interface {
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// Describe sends the super-set of all possible descriptors of metrics
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// collected by this Collector to the provided channel and returns once
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// the last descriptor has been sent. The sent descriptors fulfill the
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// consistency and uniqueness requirements described in the Desc
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// documentation. (It is valid if one and the same Collector sends
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// duplicate descriptors. Those duplicates are simply ignored. However,
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// two different Collectors must not send duplicate descriptors.) This
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// method idempotently sends the same descriptors throughout the
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// lifetime of the Collector. If a Collector encounters an error while
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// executing this method, it must send an invalid descriptor (created
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// with NewInvalidDesc) to signal the error to the registry.
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Describe(chan<- *Desc)
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// Collect is called by the Prometheus registry when collecting
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// metrics. The implementation sends each collected metric via the
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// provided channel and returns once the last metric has been sent. The
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// descriptor of each sent metric is one of those returned by
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// Describe. Returned metrics that share the same descriptor must differ
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// in their variable label values. This method may be called
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// concurrently and must therefore be implemented in a concurrency safe
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// way. Blocking occurs at the expense of total performance of rendering
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// all registered metrics. Ideally, Collector implementations support
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// concurrent readers.
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Collect(chan<- Metric)
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}
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// selfCollector implements Collector for a single Metric so that the Metric
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// collects itself. Add it as an anonymous field to a struct that implements
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// Metric, and call init with the Metric itself as an argument.
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type selfCollector struct {
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self Metric
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}
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// init provides the selfCollector with a reference to the metric it is supposed
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// to collect. It is usually called within the factory function to create a
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// metric. See example.
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func (c *selfCollector) init(self Metric) {
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c.self = self
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}
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// Describe implements Collector.
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func (c *selfCollector) Describe(ch chan<- *Desc) {
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ch <- c.self.Desc()
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}
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// Collect implements Collector.
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func (c *selfCollector) Collect(ch chan<- Metric) {
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ch <- c.self
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}
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