HBASE-28837 Introduce row statistics coprocessor example (#6327)

Signed-off-by: Nick Dimiduk <ndimiduk@apache.org>
Co-authored-by: eab148 <54775485+eab148@users.noreply.github.com>
Co-authored-by: Evie Boland <eboland@hubspot.com>

Author: 3 people

hbase-examples/pom.xml

@@ -30,10 +30,6 @@
   <name>Apache HBase - Examples</name>
   <description>Examples of HBase usage</description>
   <dependencies>
-    <dependency>
-      <groupId>org.apache.hbase.thirdparty</groupId>
-      <artifactId>hbase-shaded-miscellaneous</artifactId>
-    </dependency>
     <dependency>
       <groupId>org.apache.hbase.thirdparty</groupId>
       <artifactId>hbase-shaded-netty</artifactId>
@@ -46,6 +42,27 @@
       <groupId>org.apache.hbase</groupId>
       <artifactId>hbase-protocol</artifactId>
     </dependency>
+    <dependency>
+      <groupId>org.apache.hbase.thirdparty</groupId>
+      <artifactId>hbase-shaded-miscellaneous</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>com.lmax</groupId>
+      <artifactId>disruptor</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-1.2-api</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.commons</groupId>
+      <artifactId>commons-lang3</artifactId>
+    </dependency>
     <dependency>
       <groupId>org.apache.hbase</groupId>
       <artifactId>hbase-logging</artifactId>
@@ -99,10 +116,6 @@
       <groupId>commons-io</groupId>
       <artifactId>commons-io</artifactId>
     </dependency>
-    <dependency>
-      <groupId>org.slf4j</groupId>
-      <artifactId>slf4j-api</artifactId>
-    </dependency>
     <dependency>
       <groupId>org.apache.zookeeper</groupId>
       <artifactId>zookeeper</artifactId>

hbase-examples/src/main/java/org/apache/hadoop/hbase/coprocessor/example/row/stats/RowStatistics.java

@@ -0,0 +1,62 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.coprocessor.example.row.stats;
+
+import java.util.Map;
+import org.apache.yetus.audience.InterfaceAudience;
+
+@InterfaceAudience.Private
+public interface RowStatistics {
+  String getTable();
+
+  String getRegion();
+
+  String getColumnFamily();
+
+  boolean isMajor();
+
+  long getLargestRowNumBytes();
+
+  int getLargestRowCellsCount();
+
+  long getLargestCellNumBytes();
+
+  int getCellsLargerThanOneBlockCount();
+
+  int getRowsLargerThanOneBlockCount();
+
+  int getCellsLargerThanMaxCacheSizeCount();
+
+  int getTotalDeletesCount();
+
+  int getTotalCellsCount();
+
+  int getTotalRowsCount();
+
+  long getTotalBytes();
+
+  String getLargestRowAsString();
+
+  String getLargestCellAsString();
+
+  Map<String, Long> getRowSizeBuckets();
+
+  Map<String, Long> getValueSizeBuckets();
+
+  String getJsonString();
+}