exporter/prometheusexporter: migrate code in here #479
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@@ Coverage Diff @@
## master #479 +/- ##
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+ Coverage 57.02% 58.43% +1.4%
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Files 69 71 +2
Lines 4247 4439 +192
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+ Hits 2422 2594 +172
- Misses 1666 1682 +16
- Partials 159 163 +4
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Hand over prometheus exporter code that I had parked in https://github.com/orijtech/prometheus-go-metrics-exporter That code was written for OpenCensus Authors, and was just waiting for a final destination. This change finishes that. Fixes #478
Bring in sanitize_test.go from OpenCensus-Go.
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Thank you for the review @pjanotti! I've addressed your feedback, PTAL. |
| buckets := make([]float64, 0, len(dValue.Buckets)) | ||
| for index, bucket := range dBuckets { | ||
| if _, added := indicesMap[bucket]; !added { | ||
| indicesMap[bucket] = index |
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| points := make(map[float64]uint64, len(buckets)) | ||
| for _, bucket := range buckets { | ||
| index := indicesMap[bucket] |
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Same here, I don't think the reverse lookup is necessary.
| buckets := make([]float64, 0, len(dValue.Buckets)) | ||
| for index, bucket := range dBuckets { | ||
| if _, added := indicesMap[bucket]; !added { | ||
| indicesMap[bucket] = index |
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No question that for the Prometheus API used here the histograms need to be cumulative. This is not about making it cumulative for Prometheus but how far we go to support data that is malformed. Giving that code in the service should be in charge of converting to proto before this point it seems that the code gives support to bad receivers.
| Count: 1, | ||
| Sum: 11.9, | ||
| SumOfSquaredDeviation: 0, | ||
| Buckets: []*metricspb.DistributionValue_Bucket{ |
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Per proto spec this is not valid proto: you should have one more entry in the Buckets field then what you have on the Bounds
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| func (c *collector) Describe(ch chan<- *prometheus.Desc) { | ||
| c.registeredMetricsMu.Lock() | ||
| registered := make(map[string]*prometheus.Desc) |
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nit: map capacity hint, yes, it is just a hint but one expects the standard library to take advantage of that (otherwise why implement it :)
allocate the map outside the lock
| } | ||
| } | ||
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| var _ http.Handler = (*Exporter)(nil) |
| return desc, signature, ok | ||
| } | ||
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| func (c *collector) registerMetrics(metrics ...*metricspb.Metric) error { |
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nit: the only usage of this function passes a single *metricspb.Metric so there is no need for the variadic argument.
nit: on the usage site of registerMetrics is always rebuilds the signature, consider returning it.
| protoLabelKeysToLabels(metric.GetMetricDescriptor().GetLabelKeys()), | ||
| c.opts.ConstLabels, | ||
| ) | ||
| c.registeredMetricsMu.Lock() |
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Most of the time we the lookup above should succeed, putting that together with the copy that needs to happen from time to time, it seems that a reader-writer mutex will be more appropriate.
| return nil, err | ||
| } | ||
| derivedPrometheusValueType := prometheusValueType(metric) | ||
| desc, _, _ := c.lookupPrometheusDesc(c.opts.Namespace, metric) |
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Is it guaranteed that the metric signature was already added?
| func (c *collector) ensureRegisteredOnce() error { | ||
| var finalErr error | ||
| c.registerOnce.Do(func() { | ||
| if err := c.registry.Register(c); err != nil { |
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q.: are the costs of simply registering at construction too high? what are the downsides if registered and no metric ever registered?
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Please migrate the code to https://github.com/census-ecosystem/opencensus-go-exporter-prometheus instead.
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Sorry for the late reply @songy23! I have been swamped with work. Sure we can definitely move it over there but I'll get free cycles perhaps in the next 36 hours to move that over to the new repo. I shall close this PR and add an action item for myself. |
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No worries, I filed census-ecosystem/opencensus-go-exporter-prometheus#11 to keep track of that. |
Hand over prometheus exporter code that I had parked
in https://github.com/orijtech/prometheus-go-metrics-exporter
That code was written for OpenCensus Authors, and was just
waiting for a final destination. This change finishes that.
Fixes #478