HBASE-24295 [Chaos Monkey] abstract logging through the class hierarchy

Adds `protected abstract Logger getLogger()` to `Action` so that
implementation's names are logged when actions are performed.

Signed-off-by: stack <stack@apache.org>
Signed-off-by: Jan Hentschel <jan.hentschel@ultratendency.com>

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/Action.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -50,12 +50,11 @@ import org.apache.hadoop.hbase.client.TableDescriptor;
 import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /**
  * A (possibly mischievous) action that the ChaosMonkey can perform.
  */
-public class Action {
+public abstract class Action {
 
   public static final String KILL_MASTER_TIMEOUT_KEY =
     "hbase.chaosmonkey.action.killmastertimeout";
@@ -76,8 +75,6 @@ public class Action {
   public static final String START_NAMENODE_TIMEOUT_KEY =
       "hbase.chaosmonkey.action.startnamenodetimeout";
 
-  private static final Logger LOG = LoggerFactory.getLogger(Action.class);
-
   protected static final long KILL_MASTER_TIMEOUT_DEFAULT = PolicyBasedChaosMonkey.TIMEOUT;
   protected static final long START_MASTER_TIMEOUT_DEFAULT = PolicyBasedChaosMonkey.TIMEOUT;
   protected static final long KILL_RS_TIMEOUT_DEFAULT = PolicyBasedChaosMonkey.TIMEOUT;
@@ -107,12 +104,17 @@ public class Action {
   protected long startNameNodeTimeout;
   protected boolean skipMetaRS;
 
+  /**
+   * Retrieve the instance's {@link Logger}, for use throughout the class hierarchy.
+   */
+  protected abstract Logger getLogger();
+
   public void init(ActionContext context) throws IOException {
     this.context = context;
     cluster = context.getHBaseCluster();
     initialStatus = cluster.getInitialClusterMetrics();
     Collection<ServerName> regionServers = initialStatus.getLiveServerMetrics().keySet();
-    initialServers = regionServers.toArray(new ServerName[regionServers.size()]);
+    initialServers = regionServers.toArray(new ServerName[0]);
 
     monkeyProps = context.getMonkeyProps();
     if (monkeyProps == null){
@@ -150,12 +152,12 @@ public class Action {
   protected ServerName[] getCurrentServers() throws IOException {
     ClusterMetrics clusterStatus = cluster.getClusterMetrics();
     Collection<ServerName> regionServers = clusterStatus.getLiveServerMetrics().keySet();
-    int count = regionServers == null ? 0 : regionServers.size();
+    int count = regionServers.size();
     if (count <= 0) {
       return new ServerName [] {};
     }
     ServerName master = clusterStatus.getMasterName();
-    Set<ServerName> masters = new HashSet<ServerName>();
+    Set<ServerName> masters = new HashSet<>();
     masters.add(master);
     masters.addAll(clusterStatus.getBackupMasterNames());
     ArrayList<ServerName> tmp = new ArrayList<>(count);
@@ -167,110 +169,110 @@ public class Action {
       tmp.remove(metaServer);
     }
 
-    return tmp.toArray(new ServerName[tmp.size()]);
+    return tmp.toArray(new ServerName[0]);
   }
 
   protected void killMaster(ServerName server) throws IOException {
-    LOG.info("Killing master {}", server);
+    getLogger().info("Killing master {}", server);
     cluster.killMaster(server);
     cluster.waitForMasterToStop(server, killMasterTimeout);
-    LOG.info("Killed master " + server);
+    getLogger().info("Killed master " + server);
   }
 
   protected void startMaster(ServerName server) throws IOException {
-    LOG.info("Starting master {}", server.getHostname());
+    getLogger().info("Starting master {}", server.getHostname());
     cluster.startMaster(server.getHostname(), server.getPort());
     cluster.waitForActiveAndReadyMaster(startMasterTimeout);
-    LOG.info("Started master " + server.getHostname());
+    getLogger().info("Started master " + server.getHostname());
   }
 
   protected void stopRs(ServerName server) throws IOException {
-    LOG.info("Stopping regionserver {}", server);
+    getLogger().info("Stopping regionserver {}", server);
     cluster.stopRegionServer(server);
     cluster.waitForRegionServerToStop(server, killRsTimeout);
-    LOG.info("Stoppiong regionserver {}. Reported num of rs:{}", server,
+    getLogger().info("Stoppiong regionserver {}. Reported num of rs:{}", server,
       cluster.getClusterMetrics().getLiveServerMetrics().size());
   }
 
   protected void suspendRs(ServerName server) throws IOException {
-    LOG.info("Suspending regionserver {}", server);
+    getLogger().info("Suspending regionserver {}", server);
     cluster.suspendRegionServer(server);
     if(!(cluster instanceof MiniHBaseCluster)){
       cluster.waitForRegionServerToStop(server, killRsTimeout);
     }
-    LOG.info("Suspending regionserver {}. Reported num of rs:{}", server,
+    getLogger().info("Suspending regionserver {}. Reported num of rs:{}", server,
       cluster.getClusterMetrics().getLiveServerMetrics().size());
   }
 
   protected void resumeRs(ServerName server) throws IOException {
-    LOG.info("Resuming regionserver {}", server);
+    getLogger().info("Resuming regionserver {}", server);
     cluster.resumeRegionServer(server);
     if(!(cluster instanceof MiniHBaseCluster)){
       cluster.waitForRegionServerToStart(server.getHostname(), server.getPort(), startRsTimeout);
     }
-    LOG.info("Resuming regionserver {}. Reported num of rs:{}", server,
+    getLogger().info("Resuming regionserver {}. Reported num of rs:{}", server,
       cluster.getClusterMetrics().getLiveServerMetrics().size());
   }
 
