diff options
author | Niall Sheridan <nsheridan@gmail.com> | 2018-06-20 22:39:07 +0100 |
---|---|---|
committer | Niall Sheridan <nsheridan@gmail.com> | 2018-06-20 22:39:07 +0100 |
commit | de6d2c524430287c699aaa898c1325da6afea539 (patch) | |
tree | f78eb841208d667668a7bc92a9290d693cc7103b /vendor/github.com/prometheus/client_golang/prometheus/registry.go | |
parent | eb99016e1629e690e55633de6fc63a14c53e7ea2 (diff) |
Update dependencies
Diffstat (limited to 'vendor/github.com/prometheus/client_golang/prometheus/registry.go')
-rw-r--r-- | vendor/github.com/prometheus/client_golang/prometheus/registry.go | 351 |
1 files changed, 193 insertions, 158 deletions
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/registry.go b/vendor/github.com/prometheus/client_golang/prometheus/registry.go index c84a442..fdb7bad 100644 --- a/vendor/github.com/prometheus/client_golang/prometheus/registry.go +++ b/vendor/github.com/prometheus/client_golang/prometheus/registry.go @@ -18,6 +18,7 @@ import ( "errors" "fmt" "os" + "runtime" "sort" "sync" "unicode/utf8" @@ -36,13 +37,14 @@ const ( // DefaultRegisterer and DefaultGatherer are the implementations of the // Registerer and Gatherer interface a number of convenience functions in this // package act on. Initially, both variables point to the same Registry, which -// has a process collector (see NewProcessCollector) and a Go collector (see -// NewGoCollector) already registered. This approach to keep default instances -// as global state mirrors the approach of other packages in the Go standard -// library. Note that there are caveats. Change the variables with caution and -// only if you understand the consequences. Users who want to avoid global state -// altogether should not use the convenience function and act on custom -// instances instead. +// has a process collector (currently on Linux only, see NewProcessCollector) +// and a Go collector (see NewGoCollector, in particular the note about +// stop-the-world implication with Go versions older than 1.9) already +// registered. This approach to keep default instances as global state mirrors +// the approach of other packages in the Go standard library. Note that there +// are caveats. Change the variables with caution and only if you understand the +// consequences. Users who want to avoid global state altogether should not use +// the convenience functions and act on custom instances instead. var ( defaultRegistry = NewRegistry() DefaultRegisterer Registerer = defaultRegistry @@ -124,15 +126,23 @@ type Registerer interface { type Gatherer interface { // Gather calls the Collect method of the registered Collectors and then // gathers the collected metrics into a lexicographically sorted slice - // of MetricFamily protobufs. Even if an error occurs, Gather attempts - // to gather as many metrics as possible. Hence, if a non-nil error is - // returned, the returned MetricFamily slice could be nil (in case of a - // fatal error that prevented any meaningful metric collection) or - // contain a number of MetricFamily protobufs, some of which might be - // incomplete, and some might be missing altogether. The returned error - // (which might be a MultiError) explains the details. In scenarios - // where complete collection is critical, the returned MetricFamily - // protobufs should be disregarded if the returned error is non-nil. + // of uniquely named MetricFamily protobufs. Gather ensures that the + // returned slice is valid and self-consistent so that it can be used + // for valid exposition. As an exception to the strict consistency + // requirements described for metric.Desc, Gather will tolerate + // different sets of label names for metrics of the same metric family. + // + // Even if an error occurs, Gather attempts to gather as many metrics as + // possible. Hence, if a non-nil error is returned, the returned + // MetricFamily slice could be nil (in case of a fatal error that + // prevented any meaningful metric collection) or contain a number of + // MetricFamily protobufs, some of which might be incomplete, and some + // might be missing altogether. The returned error (which might be a + // MultiError) explains the details. Note that this is mostly useful for + // debugging purposes. If the gathered