Expose xDS updates metrics for library clients #8234
Description
Hi, how can I get xDS updates metrics?
I am interested in monitoring xDS updates frequency to our service and noticed there was metrics recorder added in this PR #8038.
I don't understand is how I can provide my own metrics recorder implementation and get those metrics.
What I ended up doing is fetching the resolver and wrapping it together with metrics recorder.
base := resolver.Get("xds")
resolver.Register(wrappedResolver{baseResolver: base, context: ctx, recordUpdate: recordUpdate})
type wrappedResolver struct {
baseResolver resolver.Builder
recordUpdate metricRecorderFunc
}
func (r wrappedResolver) Build(target resolver.Target, cc resolver.ClientConn,
opts resolver.BuildOptions) (resolver.Resolver, error) {
opts.MetricsRecorder = wrappedMetricsRecorder{
base: opts.MetricsRecorder,
recordUpdate: r.recordUpdate,
}
return r.baseResolver.Build(target, cc, opts)
}
func (r wrappedResolver) Scheme() string {
return r.baseResolver.Scheme()
}
type metricRecorderFunc func(ctx context.Context, incr int64, name string)
type wrappedMetricsRecorder struct {
base stats.MetricsRecorder
recordUpdate metricRecorderFunc
}
func (w wrappedMetricsRecorder) RecordInt64Count(handle *stats.Int64CountHandle, incr int64, labels ...string) {
if w.base != nil {
w.base.RecordInt64Count(handle, incr, labels...)
}
w.recordUpdate(incr, handle.Name)
}
func (w wrappedMetricsRecorder) RecordFloat64Count(handle *stats.Float64CountHandle, incr float64, labels ...string) {
if w.base != nil {
w.base.RecordFloat64Count(handle, incr, labels...)
}
}
func (w wrappedMetricsRecorder) RecordInt64Histo(handle *stats.Int64HistoHandle, incr int64, labels ...string) {
if w.base != nil {
w.base.RecordInt64Histo(handle, incr, labels...)
}
}
func (w wrappedMetricsRecorder) RecordFloat64Histo(handle *stats.Float64HistoHandle, incr float64, labels ...string) {
if w.base != nil {
w.base.RecordFloat64Histo(handle, incr, labels...)
}
}
func (w wrappedMetricsRecorder) RecordInt64Gauge(handle *stats.Int64GaugeHandle, incr int64, labels ...string) {
if w.base != nil {
w.base.RecordInt64Gauge(handle, incr, labels...)
}
}
We use GCP Cloud Service Mesh (Traffic Director) if that matters.