metric: disallow calls to Counter.Dec, use Gauge instead#21903
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nvb merged 1 commit intocockroachdb:masterfrom Jan 30, 2018
Merged
metric: disallow calls to Counter.Dec, use Gauge instead#21903nvb merged 1 commit intocockroachdb:masterfrom
nvb merged 1 commit intocockroachdb:masterfrom
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https://prometheus.io/docs/concepts/metric_types/#counter says that: > Counters should not be used to expose current counts of items > whose number can also go down, e.g. the number of currently > running goroutines. Use gauges for this use case. We were ignoring this in a few places. This change prevents the use of `Counter.Dec` and turns all previous users into Gauges. The change prevents use of `Counter.Dec` by overriding the method and making it panic with a message to "use a Gauge instead". An alternate approach would be to unembedded `metrics.Counter` and no longer expose a `Dec` method. That approach would also be ok, but I think this way does a better job documenting the issue, preventing regressions, and avoiding boilerplate required if `metrics.Counter` was unexported. Release note: None
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a-robinson
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LGTM. I should have checked for this a while ago.
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TFTR! |
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https://prometheus.io/docs/concepts/metric_types/#counter says that:
We were ignoring this in a few places. This change prevents the
use of
Counter.Decand turns all previous users into Gauges.The change prevents use of
Counter.Decby overriding the method andmaking it panic with a message to "use a Gauge instead". An alternate
approach would be to unembedded
metrics.Counterand no longer exposea
Decmethod. That approach would also be ok, but I think this waydoes a better job documenting the issue, preventing regressions, and
avoiding boilerplate required if
metrics.Counterwas unexported.Release note: None