   protected void killRs(ServerName server) throws IOException {
-    LOG.info("Killing regionserver {}", server);
+    getLogger().info("Killing regionserver {}", server);
     cluster.killRegionServer(server);
     cluster.waitForRegionServerToStop(server, killRsTimeout);
-    LOG.info("Killed regionserver {}. Reported num of rs:{}", server,
+    getLogger().info("Killed regionserver {}. Reported num of rs:{}", server,
       cluster.getClusterMetrics().getLiveServerMetrics().size());
   }
 
   protected void startRs(ServerName server) throws IOException {
-    LOG.info("Starting regionserver {}", server.getAddress());
+    getLogger().info("Starting regionserver {}", server.getAddress());
     cluster.startRegionServer(server.getHostname(), server.getPort());
     cluster.waitForRegionServerToStart(server.getHostname(), server.getPort(), startRsTimeout);
-    LOG.info("Started regionserver {}. Reported num of rs:{}", server.getAddress(),
+    getLogger().info("Started regionserver {}. Reported num of rs:{}", server.getAddress(),
       cluster.getClusterMetrics().getLiveServerMetrics().size());
   }
 
   protected void killZKNode(ServerName server) throws IOException {
-    LOG.info("Killing zookeeper node {}", server);
+    getLogger().info("Killing zookeeper node {}", server);
     cluster.killZkNode(server);
     cluster.waitForZkNodeToStop(server, killZkNodeTimeout);
-    LOG.info("Killed zookeeper node {}. Reported num of rs:{}", server,
+    getLogger().info("Killed zookeeper node {}. Reported num of rs:{}", server,
       cluster.getClusterMetrics().getLiveServerMetrics().size());
   }
 
   protected void startZKNode(ServerName server) throws IOException {
-    LOG.info("Starting zookeeper node {}", server.getHostname());
+    getLogger().info("Starting zookeeper node {}", server.getHostname());
     cluster.startZkNode(server.getHostname(), server.getPort());
     cluster.waitForZkNodeToStart(server, startZkNodeTimeout);
-    LOG.info("Started zookeeper node {}", server);
+    getLogger().info("Started zookeeper node {}", server);
   }
 
   protected void killDataNode(ServerName server) throws IOException {
-    LOG.info("Killing datanode {}", server);
+    getLogger().info("Killing datanode {}", server);
     cluster.killDataNode(server);
     cluster.waitForDataNodeToStop(server, killDataNodeTimeout);
-    LOG.info("Killed datanode {}. Reported num of rs:{}", server,
+    getLogger().info("Killed datanode {}. Reported num of rs:{}", server,
       cluster.getClusterMetrics().getLiveServerMetrics().size());
   }
 
   protected void startDataNode(ServerName server) throws IOException {
-    LOG.info("Starting datanode {}", server.getHostname());
+    getLogger().info("Starting datanode {}", server.getHostname());
     cluster.startDataNode(server);
     cluster.waitForDataNodeToStart(server, startDataNodeTimeout);
-    LOG.info("Started datanode {}", server);
+    getLogger().info("Started datanode {}", server);
   }
 
   protected void killNameNode(ServerName server) throws IOException {
-    LOG.info("Killing namenode :-{}", server.getHostname());
+    getLogger().info("Killing namenode :-{}", server.getHostname());
     cluster.killNameNode(server);
     cluster.waitForNameNodeToStop(server, killNameNodeTimeout);
-    LOG.info("Killed namenode:{}. Reported num of rs:{}", server,
+    getLogger().info("Killed namenode:{}. Reported num of rs:{}", server,
         cluster.getClusterMetrics().getLiveServerMetrics().size());
   }
 
   protected void startNameNode(ServerName server) throws IOException {
-    LOG.info("Starting Namenode :-{}", server.getHostname());
+    getLogger().info("Starting Namenode :-{}", server.getHostname());
     cluster.startNameNode(server);
     cluster.waitForNameNodeToStart(server, startNameNodeTimeout);
-    LOG.info("Started namenode:{}", server);
+    getLogger().info("Started namenode:{}", server);
   }
   protected void unbalanceRegions(ClusterMetrics clusterStatus,
       List<ServerName> fromServers, List<ServerName> toServers,
@@ -283,7 +285,7 @@ public class Action {
       // Ugh.
       List<byte[]> regions = new LinkedList<>(serverLoad.getRegionMetrics().keySet());
       int victimRegionCount = (int)Math.ceil(fractionOfRegions * regions.size());
-      LOG.debug("Removing {} regions from {}", victimRegionCount, sn);
+      getLogger().debug("Removing {} regions from {}", victimRegionCount, sn);
       for (int i = 0; i < victimRegionCount; ++i) {
         int victimIx = RandomUtils.nextInt(0, regions.size());
         String regionId = HRegionInfo.encodeRegionName(regions.remove(victimIx));
@@ -291,8 +293,8 @@ public class Action {
       }
     }
 
-    LOG.info("Moving {} regions from {} servers to {} different servers", victimRegions.size(),
+    getLogger().info("Moving {} regions from {} servers to {} different servers",
-        fromServers.size(), toServers.size());
+      victimRegions.size(), fromServers.size(), toServers.size());
     Admin admin = this.context.getHBaseIntegrationTestingUtility().getAdmin();
     for (byte[] victimRegion : victimRegions) {
       // Don't keep moving regions if we're
@@ -311,10 +313,10 @@ public class Action {
     try {
       result = admin.balance();
     } catch (Exception e) {
-      LOG.warn("Got exception while doing balance ", e);
+      getLogger().warn("Got exception while doing balance ", e);
     }
     if (!result) {
-      LOG.error("Balancer didn't succeed");
+      getLogger().error("Balancer didn't succeed");
     }
   }
 
@@ -323,7 +325,7 @@ public class Action {
     try {
       admin.balancerSwitch(onOrOff, synchronous);
     } catch (Exception e) {
-      LOG.warn("Got exception while switching balance ", e);
+      getLogger().warn("Got exception while switching balance ", e);
     }
   }
 
