prometheus/metrics: three new metrics for consensus (#4263)

* prometheus/metrics: two new metrics for consensus

- add consensus_validator_power metric so if a node is a validator it can see its own power in prometheus
- add last_signed_height metric so if a node is a validator it can be aware of at which height the most recent time it signed.

- closes: #3773
- closes: #3083

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

* check if signature is present

* minor change and check if sig is not absent

* add changelog entry

* Update consensus/state.go

Co-Authored-By: Anton Kaliaev <anton.kalyaev@gmail.com>

* Update CHANGELOG_PENDING.md

Co-Authored-By: Anton Kaliaev <anton.kalyaev@gmail.com>

* Update CHANGELOG_PENDING.md

* add label with validator address

* change address to vali_address

* add metric missed blocks

* add changelog entry for missed blocks metric

* address naming & add docs

consensus/metrics.go

@@ -19,6 +19,9 @@ type Metrics struct {
 	// Height of the chain.
 	Height metrics.Gauge
 
+	// ValidatorLastSignedHeight of a validator.
+	ValidatorLastSignedHeight metrics.Gauge
+
 	// Number of rounds.
 	Rounds metrics.Gauge
 
@@ -26,6 +29,10 @@ type Metrics struct {
 	Validators metrics.Gauge
 	// Total power of all validators.
 	ValidatorsPower metrics.Gauge
+	// Power of a validator.
+	ValidatorPower metrics.Gauge
+	// Amount of blocks missed by a validator.
+	ValidatorMissedBlocks metrics.Gauge
 	// Number of validators who did not sign.
 	MissingValidators metrics.Gauge
 	// Total power of the missing validators.
@@ -81,12 +88,30 @@ func PrometheusMetrics(namespace string, labelsAndValues ...string) *Metrics {
 			Name:      "validators",
 			Help:      "Number of validators.",
 		}, labels).With(labelsAndValues...),
+		ValidatorLastSignedHeight: prometheus.NewGaugeFrom(stdprometheus.GaugeOpts{
+			Namespace: namespace,
+			Subsystem: MetricsSubsystem,
+			Name:      "validator_last_signed_height",
+			Help:      "Last signed height for a validator",
+		}, append(labels, "validator_address")).With(labelsAndValues...),
+		ValidatorMissedBlocks: prometheus.NewGaugeFrom(stdprometheus.GaugeOpts{
+			Namespace: namespace,
+			Subsystem: MetricsSubsystem,
+			Name:      "validator_missed_blocks",
+			Help:      "Total missed blocks for a validator",
+		}, append(labels, "validator_address")).With(labelsAndValues...),
 		ValidatorsPower: prometheus.NewGaugeFrom(stdprometheus.GaugeOpts{
 			Namespace: namespace,
 			Subsystem: MetricsSubsystem,
 			Name:      "validators_power",
 			Help:      "Total power of all validators.",
 		}, labels).With(labelsAndValues...),
+		ValidatorPower: prometheus.NewGaugeFrom(stdprometheus.GaugeOpts{
+			Namespace: namespace,
+			Subsystem: MetricsSubsystem,
+			Name:      "validator_power",
+			Help:      "Power of a validator",
+		}, append(labels, "validator_address")).With(labelsAndValues...),
 		MissingValidators: prometheus.NewGaugeFrom(stdprometheus.GaugeOpts{
 			Namespace: namespace,
 			Subsystem: MetricsSubsystem,
@@ -163,10 +188,14 @@ func NopMetrics() *Metrics {
 	return &Metrics{
 		Height: discard.NewGauge(),
 
+		ValidatorLastSignedHeight: discard.NewGauge(),
+
 		Rounds: discard.NewGauge(),
 
 		Validators:               discard.NewGauge(),
 		ValidatorsPower:          discard.NewGauge(),
+		ValidatorPower:           discard.NewGauge(),
+		ValidatorMissedBlocks:    discard.NewGauge(),
 		MissingValidators:        discard.NewGauge(),
 		MissingValidatorsPower:   discard.NewGauge(),
 		ByzantineValidators:      discard.NewGauge(),

consensus/state.go

@@ -1486,6 +1486,19 @@ func (cs *State) recordMetrics(height int64, block *types.Block) {
 
 		for i, val := range cs.LastValidators.Validators {
 			commitSig := block.LastCommit.Signatures[i]
+			privValAddress := cs.privValidator.GetPubKey().Address()
+			if cs.privValidator != nil && bytes.Equal(val.Address, privValAddress) {
+				label := []string{
+					"validator_address", privValAddress.String(),
+				}
+				cs.metrics.ValidatorPower.With(label...).Set(float64(val.VotingPower))
+				if !commitSig.Absent() {
+					cs.metrics.ValidatorLastSignedHeight.With(label...).Set(float64(height))
+				} else {
+					cs.metrics.ValidatorMissedBlocks.With(label...).Add(float64(1))
+				}
+			}
+
 			if commitSig.Absent() {
 				missingValidators++
 				missingValidatorsPower += val.VotingPower