Add option to disable STATS SETTINGS

In order to support mcrouter, add a flag to disable the collection of "STATS SETTINGS". Fixes: #113 Signed-off-by: SuperQ <[email protected]>
prometheus · Jan 10, 2022 · 8b4b5a4 · 8b4b5a4
1 parent 2458f73
commit 8b4b5a4
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Showing 4 changed files with 29 additions and 14 deletions.
diff --git a/README.md b/README.md
@@ -24,6 +24,14 @@ Alternatively a Dockerfile is supplied:
 docker run -p 9150:9150 quay.io/prometheus/memcached-exporter:latest
 ```
 
+## mcrouter
+
+In order to use the memcached_exporter with [mcrouter](https://github.com/facebook/mcrouter) the "STATS SETTINGS" collection needs to be disabled.
+
+```sh
+./memcached_exporter --no.memcached.stats.settings
+```
+
 ## Collectors
 
 The exporter collects a number of statistics from the server:

diff --git a/cmd/memcached_exporter/main.go b/cmd/memcached_exporter/main.go
@@ -36,6 +36,7 @@ func main() {
 		address       = kingpin.Flag("memcached.address", "Memcached server address.").Default("localhost:11211").String()
 		timeout       = kingpin.Flag("memcached.timeout", "memcached connect timeout.").Default("1s").Duration()
 		pidFile       = kingpin.Flag("memcached.pid-file", "Optional path to a file containing the memcached PID for additional metrics.").Default("").String()
+		getSettings   = kingpin.Flag("memcached.stats.settings", "Enable collection of STATS SETTINGS.").Default("true").Bool()
 		webConfig     = webflag.AddFlags(kingpin.CommandLine)
 		listenAddress = kingpin.Flag("web.listen-address", "Address to listen on for web interface and telemetry.").Default(":9150").String()
 		metricsPath   = kingpin.Flag("web.telemetry-path", "Path under which to expose metrics.").Default("/metrics").String()
@@ -51,7 +52,7 @@ func main() {
 	level.Info(logger).Log("msg", "Build context", "context", version.BuildContext())
 
 	prometheus.MustRegister(version.NewCollector("memcached_exporter"))
-	prometheus.MustRegister(exporter.New(*address, *timeout, logger))
+	prometheus.MustRegister(exporter.New(*address, *timeout, *getSettings, logger))
 
 	if *pidFile != "" {
 		procExporter := collectors.NewProcessCollector(collectors.ProcessCollectorOpts{

diff --git a/pkg/exporter/exporter.go b/pkg/exporter/exporter.go
@@ -40,6 +40,8 @@ type Exporter struct {
 	timeout time.Duration
 	logger  log.Logger
 
+	getSettings bool
+
 	up                       *prometheus.Desc
 	uptime                   *prometheus.Desc
 	time                     *prometheus.Desc
@@ -109,11 +111,12 @@ type Exporter struct {
 }
 
 // New returns an initialized exporter.
-func New(server string, timeout time.Duration, logger log.Logger) *Exporter {
+func New(server string, timeout time.Duration, getSettings bool, logger log.Logger) *Exporter {
 	return &Exporter{
-		address: server,
-		timeout: timeout,
-		logger:  logger,
+		address:     server,
+		timeout:     timeout,
+		logger:      logger,
+		getSettings: getSettings,
 		up: prometheus.NewDesc(
 			prometheus.BuildFQName(Namespace, "", "up"),
 			"Could the memcached server be reached.",
@@ -602,17 +605,20 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 		level.Error(e.logger).Log("msg", "Failed to collect stats from memcached", "err", err)
 		up = 0
 	}
-	statsSettings, err := c.StatsSettings()
-	if err != nil {
-		level.Error(e.logger).Log("msg", "Could not query stats settings", "err", err)
-		up = 0
-	}
 
 	if err := e.parseStats(ch, stats); err != nil {
 		up = 0
 	}
-	if err := e.parseStatsSettings(ch, statsSettings); err != nil {
-		up = 0
+
+	if e.getSettings {
+		statsSettings, err := c.StatsSettings()
+		if err != nil {
+			level.Error(e.logger).Log("msg", "Could not query stats settings", "err", err)
+			up = 0
+		}
+		if err := e.parseStatsSettings(ch, statsSettings); err != nil {
+			up = 0
+		}
 	}
 
 	ch <- prometheus.MustNewConstMetric(e.up, prometheus.GaugeValue, up)

diff --git a/pkg/exporter/exporter_test.go b/pkg/exporter/exporter_test.go
@@ -45,7 +45,7 @@ func TestParseStatsSettings(t *testing.T) {
 			},
 		}
 		ch := make(chan prometheus.Metric, 100)
-		e := New("", 100*time.Millisecond, log.NewNopLogger())
+		e := New("", 100*time.Millisecond, true, log.NewNopLogger())
 		if err := e.parseStatsSettings(ch, statsSettings); err != nil {
 			t.Errorf("expect return error, error: %v", err)
 		}
@@ -67,7 +67,7 @@ func TestParseStatsSettings(t *testing.T) {
 			},
 		}
 		ch := make(chan prometheus.Metric, 100)
-		e := New("", 100*time.Millisecond, log.NewNopLogger())
+		e := New("", 100*time.Millisecond, true, log.NewNopLogger())
 		if err := e.parseStatsSettings(ch, statsSettings); err == nil {
 			t.Error("expect return error but not")
 		}