Druid metrics are getting interrupted if the graphite docker was restarted. If we restart druid dockers, then we are able to see the metrics again.
2019-02-21T22:04:01,127 ERROR [GraphiteEmitter-1] io.druid.emitter.graphite.GraphiteEmitter - Broken pipe (Write failed)
java.net.SocketException: Broken pipe (Write failed)
at java.net.SocketOutputStream.socketWrite0(Native Method) ~[?:1.8.0_151]
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:111) ~[?:1.8.0_151]
at java.net.SocketOutputStream.write(SocketOutputStream.java:143) ~[?:1.8.0_151]
at com.codahale.metrics.graphite.PickledGraphite.writeMetrics(PickledGraphite.java:262) ~[metrics-graphite-3.1.2.jar:3.1.2]
at com.codahale.metrics.graphite.PickledGraphite.flush(PickledGraphite.java:221) ~[metrics-graphite-3.1.2.jar:3.1.2]
at io.druid.emitter.graphite.GraphiteEmitter$ConsumerRunnable.run(GraphiteEmitter.java:176) [graphite-emitter-0.9.1.1.jar:0.9.1.1]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_151]
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) [?:1.8.0_151]
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) [?:1.8.0_151]
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) [?:1.8.0_151]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_151]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_151]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_151]