protobufs are to be used for + // exposition in actual monitoring, it is almost always better to not + // expose an incomplete result and instead disregard the returned + // MetricFamily protobufs in case the returned error is non-nil. Gather() ([]*dto.MetricFamily, error) } @@ -202,6 +212,13 @@ func (errs MultiError) Error() string { return buf.String() } +// Append appends the provided error if it is not nil. +func (errs *MultiError) Append(err error) { + if err != nil { + *errs = append(*errs, err) + } +} + // MaybeUnwrap returns nil if len(errs) is 0. It returns the first and only // contained error as error if len(errs is 1). In all other cases, it returns // the MultiError directly. This is helpful for returning a MultiError in a way @@ -361,29 +378,18 @@ func (r *Registry) Gather() ([]*dto.MetricFamily, error) { var ( metricChan = make(chan Metric, capMetricChan) metricHashes = map[uint64]struct{}{} - dimHashes = map[string]uint64{} wg sync.WaitGroup errs MultiError // The collected errors to return in the end. registeredDescIDs map[uint64]struct{} // Only used for pedantic checks ) r.mtx.RLock() + goroutineBudget := len(r.collectorsByID) metricFamiliesByName := make(map[string]*dto.MetricFamily, len(r.dimHashesByName)) - - // Scatter. - // (Collectors could be complex and slow, so we call them all at once.) - wg.Add(len(r.collectorsByID)) - go func() { - wg.Wait() - close(metricChan) - }() + collectors := make(chan Collector, len(r.collectorsByID)) for _, collector := range r.collectorsByID { - go func(collector Collector) { - defer wg.Done() - collector.Collect(metricChan) - }(collector) + collectors <- collector } - // In case pedantic checks are enabled, we have to copy the map before // giving up the RLock. if r.pedanticChecksEnabled { @@ -392,127 +398,173 @@ func (r *Registry) Gather() ([]*dto.MetricFamily, error) { registeredDescIDs[id] = struct{}{} } } - r.mtx.RUnlock() + wg.Add(goroutineBudget) + + collectWorker := func() { + for { + select { + case collector := <-collectors: + collector.Collect(metricChan) + wg.Done() + default: + return + } + } + } + + // Start the first worker now to make sure at least one is running. + go collectWorker() + goroutineBudget-- + + // Close the metricChan once all collectors are collected. + go func() { + wg.Wait() + close(metricChan) + }() + // Drain metricChan in case of premature return. defer func() { for range metricChan { } }() - // Gather. - for metric := range metricChan { - // This could be done concurrently, too, but it required locking - // of metricFamiliesByName (and of metricHashes if checks are - // enabled). Most likely not worth it. - desc := metric.Desc() - dtoMetric := &dto.Metric{} - if err := metric.Write(dtoMetric); err != nil { - errs = append(errs, fmt.Errorf( - "error collecting metric %v: %s", desc, err, - )) - continue - } - metricFamily, ok := metricFamiliesByName[desc.fqName] - if ok { - if metricFamily.GetHelp() != desc.help { - errs = append(errs, fmt.Errorf( - "collected metric %s %s has help %q but should have %q", - desc.fqName, dtoMetric, desc.help, metricFamily.GetHelp(), - )) - continue +collectLoop: + for { + select { + case metric, ok := <-metricChan: + if !ok { + // metricChan is closed, we are done. + break collectLoop } - // TODO(beorn7): Simplify switch once Desc has type. - switch metricFamily.GetType() { - case dto.MetricType_COUNTER: - if dtoMetric.Counter == nil { - errs = append(errs, fmt.Errorf( - "collected metric %s %s should be a Counter", - desc.fqName, dtoMetric, - )) - continue - } - case dto.MetricType_GAUGE: - if dtoMetric.Gauge == nil { - errs = append(errs, fmt.Errorf( - "collected metric %s %s should be a Gauge", - desc.fqName, dtoMetric, - )) - continue - } - case dto.MetricType_SUMMARY: - if dtoMetric.Summary == nil { - errs = append(errs, fmt.Errorf( - "collected metric %s %s should be a Summary", - desc.fqName, dtoMetric, - )) - continue - } - case dto.MetricType_UNTYPED: - if dtoMetric.Untyped == nil { - errs = append(errs, fmt.Errorf( - "collected metric %s %s should be Untyped", - desc.fqName, dtoMetric, - )) - continue - } - case dto.MetricType_HISTOGRAM: - if dtoMetric.Histogram == nil { - errs = append(errs, fmt.Errorf( - "collected metric %s %s should be a