Add Graphite backend configuration flag to connect only when there are metrics to send

backends/graphite.js

@@ -21,6 +21,8 @@ var net = require('net'),
 var l;
 
 var debug;
+var quiet = false;
+var deleteIdleStats = false;
 var flushInterval;
 var graphiteHost;
 var graphitePort;
@@ -98,6 +100,19 @@ var flush_stats = function graphite_flush(ts, metrics) {
   var timer_data = metrics.timer_data;
   var statsd_metrics = metrics.statsd_metrics;
 
+  if (quiet
+      && deleteIdleStats
+      && (counters === null || isEmptyObject(counters))
+      && (timer_data === null || isEmptyObject(timer_data))
+      && (gauges === null || isEmptyObject(gauges))
+      && (sets === null || isEmptyObject(sets))
+     ) {
+    if (debug) {
+      l.log("Not sending stats, no metrics to report");
+    }
+    return;
+  }
+
   for (key in counters) {
     var namespace = counterNamespace.concat(key);
     var value = counters[key];
@@ -190,14 +205,18 @@ exports.init = function graphite_init(startup_time, config, events) {
   prefixSet       = config.graphite.prefixSet;
   globalSuffix    = config.graphite.globalSuffix;
   legacyNamespace = config.graphite.legacyNamespace;
+  quiet           = config.graphite.quiet;
+  deleteIdleStats = config.deleteIdleStats;
 
   // set defaults for prefixes & suffix
-  globalPrefix  = globalPrefix !== undefined ? globalPrefix : "stats";
-  prefixCounter = prefixCounter !== undefined ? prefixCounter : "counters";
-  prefixTimer   = prefixTimer !== undefined ? prefixTimer : "timers";
-  prefixGauge   = prefixGauge !== undefined ? prefixGauge : "gauges";
-  prefixSet     = prefixSet !== undefined ? prefixSet : "sets";
+  globalPrefix    = globalPrefix !== undefined ? globalPrefix : "stats";
+  prefixCounter   = prefixCounter !== undefined ? prefixCounter : "counters";
+  prefixTimer     = prefixTimer !== undefined ? prefixTimer : "timers";
+  prefixGauge     = prefixGauge !== undefined ? prefixGauge : "gauges";
+  prefixSet       = prefixSet !== undefined ? prefixSet : "sets";
   legacyNamespace = legacyNamespace !== undefined ? legacyNamespace : true;
+  quiet           = quiet !== undefined ? quiet : false;
+  deleteIdleStats = deleteIdleStats !== undefined ? deleteIdleStats : false;
 
   // In order to unconditionally add this string, it either needs to be
   // a single space if it was unset, OR surrounded by a . and a space if
@@ -247,3 +266,10 @@ exports.init = function graphite_init(startup_time, config, events) {
 
   return true;
 };
+
+function isEmptyObject(obj) {
+  for (var name in obj) {
+    return false;
+  }
+  return true;
+}

exampleConfig.js

@@ -64,6 +64,8 @@ Optional Variables:
 
   graphite:
     legacyNamespace:  use the legacy namespace [default: true]
+    quiet:            connect to the Graphite server only when there are metrics to report
+                      AND deleteIdleStats is set to 'true' [default: false]
     globalPrefix:     global prefix to use for sending stats to graphite [default: "stats"]
     prefixCounter:    graphite prefix for counter metrics [default: "counters"]
     prefixTimer:      graphite prefix for timer metrics [default: "timers"]

test/graphite_tests.js

@@ -80,7 +80,8 @@ module.exports = {
                ,  port: 8125\n\
                ,  dumpMessages: false \n\
                ,  debug: false\n\
-               ,  graphite: { legacyNamespace: false }\n\
+               ,  deleteIdleStats: true\n\
+               ,  graphite: { legacyNamespace: false, quiet: true }\n\
                ,  graphitePort: " + this.testport + "\n\
                ,  graphiteHost: \"127.0.0.1\"}";