@@ -338,7 +340,8 @@ public class Action {
    * @param transform the modification to perform. Callers will have the
    *                  column name as a string and a column family builder available to them
    */
-  protected void modifyAllTableColumns(TableName tableName, BiConsumer<String, ColumnFamilyDescriptorBuilder> transform) throws IOException {
+  protected void modifyAllTableColumns(TableName tableName,
+    BiConsumer<String, ColumnFamilyDescriptorBuilder> transform) throws IOException {
     HBaseTestingUtility util = this.context.getHBaseIntegrationTestingUtility();
     Admin admin = util.getAdmin();
 
@@ -369,7 +372,8 @@ public class Action {
    * @param tableName the table to modify
    * @param transform the modification to perform on each column family descriptor builder
    */
-  protected void modifyAllTableColumns(TableName tableName, Consumer<ColumnFamilyDescriptorBuilder> transform) throws IOException {
+  protected void modifyAllTableColumns(TableName tableName,
+    Consumer<ColumnFamilyDescriptorBuilder> transform) throws IOException {
     modifyAllTableColumns(tableName, (name, cfd) -> transform.accept(cfd));
   }
 

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/AddCPULoadAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
-
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
 import org.slf4j.Logger;
@@ -29,13 +28,13 @@ import org.slf4j.LoggerFactory;
  * Action that adds high cpu load to a random regionserver for a given duration
  */
 public class AddCPULoadAction extends SudoCommandAction {
-  protected static final Logger LOG = LoggerFactory.getLogger(AddCPULoadAction.class);
+  private static final Logger LOG = LoggerFactory.getLogger(AddCPULoadAction.class);
   private static final String CPU_LOAD_COMMAND =
       "seq 1 %s | xargs -I{} -n 1 -P %s timeout %s dd if=/dev/urandom of=/dev/null bs=1M " +
           "iflag=fullblock";
 
   private final long duration;
-  private long processes;
+  private final long processes;
 
   /**
    * Add high load to cpu
@@ -49,18 +48,22 @@ public class AddCPULoadAction extends SudoCommandAction {
     this.processes = processes;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   protected void localPerform() throws IOException {
-    LOG.info("Starting to execute AddCPULoadAction");
+    getLogger().info("Starting to execute AddCPULoadAction");
     ServerName server = PolicyBasedChaosMonkey.selectRandomItem(getCurrentServers());
     String hostname = server.getHostname();
 
     try {
       clusterManager.execSudo(hostname, timeout, getCommand());
     } catch (IOException ex){
-      //This will always happen. We use timeout to kill a continously running process
+      //This will always happen. We use timeout to kill a continuously running process
       //after the duration expires
     }
-    LOG.info("Finished to execute AddCPULoadAction");
+    getLogger().info("Finished to execute AddCPULoadAction");
   }
 
   private String getCommand(){

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/AddColumnAction.java

@@ -42,6 +42,10 @@ public class AddColumnAction extends Action {
     this.tableName = tableName;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void init(ActionContext context) throws IOException {
     super.init(context);
@@ -63,7 +67,7 @@ public class AddColumnAction extends Action {
       return;
     }
 
-    LOG.debug("Performing action: Adding " + columnDescriptor + " to " + tableName);
+    getLogger().debug("Performing action: Adding " + columnDescriptor + " to " + tableName);
 
     TableDescriptor modifiedTable = TableDescriptorBuilder.newBuilder(tableDescriptor)
         .setColumnFamily(columnDescriptor).build();

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/BatchRestartRsAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -21,7 +21,6 @@ package org.apache.hadoop.hbase.chaos.actions;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
-
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
 import org.slf4j.Logger;
@@ -32,17 +31,20 @@ import org.slf4j.LoggerFactory;
  */
 public class BatchRestartRsAction extends RestartActionBaseAction {
   float ratio; //ratio of regionservers to restart
-  private static final Logger LOG =
+  private static final Logger LOG = LoggerFactory.getLogger(BatchRestartRsAction.class);
-      LoggerFactory.getLogger(BatchRestartRsAction.class);
 
   public BatchRestartRsAction(long sleepTime, float ratio) {
     super(sleepTime);
     this.ratio = ratio;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info(String.format("Performing action: Batch restarting %d%% of region servers",
+    getLogger().info(String.format("Performing action: Batch restarting %d%% of region servers",
         (int)(ratio * 100)));
     List<ServerName> selectedServers = PolicyBasedChaosMonkey.selectRandomItems(getCurrentServers(),
         ratio);
@@ -55,7 +57,7 @@ public class BatchRestartRsAction extends RestartActionBaseAction {
       if (context.isStopping()) {
         break;
       }
-      LOG.info("Killing region server:" + server);
+      getLogger().info("Killing region server:" + server);
       cluster.killRegionServer(server);
       killedServers.add(server);
     }
@@ -64,13 +66,13 @@ public class BatchRestartRsAction extends RestartActionBaseAction {
       cluster.waitForRegionServerToStop(server, PolicyBasedChaosMonkey.TIMEOUT);
     }
 
-    LOG.info("Killed " + killedServers.size() + " region servers. Reported num of rs:"
+    getLogger().info("Killed " + killedServers.size() + " region servers. Reported num of rs:"
         + cluster.getClusterMetrics().getLiveServerMetrics().size());
 
     sleep(sleepTime);
 
     for (ServerName server : killedServers) {
-      LOG.info("Starting region server:" + server.getHostname());
+      getLogger().info("Starting region server:" + server.getHostname());
       cluster.startRegionServer(server.getHostname(), server.getPort());
 