Histogram", - desc.fqName, dtoMetric, + errs.Append(processMetric( + metric, metricFamiliesByName, + metricHashes, + registeredDescIDs, + )) + default: + if goroutineBudget <= 0 || len(collectors) == 0 { + // All collectors are already being worked on or + // we have already as many goroutines started as + // there are collectors. Just process metrics + // from now on. + for metric := range metricChan { + errs.Append(processMetric( + metric, metricFamiliesByName, + metricHashes, + registeredDescIDs, )) - continue } - default: - panic("encountered MetricFamily with invalid type") - } - } else { - metricFamily = &dto.MetricFamily{} - metricFamily.Name = proto.String(desc.fqName) - metricFamily.Help = proto.String(desc.help) - // TODO(beorn7): Simplify switch once Desc has type. - switch { - case dtoMetric.Gauge != nil: - metricFamily.Type = dto.MetricType_GAUGE.Enum() - case dtoMetric.Counter != nil: - metricFamily.Type = dto.MetricType_COUNTER.Enum() - case dtoMetric.Summary != nil: - metricFamily.Type = dto.MetricType_SUMMARY.Enum() - case dtoMetric.Untyped != nil: - metricFamily.Type = dto.MetricType_UNTYPED.Enum() - case dtoMetric.Histogram != nil: - metricFamily.Type = dto.MetricType_HISTOGRAM.Enum() - default: - errs = append(errs, fmt.Errorf( - "empty metric collected: %s", dtoMetric, - )) - continue + break collectLoop } - metricFamiliesByName[desc.fqName] = metricFamily + // Start more workers. + go collectWorker() + goroutineBudget-- + runtime.Gosched() } - if err := checkMetricConsistency(metricFamily, dtoMetric, metricHashes, dimHashes); err != nil { - errs = append(errs, err) - continue + } + return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap() +} + +// processMetric is an internal helper method only used by the Gather method. +func processMetric( + metric Metric, + metricFamiliesByName map[string]*dto.MetricFamily, + metricHashes map[uint64]struct{}, + registeredDescIDs map[uint64]struct{}, +) error { + desc := metric.Desc() + dtoMetric := &dto.Metric{} + if err := metric.Write(dtoMetric); err != nil { + return fmt.Errorf("error collecting metric %v: %s", desc, err) + } + metricFamily, ok := metricFamiliesByName[desc.fqName] + if ok { + if metricFamily.GetHelp() != desc.help { + return fmt.Errorf( + "collected metric %s %s has help %q but should have %q", + desc.fqName, dtoMetric, desc.help, metricFamily.GetHelp(), + ) } - if r.pedanticChecksEnabled { - // Is the desc registered at all? - if _, exist := registeredDescIDs[desc.id]; !exist { - errs = append(errs, fmt.Errorf( - "collected metric %s %s with unregistered descriptor %s", - metricFamily.GetName(), dtoMetric, desc, - )) - continue + // TODO(beorn7): Simplify switch once Desc has type. + switch metricFamily.GetType() { + case dto.MetricType_COUNTER: + if dtoMetric.Counter == nil { + return fmt.Errorf( + "collected metric %s %s should be a Counter", + desc.fqName, dtoMetric, + ) + } + case dto.MetricType_GAUGE: + if dtoMetric.Gauge == nil { + return fmt.Errorf( + "collected metric %s %s should be a Gauge", + desc.fqName, dtoMetric, + ) } - if err := checkDescConsistency(metricFamily, dtoMetric, desc); err != nil { - errs = append(errs, err) - continue + case dto.MetricType_SUMMARY: + if dtoMetric.Summary == nil { + return fmt.Errorf( + "collected metric %s %s should be a Summary", + desc.fqName, dtoMetric, + ) } + case dto.MetricType_UNTYPED: + if dtoMetric.Untyped == nil { + return fmt.Errorf( + "collected metric %s %s should be Untyped", + desc.fqName, dtoMetric, + ) + } + case dto.MetricType_HISTOGRAM: + if dtoMetric.Histogram == nil { + return fmt.Errorf( + "collected metric %s %s should be a Histogram", + desc.fqName, dtoMetric, + ) + } + default: + panic("encountered MetricFamily with invalid type") } - metricFamily.Metric = append(metricFamily.Metric, dtoMetric) + } else { + metricFamily = &dto.MetricFamily{} + metricFamily.Name = proto.String(desc.fqName) + metricFamily.Help = proto.String(desc.help) + // TODO(beorn7): Simplify switch once Desc has type. + switch { + case dtoMetric.Gauge != nil: + metricFamily.Type = dto.MetricType_GAUGE.Enum() + case dtoMetric.Counter != nil: + metricFamily.Type = dto.MetricType_COUNTER.Enum() + case dtoMetric.Summary != nil: + metricFamily.Type = dto.MetricType_SUMMARY.Enum() + case