From ac190e807739ccf5ae2236b8d39c342d23630358 Mon Sep 17 00:00:00 2001
From: stack <stack@apache.org>
Date: Tue, 7 Apr 2015 17:07:39 -0700
Subject: [PATCH] HBASE-13377 Canary may generate false alarm on the first
 region when there are many delete markers (He Liangliang)

Amending-Author: Andrew Purtell <apurtell@apache.org>

Conflicts:
	hbase-server/src/main/java/org/apache/hadoop/hbase/tool/Canary.java
---
 .../src/main/java/org/apache/hadoop/hbase/tool/Canary.java  | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/Canary.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/Canary.java
index 625828f2510..1dfe115512a 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/Canary.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/Canary.java
@@ -56,6 +56,7 @@ import org.apache.hadoop.hbase.client.RegionLocator;
 import org.apache.hadoop.hbase.client.ResultScanner;
 import org.apache.hadoop.hbase.client.Scan;
 import org.apache.hadoop.hbase.client.Table;
+import org.apache.hadoop.hbase.filter.FirstKeyOnlyFilter;
 import org.apache.hadoop.util.Tool;
 import org.apache.hadoop.util.ToolRunner;
 
@@ -551,10 +552,15 @@ public final class Canary implements Tool {
       // Can't do a get on empty start row so do a Scan of first element if any instead.
       if (startKey.length > 0) {
         get = new Get(startKey);
+        get.setCacheBlocks(false);
+        get.setFilter(new FirstKeyOnlyFilter());
         get.addFamily(column.getName());
       } else {
         scan = new Scan();
+        scan.setRaw(true);
         scan.setCaching(1);
+        scan.setCacheBlocks(false);
+        scan.setFilter(new FirstKeyOnlyFilter());
         scan.addFamily(column.getName());
         scan.setMaxResultSize(1L);
       }