     }
@@ -79,7 +81,7 @@ public class BatchRestartRsAction extends RestartActionBaseAction {
           server.getPort(),
           PolicyBasedChaosMonkey.TIMEOUT);
     }
-    LOG.info("Started " + killedServers.size() +" region servers. Reported num of rs:"
+    getLogger().info("Started " + killedServers.size() +" region servers. Reported num of rs:"
         + cluster.getClusterMetrics().getLiveServerMetrics().size());
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/ChangeBloomFilterAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.util.Random;
-
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.regionserver.BloomType;
 import org.apache.hadoop.hbase.util.BloomFilterUtil;
@@ -44,17 +43,21 @@ public class ChangeBloomFilterAction extends Action {
     this.tableName = tableName;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     final Random random = new Random();
     final BloomType[] bloomArray = BloomType.values();
     final int bloomArraySize = bloomArray.length;
 
-    LOG.info("Performing action: Change bloom filter on all columns of table " + tableName);
+    getLogger().info("Performing action: Change bloom filter on all columns of table " + tableName);
 
     modifyAllTableColumns(tableName, (columnName, columnBuilder) -> {
       BloomType bloomType = bloomArray[random.nextInt(bloomArraySize)];
-      LOG.debug("Performing action: About to set bloom filter type to "
+      getLogger().debug("Performing action: About to set bloom filter type to "
           + bloomType + " on column " + columnName + " of table " + tableName);
       columnBuilder.setBloomFilterType(bloomType);
       if (bloomType == BloomType.ROWPREFIX_FIXED_LENGTH) {
@@ -62,6 +65,6 @@ public class ChangeBloomFilterAction extends Action {
       }
     });
 
-    LOG.debug("Performing action: Just set bloom filter types on table " + tableName);
+    getLogger().debug("Performing action: Just set bloom filter types on table " + tableName);
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/ChangeCompressionAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -20,7 +20,6 @@ package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
 import java.util.Random;
-
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.io.compress.Compression.Algorithm;
 import org.apache.hadoop.io.compress.Compressor;
@@ -40,6 +39,10 @@ public class ChangeCompressionAction extends Action {
     this.random = new Random();
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws IOException {
     // Possible compression algorithms. If an algorithm is not supported,
@@ -63,13 +66,13 @@ public class ChangeCompressionAction extends Action {
         algo.returnCompressor(c);
         break;
       } catch (Throwable t) {
-        LOG.info("Performing action: Changing compression algorithms to " + algo +
+        getLogger().info("Performing action: Changing compression algorithms to " + algo +
             " is not supported, pick another one");
       }
     } while (true);
 
     final Algorithm chosenAlgo = algo; // for use in lambda
-    LOG.debug("Performing action: Changing compression algorithms on "
+    getLogger().debug("Performing action: Changing compression algorithms on "
       + tableName.getNameAsString() + " to " + chosenAlgo);
     modifyAllTableColumns(tableName, columnFamilyDescriptorBuilder -> {
       if (random.nextBoolean()) {

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/ChangeEncodingAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -20,7 +20,6 @@ package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
 import java.util.Random;
-
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.io.encoding.DataBlockEncoding;
 import org.slf4j.Logger;
@@ -39,9 +38,13 @@ public class ChangeEncodingAction extends Action {
     this.random = new Random();
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws IOException {
-    LOG.debug("Performing action: Changing encodings on " + tableName);
+    getLogger().debug("Performing action: Changing encodings on " + tableName);
     // possible DataBlockEncoding id's
     final int[] possibleIds = {0, 2, 3, 4, 6};
 
@@ -49,7 +52,7 @@ public class ChangeEncodingAction extends Action {
       short id = (short) possibleIds[random.nextInt(possibleIds.length)];
       DataBlockEncoding encoding = DataBlockEncoding.getEncodingById(id);
       columnBuilder.setDataBlockEncoding(encoding);
-      LOG.debug("Set encoding of column family " + columnName + " to: " + encoding);
+      getLogger().debug("Set encoding of column family " + columnName + " to: " + encoding);
     });
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/ChangeSplitPolicyAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -18,7 +18,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.util.Random;
-
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.Admin;
@@ -46,18 +45,21 @@ public class ChangeSplitPolicyAction extends Action {
     this.random = new Random();
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
 
   @Override
   public void perform() throws Exception {
     HBaseTestingUtility util = context.getHBaseIntegrationTestingUtility();
     Admin admin = util.getAdmin();
 
-    LOG.info("Performing action: Change split policy of table " + tableName);
+    getLogger().info("Performing action: Change split policy of table " + tableName);
     TableDescriptor tableDescriptor = admin.getDescriptor(tableName);
     TableDescriptorBuilder builder = TableDescriptorBuilder.newBuilder(tableDescriptor);
     String chosenPolicy = possiblePolicies[random.nextInt(possiblePolicies.length)];
     builder.setRegionSplitPolicyClassName(chosenPolicy);
-    LOG.info("Changing "  + tableName + " split policy to " + chosenPolicy);
+    getLogger().info("Changing "  + tableName + " split policy to " + chosenPolicy);
     admin.modifyTable(builder.build());
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/ChangeVersionsAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -20,7 +20,6 @@ package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
 import java.util.Random;
-
 import org.apache.hadoop.hbase.TableName;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -31,24 +30,28 @@ import org.slf4j.LoggerFactory;
  * Always keeps at least 1 as the number of versions.
  */
 public class ChangeVersionsAction extends Action {
-  private final TableName tableName;
   private static final Logger LOG = LoggerFactory.getLogger(ChangeVersionsAction.class);
+  private final TableName tableName;
 
-  private Random random;
+  private final Random random;
 
   public ChangeVersionsAction(TableName tableName) {
     this.tableName = tableName;
     this.random = new Random();
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws IOException {
     final int versions =  random.nextInt(3) + 1;
 
-    LOG.debug("Performing action: Changing versions on " + tableName + " to " + versions);
+    getLogger().debug("Performing action: Changing versions on " + tableName + " to " + versions);
     modifyAllTableColumns(tableName, columnBuilder -> {
       columnBuilder.setMinVersions(versions).setMaxVersions(versions);
     });
-    LOG.debug("Performing action: Just changed versions on " + tableName);
+    getLogger().debug("Performing action: Just changed versions on " + tableName);
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/CompactMobAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -46,6 +46,10 @@ public class CompactMobAction extends Action {
     this.sleepTime = sleepTime;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     HBaseTestingUtility util = context.getHBaseIntegrationTestingUtility();
@@ -57,7 +61,7 @@ public class CompactMobAction extends Action {
       return;
     }
 