dtoMetric.Untyped != nil: + metricFamily.Type = dto.MetricType_UNTYPED.Enum() + case dtoMetric.Histogram != nil: + metricFamily.Type = dto.MetricType_HISTOGRAM.Enum() + default: + return fmt.Errorf("empty metric collected: %s", dtoMetric) + } + metricFamiliesByName[desc.fqName] = metricFamily } - return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap() + if err := checkMetricConsistency(metricFamily, dtoMetric, metricHashes); err != nil { + return err + } + if registeredDescIDs != nil { + // Is the desc registered at all? + if _, exist := registeredDescIDs[desc.id]; !exist { + return fmt.Errorf( + "collected metric %s %s with unregistered descriptor %s", + metricFamily.GetName(), dtoMetric, desc, + ) + } + if err := checkDescConsistency(metricFamily, dtoMetric, desc); err != nil { + return err + } + } + metricFamily.Metric = append(metricFamily.Metric, dtoMetric) + return nil } // Gatherers is a slice of Gatherer instances that implements the Gatherer @@ -538,7 +590,6 @@ func (gs Gatherers) Gather() ([]*dto.MetricFamily, error) { var ( metricFamiliesByName = map[string]*dto.MetricFamily{} metricHashes = map[uint64]struct{}{} - dimHashes = map[string]uint64{} errs MultiError // The collected errors to return in the end. ) @@ -578,7 +629,7 @@ func (gs Gatherers) Gather() ([]*dto.MetricFamily, error) { metricFamiliesByName[mf.GetName()] = existingMF } for _, m := range mf.Metric { - if err := checkMetricConsistency(existingMF, m, metricHashes, dimHashes); err != nil { + if err := checkMetricConsistency(existingMF, m, metricHashes); err != nil { errs = append(errs, err) continue } @@ -655,18 +706,13 @@ func normalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) } // checkMetricConsistency checks if the provided Metric is consistent with the -// provided MetricFamily. It also hashed the Metric labels and the MetricFamily +// provided MetricFamily. It also hashes the Metric labels and the MetricFamily // name. If the resulting hash is already in the provided metricHashes, an error -// is returned. If not, it is added to metricHashes. The provided dimHashes maps -// MetricFamily names to their dimHash (hashed sorted label names). If dimHashes -// doesn't yet contain a hash for the provided MetricFamily, it is -// added. Otherwise, an error is returned if the existing dimHashes in not equal -// the calculated dimHash. +// is returned. If not, it is added to metricHashes. func checkMetricConsistency( metricFamily *dto.MetricFamily, dtoMetric *dto.Metric, metricHashes map[uint64]struct{}, - dimHashes map[string]uint64, ) error { // Type consistency with metric family. if metricFamily.GetType() == dto.MetricType_GAUGE && dtoMetric.Gauge == nil || @@ -681,24 +727,23 @@ func checkMetricConsistency( } for _, labelPair := range dtoMetric.GetLabel() { - if !utf8.ValidString(*labelPair.Value) { - return fmt.Errorf("collected metric's label %s is not utf8: %#v", *labelPair.Name, *labelPair.Value) + if !utf8.ValidString(labelPair.GetValue()) { + return fmt.Errorf("collected metric's label %s is not utf8: %#v", labelPair.GetName(), labelPair.GetValue()) } } - // Is the metric unique (i.e. no other metric with the same name and the same label values)? + // Is the metric unique (i.e. no other metric with the same name and the same labels)? h := hashNew() h = hashAdd(h, metricFamily.GetName()) h = hashAddByte(h, separatorByte) - dh := hashNew() // Make sure label pairs are sorted. We depend on it for the consistency // check. sort.Sort(LabelPairSorter(dtoMetric.Label)) for _, lp := range dtoMetric.Label { + h = hashAdd(h, lp.GetName()) + h = hashAddByte(h, separatorByte) h = hashAdd(h, lp.GetValue()) h = hashAddByte(h, separatorByte) - dh = hashAdd(dh, lp.GetName()) - dh = hashAddByte(dh, separatorByte) } if _, exists := metricHashes[h]; exists { return fmt.Errorf( @@ -706,16 +751,6 @@ func checkMetricConsistency( metricFamily.GetName(), dtoMetric, ) } - if dimHash, ok := dimHashes[metricFamily.GetName()]; ok { - if dimHash != dh { - return fmt.Errorf( - "collected metric %s %s has label dimensions inconsistent with previously collected metrics in the same metric family", - metricFamily.GetName(), dtoMetric, - ) - } - } else { - dimHashes[metricFamily.GetName()] = dh - } metricHashes[h] = struct{}{} return nil } |