fix(exporter): handle pool sync time metrics collection gracefully (#…

…1616) This PR fixes a bug in pool sync time metrics collector in maya exporter. If last request is in progress, don't queue the current request during pool last Sync time metrics collection and increment the reject request counter. Signed-off-by: mittachaitu <[email protected]>
openebs-archive · Feb 26, 2020 · 9417d96 · 9417d96
1 parent 3ce311e
commit 9417d96
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diff --git a/cmd/maya-exporter/app/collector/zvol/metrics.go b/cmd/maya-exporter/app/collector/zvol/metrics.go
@@ -68,6 +68,7 @@ type poolSyncMetrics struct {
 	zpoolLastSyncTime             *prometheus.GaugeVec
 	zpoolStateUnknown             *prometheus.GaugeVec
 	zpoolLastSyncTimeCommandError *prometheus.GaugeVec
+	cspiRequestRejectCounter      prometheus.Counter
 }
 
 // poolfields struct is for pool last sync time metric
@@ -437,6 +438,17 @@ func (p *poolSyncMetrics) withZpoolStateUnknown() *poolSyncMetrics {
 	return p
 }
 
+func (p *poolSyncMetrics) withRequestRejectCounter() *poolSyncMetrics {
+	p.cspiRequestRejectCounter = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "openebs",
+			Name:      "zfs_get_livenesstimestamp_request_reject_count",
+			Help:      "Total no of rejected requests for pool liveness",
+		},
+	)
+	return p
+}
+
 func (p *poolSyncMetrics) withzpoolLastSyncTimeCommandError() *poolSyncMetrics {
 
 	p.zpoolLastSyncTimeCommandError = prometheus.NewGaugeVec(

diff --git a/cmd/maya-exporter/app/collector/zvol/pool_synctime.go b/cmd/maya-exporter/app/collector/zvol/pool_synctime.go
@@ -40,11 +40,16 @@ func NewPoolSyncMetric(runner types.Runner) col.Collector {
 		poolSyncMetrics: newPoolMetrics().
 			withZpoolLastSyncTime().
 			withZpoolStateUnknown().
+			withRequestRejectCounter().
 			withzpoolLastSyncTimeCommandError(),
 		runner: runner,
 	}
 }
 
+func (p *poolMetrics) isRequestInProgress() bool {
+	return p.request
+}
+
 func (p *poolMetrics) setRequestToFalse() {
 	p.Lock()
 	p.request = false
@@ -110,6 +115,12 @@ func (p *poolMetrics) get() *poolfields {
 // Collect is implementation of prometheus's prometheus.Collector interface
 func (p *poolMetrics) Collect(ch chan<- prometheus.Metric) {
 	p.Lock()
+	if p.isRequestInProgress() {
+		p.cspiRequestRejectCounter.Inc()
+		p.Unlock()
+		p.cspiRequestRejectCounter.Collect(ch)
+		return
+	}
 	p.request = true
 	p.Unlock()