-    LOG.info("Performing action: Compact mob of table " + tableName + ", major=" + major);
+    getLogger().info("Performing action: Compact mob of table " + tableName + ", major=" + major);
     try {
       if (major) {
         admin.majorCompact(tableName, CompactType.MOB);
@@ -65,7 +69,7 @@ public class CompactMobAction extends Action {
         admin.compact(tableName, CompactType.MOB);
       }
     } catch (Exception ex) {
-      LOG.warn("Mob Compaction failed, might be caused by other chaos: " + ex.getMessage());
+      getLogger().warn("Mob Compaction failed, might be caused by other chaos: " + ex.getMessage());
     }
     if (sleepTime > 0) {
       Thread.sleep(sleepTime);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/CompactRandomRegionOfTableAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.util.List;
-
 import org.apache.commons.lang3.RandomUtils;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.TableName;
@@ -33,11 +32,11 @@ import org.slf4j.LoggerFactory;
  * Region that queues a compaction of a random region from the table.
  */
 public class CompactRandomRegionOfTableAction extends Action {
+  private static final Logger LOG = LoggerFactory.getLogger(CompactRandomRegionOfTableAction.class);
+
   private final int majorRatio;
   private final long sleepTime;
   private final TableName tableName;
-  private static final Logger LOG =
-      LoggerFactory.getLogger(CompactRandomRegionOfTableAction.class);
 
   public CompactRandomRegionOfTableAction(
       TableName tableName, float majorRatio) {
@@ -51,33 +50,37 @@ public class CompactRandomRegionOfTableAction extends Action {
     this.tableName = tableName;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     HBaseTestingUtility util = context.getHBaseIntegrationTestingUtility();
     Admin admin = util.getAdmin();
     boolean major = RandomUtils.nextInt(0, 100) < majorRatio;
 
-    LOG.info("Performing action: Compact random region of table "
+    getLogger().info("Performing action: Compact random region of table "
       + tableName + ", major=" + major);
     List<RegionInfo> regions = admin.getRegions(tableName);
     if (regions == null || regions.isEmpty()) {
-      LOG.info("Table " + tableName + " doesn't have regions to compact");
+      getLogger().info("Table " + tableName + " doesn't have regions to compact");
       return;
     }
 
     RegionInfo region = PolicyBasedChaosMonkey.selectRandomItem(
-      regions.toArray(new RegionInfo[regions.size()]));
+      regions.toArray(new RegionInfo[0]));
 
     try {
       if (major) {
-        LOG.debug("Major compacting region " + region.getRegionNameAsString());
+        getLogger().debug("Major compacting region " + region.getRegionNameAsString());
         admin.majorCompactRegion(region.getRegionName());
       } else {
-        LOG.debug("Compacting region " + region.getRegionNameAsString());
+        getLogger().debug("Compacting region " + region.getRegionNameAsString());
         admin.compactRegion(region.getRegionName());
       }
     } catch (Exception ex) {
-      LOG.warn("Compaction failed, might be caused by other chaos: " + ex.getMessage());
+      getLogger().warn("Compaction failed, might be caused by other chaos: " + ex.getMessage());
     }
     if (sleepTime > 0) {
       Thread.sleep(sleepTime);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/CompactTableAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -29,10 +29,11 @@ import org.slf4j.LoggerFactory;
  * Action that queues a table compaction.
  */
 public class CompactTableAction extends Action {
+  private static final Logger LOG = LoggerFactory.getLogger(CompactTableAction.class);
+
   private final TableName tableName;
   private final int majorRatio;
   private final long sleepTime;
-  private static final Logger LOG = LoggerFactory.getLogger(CompactTableAction.class);
 
   public CompactTableAction(TableName tableName, float majorRatio) {
     this(-1, tableName, majorRatio);
@@ -45,13 +46,17 @@ public class CompactTableAction extends Action {
     this.sleepTime = sleepTime;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     HBaseTestingUtility util = context.getHBaseIntegrationTestingUtility();
     Admin admin = util.getAdmin();
     boolean major = RandomUtils.nextInt(0, 100) < majorRatio;
 
-    LOG.info("Performing action: Compact table " + tableName + ", major=" + major);
+    getLogger().info("Performing action: Compact table " + tableName + ", major=" + major);
     try {
       if (major) {
         admin.majorCompact(tableName);
@@ -59,7 +64,7 @@ public class CompactTableAction extends Action {
         admin.compact(tableName);
       }
     } catch (Exception ex) {
-      LOG.warn("Compaction failed, might be caused by other chaos: " + ex.getMessage());
+      getLogger().warn("Compaction failed, might be caused by other chaos: " + ex.getMessage());
     }
     if (sleepTime > 0) {
       Thread.sleep(sleepTime);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/CorruptDataFilesAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -34,7 +34,7 @@ import org.slf4j.LoggerFactory;
  */
 public class CorruptDataFilesAction extends Action {
   private static final Logger LOG = LoggerFactory.getLogger(CorruptDataFilesAction.class);
-  private float chance;
+  private final float chance;
 
   /**
    * Corrupts HFiles with a certain chance
@@ -44,9 +44,13 @@ public class CorruptDataFilesAction extends Action {
     this.chance = chance * 100;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info("Start corrupting data files");
+    getLogger().info("Start corrupting data files");
 
     FileSystem fs = CommonFSUtils.getRootDirFileSystem(getConf());
     Path rootDir = CommonFSUtils.getRootDir(getConf());
@@ -67,9 +71,9 @@ public class CorruptDataFilesAction extends Action {
       } finally {
         out.close();
       }
-      LOG.info("Corrupting {}", status.getPath());
+      getLogger().info("Corrupting {}", status.getPath());
     }
-    LOG.info("Done corrupting data files");
+    getLogger().info("Done corrupting data files");
   }
 
