From e1313e4b90bb434a33131a62c74abd52343f3f2e Mon Sep 17 00:00:00 2001
From: Himanshu <g.himanshu@gmail.com>
Date: Fri, 1 Jul 2016 17:35:30 -0500
Subject: [PATCH] add log msg when event recvr firehose buffer is full (#3209)

---
 .../realtime/firehose/EventReceiverFirehoseFactory.java  | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/server/src/main/java/io/druid/segment/realtime/firehose/EventReceiverFirehoseFactory.java b/server/src/main/java/io/druid/segment/realtime/firehose/EventReceiverFirehoseFactory.java
index 76322fc80bc..3f20139fd8e 100644
--- a/server/src/main/java/io/druid/segment/realtime/firehose/EventReceiverFirehoseFactory.java
+++ b/server/src/main/java/io/druid/segment/realtime/firehose/EventReceiverFirehoseFactory.java
@@ -57,7 +57,6 @@ import javax.ws.rs.core.Response;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Collection;
-import java.util.Date;
 import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
@@ -147,6 +146,7 @@ public class EventReceiverFirehoseFactory implements FirehoseFactory<MapInputRow
     private volatile InputRow nextRow = null;
     private volatile boolean closed = false;
     private final AtomicLong bytesReceived = new AtomicLong(0);
+    private final AtomicLong lastBufferAddFailMsgTime = new AtomicLong(0);
 
     public EventReceiverFirehose(MapInputRowParser parser)
     {
@@ -298,6 +298,13 @@ public class EventReceiverFirehoseFactory implements FirehoseFactory<MapInputRow
         boolean added = false;
         while (!closed && !added) {
           added = buffer.offer(row, 500, TimeUnit.MILLISECONDS);
+          if (!added) {
+            long currTime = System.currentTimeMillis();
+            long lastTime = lastBufferAddFailMsgTime.get();
+            if (currTime - lastTime > 10000 && lastBufferAddFailMsgTime.compareAndSet(lastTime, currTime)) {
+              log.warn("Failed to add event to buffer with current size [%s] . Retrying...", buffer.size());
+            }
+          }
         }
 
         if (!added) {