This removes the config and code to output to statsd.
- Change `cmd.StatsAndLogging` to output a `Scope`, not a `Statter`.
- Remove the prefixing of component name (e.g. "VA") in front of stats; this was stripped by `autoProm` but now no longer needs to be.
- Delete vendored statsd client.
- Delete `MockStatter` (generated by gomock) and `mocks.Statter` (hand generated) in favor of mocking `metrics.Scope`, which is the interface we now use everywhere.
- Remove a few unused methods on `metrics.Scope`, and update its generated mock.
- Refactor `autoProm` and add `autoRegisterer`, which can be included in a `metrics.Scope`, avoiding global state. `autoProm` now registers everything with the `prometheus.Registerer` it is given.
- Change va_test.go's `setup()` to not return a stats object; instead the individual tests that care about stats override `va.stats` directly.
Fixes#2639, #2733.
We have a number of stats already expressed using the statsd interface. During
the switchover period to direct Prometheus collection, we'd like to make those
stats available both ways. This change automatically exports any stats exported
using the statsd interface via Prometheus as well.
This is a little tricky because Prometheus expects all stats to by registered
exactly once. Prometheus does offer a mechanism to gracefully recover from
registering a stat more than once by handling a certain error, but it is not
safe for concurrent access. So I added a concurrency-safe wrapper that creates
Prometheus stats on demand and memoizes them.
In the process, made a few small required side changes:
- Clean "/" from method names in the gRPC interceptors. They are allowed in
statsd but not in Prometheus.
- Replace "127.0.0.1" with "boulder" as the name of our testing CT log.
Prometheus stats can't start with a number.
- Remove ":" from the CT-log stat names emitted by Publisher. Prometheus stats
can't include it.
- Remove a stray "RA" in front of some rate limit stats, since it was
duplicative (we were emitting "RA.RA..." before).
Note that this means two stat groups in particular are duplicated:
- Gostats* is duplicated with the default process-level stats exported by the
Prometheus library.
- gRPCClient* are duplicated by the stats generated by the go-grpc-prometheus
package.
When writing dashboards and alerts in the Prometheus world, we should be careful
to avoid these two categories, as they will disappear eventually. As a general
rule, if a stat is available with an all-lowercase name, choose that one, as it
is probably the Prometheus-native version.
In the long run we will want to create most stats using the native Prometheus
stat interface, since it allows us to use add labels to metrics, which is very
useful. For instance, currently our DNS stats distinguish types of queries by
appending the type to the stat name. This would be more natural as a label in
Prometheus.
Adds a server side unary RPC interceptor which includes basic stats. We could also use this to add a server request ID to the context.Context to identify the call through the system, but really I'd rather do that on the client side before the RPC is sent which requires the client interceptor implementation upstream. Also updates google.golang.org/grpc.
Updates #1880.
Jacob Hoffman-Andrews
Daniel
Daniel McCarney
Roland Bracewell Shoemaker
Jeff Hodges