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/CorruptPacketsCommandAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
-
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
 import org.slf4j.Logger;
@@ -31,8 +30,8 @@ import org.slf4j.LoggerFactory;
  */
 public class CorruptPacketsCommandAction extends TCCommandAction {
   private static final Logger LOG = LoggerFactory.getLogger(CorruptPacketsCommandAction.class);
-  private float ratio;
+  private final float ratio;
-  private long duration;
+  private final long duration;
 
   /**
    * Corrupt network packets on a random regionserver.
@@ -48,8 +47,12 @@ public class CorruptPacketsCommandAction extends TCCommandAction {
     this.duration = duration;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   protected void localPerform() throws IOException {
-    LOG.info("Starting to execute CorruptPacketsCommandAction");
+    getLogger().info("Starting to execute CorruptPacketsCommandAction");
     ServerName server = PolicyBasedChaosMonkey.selectRandomItem(getCurrentServers());
     String hostname = server.getHostname();
 
@@ -57,12 +60,12 @@ public class CorruptPacketsCommandAction extends TCCommandAction {
       clusterManager.execSudoWithRetries(hostname, timeout, getCommand(ADD));
       Thread.sleep(duration);
     } catch (InterruptedException e) {
-      LOG.debug("Failed to run the command for the full duration", e);
+      getLogger().debug("Failed to run the command for the full duration", e);
     } finally {
       clusterManager.execSudoWithRetries(hostname, timeout, getCommand(DELETE));
     }
 
-    LOG.info("Finished to execute CorruptPacketsCommandAction");
+    getLogger().info("Finished to execute CorruptPacketsCommandAction");
   }
 
   private String getCommand(String operation){

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/DecreaseMaxHFileSizeAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -20,16 +20,18 @@ package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
 import java.util.Random;
-
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.TableDescriptor;
 import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class DecreaseMaxHFileSizeAction extends Action {
+  private static final Logger LOG = LoggerFactory.getLogger(DecreaseMaxHFileSizeAction.class);
 
-  private static final long minFileSize = 1 *  1024 * 1024 * 1024L;
+  private static final long minFileSize = 1024 * 1024 * 1024L;
 
   private final long sleepTime;
   private final TableName tableName;
@@ -42,6 +44,10 @@ public class DecreaseMaxHFileSizeAction extends Action {
     this.random = new Random();
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void init(ActionContext context) throws IOException {
     super.init(context);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/DelayPacketsCommandAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
-
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
 import org.slf4j.Logger;
@@ -30,8 +29,8 @@ import org.slf4j.LoggerFactory;
  */
 public class DelayPacketsCommandAction extends TCCommandAction {
   private static final Logger LOG = LoggerFactory.getLogger(DelayPacketsCommandAction.class);
-  private long delay;
+  private final long delay;
-  private long duration;
+  private final long duration;
 
   /**
    * Adds latency to communication on a random region server
@@ -47,8 +46,12 @@ public class DelayPacketsCommandAction extends TCCommandAction {
     this.duration = duration;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   protected void localPerform() throws IOException {
-    LOG.info("Starting to execute DelayPacketsCommandAction");
+    getLogger().info("Starting to execute DelayPacketsCommandAction");
     ServerName server = PolicyBasedChaosMonkey.selectRandomItem(getCurrentServers());
     String hostname = server.getHostname();
 
@@ -56,12 +59,12 @@ public class DelayPacketsCommandAction extends TCCommandAction {
       clusterManager.execSudoWithRetries(hostname, timeout, getCommand(ADD));
       Thread.sleep(duration);
     } catch (InterruptedException e) {
-      LOG.debug("Failed to run the command for the full duration", e);
+      getLogger().debug("Failed to run the command for the full duration", e);
     } finally {
       clusterManager.execSudoWithRetries(hostname, timeout, getCommand(DELETE));
     }
 
-    LOG.info("Finished to execute DelayPacketsCommandAction");
+    getLogger().info("Finished to execute DelayPacketsCommandAction");
   }
 
   private String getCommand(String operation){

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/DeleteDataFilesAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -33,7 +33,7 @@ import org.slf4j.LoggerFactory;
  */
 public class DeleteDataFilesAction extends Action {
   private static final Logger LOG = LoggerFactory.getLogger(DeleteDataFilesAction.class);
-  private float chance;
+  private final float chance;
 
   /**
    * Delets HFiles with a certain chance
@@ -43,9 +43,13 @@ public class DeleteDataFilesAction extends Action {
     this.chance = chance * 100;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info("Start deleting data files");
+    getLogger().info("Start deleting data files");
     FileSystem fs = CommonFSUtils.getRootDirFileSystem(getConf());
     Path rootDir = CommonFSUtils.getRootDir(getConf());
     Path defaultDir = rootDir.suffix("/data/default");
@@ -58,9 +62,9 @@ public class DeleteDataFilesAction extends Action {
       if(RandomUtils.nextFloat(0, 100) > chance){
         continue;
       }
-      fs.delete(status.getPath());
+      fs.delete(status.getPath(), true);
-      LOG.info("Deleting {}", status.getPath());
+      getLogger().info("Deleting {}", status.getPath());
     }
-    LOG.info("Done deleting data files");
+    getLogger().info("Done deleting data files");
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/DumpClusterStatusAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
-
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -27,8 +26,11 @@ import org.slf4j.LoggerFactory;
  * Action to dump the cluster status.
  */
 public class DumpClusterStatusAction extends Action {
-  private static final Logger LOG =
+  private static final Logger LOG = LoggerFactory.getLogger(DumpClusterStatusAction.class);
-      LoggerFactory.getLogger(DumpClusterStatusAction.class);
+
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
 
   @Override
   public void init(ActionContext context) throws IOException {
@@ -37,7 +39,7 @@ public class DumpClusterStatusAction extends Action {
 
   @Override
   public void perform() throws Exception {
-    LOG.debug("Performing action: Dump cluster status");
+    getLogger().debug("Performing action: Dump cluster status");
-    LOG.info("Cluster status\n" + cluster.getClusterMetrics());
+    getLogger().info("Cluster status\n" + cluster.getClusterMetrics());
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/DuplicatePacketsCommandAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
-
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
 import org.slf4j.Logger;
@@ -31,8 +30,8 @@ import org.slf4j.LoggerFactory;
  */
 public class DuplicatePacketsCommandAction extends TCCommandAction {
   private static final Logger LOG = LoggerFactory.getLogger(DuplicatePacketsCommandAction.class);
-  private float ratio;
+  private final float ratio;
-  private long duration;
+  private final long duration;
 
   /**
    * Duplicate network packets on a random regionserver.
@@ -48,8 +47,12 @@ public class DuplicatePacketsCommandAction extends TCCommandAction {
     this.duration = duration;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   protected void localPerform() throws IOException {
-    LOG.info("Starting to execute DuplicatePacketsCommandAction");
+    getLogger().info("Starting to execute DuplicatePacketsCommandAction");
     ServerName server = PolicyBasedChaosMonkey.selectRandomItem(getCurrentServers());
     String hostname = server.getHostname();
 
@@ -57,12 +60,12 @@ public class DuplicatePacketsCommandAction extends TCCommandAction {
       clusterManager.execSudoWithRetries(hostname, timeout, getCommand(ADD));
       Thread.sleep(duration);
     } catch (InterruptedException e) {
-      LOG.debug("Failed to run the command for the full duration", e);
+      getLogger().debug("Failed to run the command for the full duration", e);
     } finally {
       clusterManager.execSudoWithRetries(hostname, timeout, getCommand(DELETE));
     }
 
-    LOG.info("Finished to execute DuplicatePacketsCommandAction");
+    getLogger().info("Finished to execute DuplicatePacketsCommandAction");
   }
 
   private String getCommand(String operation){

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/FillDiskCommandAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
-
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
 import org.slf4j.Logger;
@@ -31,9 +30,9 @@ import org.slf4j.LoggerFactory;
  */
 public class FillDiskCommandAction extends SudoCommandAction {
   private static final Logger LOG = LoggerFactory.getLogger(FillDiskCommandAction.class);
-  private long size;
+  private final long size;
-  private long duration;
+  private final long duration;
-  private String path;
+  private final String path;
 
   /**
    * Fill the disk on a random regionserver.
@@ -52,20 +51,24 @@ public class FillDiskCommandAction extends SudoCommandAction {
     this.path = path;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   protected void localPerform() throws IOException {
-    LOG.info("Starting to execute FillDiskCommandAction");
+    getLogger().info("Starting to execute FillDiskCommandAction");
     ServerName server = PolicyBasedChaosMonkey.selectRandomItem(getCurrentServers());
     String hostname = server.getHostname();
 
     try {
       clusterManager.execSudo(hostname, duration, getFillCommand());
     } catch (IOException ex) {
-      LOG.info("Potential timeout. We try to stop the dd process on target machine");
+      getLogger().info("Potential timeout. We try to stop the dd process on target machine");
       clusterManager.execSudoWithRetries(hostname, timeout, getStopCommand());
       throw ex;
     } finally {
       clusterManager.execSudoWithRetries(hostname, timeout, getClearCommand());
-      LOG.info("Finished to execute FillDiskCommandAction");
+      getLogger().info("Finished to execute FillDiskCommandAction");
     }
   }
 
@@ -82,6 +85,6 @@ public class FillDiskCommandAction extends SudoCommandAction {
   }
 
   private String getStopCommand() {
-    return String.format("killall dd");
+    return "killall dd";
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/FlushRandomRegionOfTableAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -45,25 +45,29 @@ public class FlushRandomRegionOfTableAction extends Action {
     this.tableName = tableName;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     HBaseTestingUtility util = context.getHBaseIntegrationTestingUtility();
     Admin admin = util.getAdmin();
 
-    LOG.info("Performing action: Flush random region of table " + tableName);
+    getLogger().info("Performing action: Flush random region of table " + tableName);
     List<RegionInfo> regions = admin.getRegions(tableName);
     if (regions == null || regions.isEmpty()) {
-      LOG.info("Table " + tableName + " doesn't have regions to flush");
+      getLogger().info("Table " + tableName + " doesn't have regions to flush");
       return;
     }
 
     RegionInfo region = PolicyBasedChaosMonkey.selectRandomItem(
-      regions.toArray(new RegionInfo[regions.size()]));
+      regions.toArray(new RegionInfo[0]));
-    LOG.debug("Flushing region " + region.getRegionNameAsString());
+    getLogger().debug("Flushing region " + region.getRegionNameAsString());
     try {
       admin.flushRegion(region.getRegionName());
     } catch (Exception ex) {
-      LOG.warn("Flush failed, might be caused by other chaos: " + ex.getMessage());
+      getLogger().warn("Flush failed, might be caused by other chaos: " + ex.getMessage());
     }
     if (sleepTime > 0) {
       Thread.sleep(sleepTime);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/FlushTableAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -28,8 +28,7 @@ import org.slf4j.LoggerFactory;
 * Action that tries to flush a table.
 */
 public class FlushTableAction extends Action {
-  private static final Logger LOG =
+  private static final Logger LOG = LoggerFactory.getLogger(FlushTableAction.class);
-      LoggerFactory.getLogger(FlushTableAction.class);
   private final long sleepTime;
   private final TableName tableName;
 
@@ -42,6 +41,10 @@ public class FlushTableAction extends Action {
     this.tableName = tableName;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     HBaseTestingUtility util = context.getHBaseIntegrationTestingUtility();
@@ -52,11 +55,11 @@ public class FlushTableAction extends Action {
       return;
     }
 
-    LOG.info("Performing action: Flush table " + tableName);
+    getLogger().info("Performing action: Flush table " + tableName);
     try {
       admin.flush(tableName);
     } catch (Exception ex) {
-      LOG.warn("Flush failed, might be caused by other chaos: " + ex.getMessage());
+      getLogger().warn("Flush failed, might be caused by other chaos: " + ex.getMessage());
     }
     if (sleepTime > 0) {
       Thread.sleep(sleepTime);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/ForceBalancerAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -25,8 +25,11 @@ import org.slf4j.LoggerFactory;
 * Action that tries to force a balancer run.
 */
 public class ForceBalancerAction extends Action {
-  private static final Logger LOG =
+  private static final Logger LOG = LoggerFactory.getLogger(ForceBalancerAction.class);
-      LoggerFactory.getLogger(ForceBalancerAction.class);
+
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
 
   @Override
   public void perform() throws Exception {
@@ -34,7 +37,7 @@ public class ForceBalancerAction extends Action {
     if (context.isStopping()) {
       return;
     }
-    LOG.info("Balancing regions");
+    getLogger().info("Balancing regions");
     forceBalancer();
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/GracefulRollingRestartRsAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -39,35 +39,38 @@ public class GracefulRollingRestartRsAction extends RestartActionBaseAction {
     super(sleepTime);
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info("Performing action: Rolling restarting non-master region servers");
+    getLogger().info("Performing action: Rolling restarting non-master region servers");
     List<ServerName> selectedServers = selectServers();
 
-    LOG.info("Disabling balancer to make unloading possible");
+    getLogger().info("Disabling balancer to make unloading possible");
     setBalancer(false, true);
 
     for (ServerName server : selectedServers) {
       String rsName = server.getAddress().toString();
       try (RegionMover rm =
           new RegionMover.RegionMoverBuilder(rsName, getConf()).ack(true).build()) {
-        LOG.info("Unloading {}", server);
+        getLogger().info("Unloading {}", server);
         rm.unload();
-        LOG.info("Restarting {}", server);
+        getLogger().info("Restarting {}", server);
         gracefulRestartRs(server, sleepTime);
-        LOG.info("Loading {}", server);
+        getLogger().info("Loading {}", server);
         rm.load();
       } catch (Shell.ExitCodeException e) {
-        LOG.info("Problem restarting but presume successful; code={}", e.getExitCode(), e);
+        getLogger().info("Problem restarting but presume successful; code={}", e.getExitCode(), e);
       }
       sleep(RandomUtils.nextInt(0, (int)sleepTime));
     }
-    LOG.info("Enabling balancer");
+    getLogger().info("Enabling balancer");
     setBalancer(true, true);
   }
 
   protected List<ServerName> selectServers() throws IOException {
     return Arrays.asList(getCurrentServers());
   }
-
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/LosePacketsCommandAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
-
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
 import org.slf4j.Logger;
@@ -31,8 +30,8 @@ import org.slf4j.LoggerFactory;
  */
 public class LosePacketsCommandAction extends TCCommandAction {
   private static final Logger LOG = LoggerFactory.getLogger(LosePacketsCommandAction.class);
-  private float ratio;
+  private final float ratio;
-  private long duration;
+  private final long duration;
 
   /**
    * Lose network packets on a random regionserver.
@@ -48,8 +47,12 @@ public class LosePacketsCommandAction extends TCCommandAction {
     this.duration = duration;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   protected void localPerform() throws IOException {
-    LOG.info("Starting to execute LosePacketsCommandAction");
+    getLogger().info("Starting to execute LosePacketsCommandAction");
     ServerName server = PolicyBasedChaosMonkey.selectRandomItem(getCurrentServers());
     String hostname = server.getHostname();
 
@@ -57,12 +60,12 @@ public class LosePacketsCommandAction extends TCCommandAction {
       clusterManager.execSudoWithRetries(hostname, timeout, getCommand(ADD));
       Thread.sleep(duration);
     } catch (InterruptedException e) {
-      LOG.debug("Failed to run the command for the full duration", e);
+      getLogger().debug("Failed to run the command for the full duration", e);
     } finally {
       clusterManager.execSudoWithRetries(hostname, timeout, getCommand(DELETE));
     }
 
-    LOG.info("Finished to execute LosePacketsCommandAction");
+    getLogger().info("Finished to execute LosePacketsCommandAction");
   }
 
   private String getCommand(String operation){

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/MergeRandomAdjacentRegionsOfTableAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -45,22 +45,26 @@ public class MergeRandomAdjacentRegionsOfTableAction extends Action {
     this.sleepTime = sleepTime;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     HBaseTestingUtility util = context.getHBaseIntegrationTestingUtility();
     Admin admin = util.getAdmin();
 
-    LOG.info("Performing action: Merge random adjacent regions of table " + tableName);
+    getLogger().info("Performing action: Merge random adjacent regions of table " + tableName);
     List<RegionInfo> regions = admin.getRegions(tableName);
     if (regions == null || regions.size() < 2) {
-      LOG.info("Table " + tableName + " doesn't have enough regions to merge");
+      getLogger().info("Table " + tableName + " doesn't have enough regions to merge");
       return;
     }
 
     int i = RandomUtils.nextInt(0, regions.size() - 1);
     RegionInfo a = regions.get(i++);
     RegionInfo b = regions.get(i);
-    LOG.debug("Merging " + a.getRegionNameAsString() + " and " + b.getRegionNameAsString());
+    getLogger().debug("Merging " + a.getRegionNameAsString() + " and " + b.getRegionNameAsString());
 
     // Don't try the merge if we're stopping
     if (context.isStopping()) {
@@ -70,7 +74,7 @@ public class MergeRandomAdjacentRegionsOfTableAction extends Action {
     try {
       admin.mergeRegionsAsync(a.getEncodedNameAsBytes(), b.getEncodedNameAsBytes(), false);
     } catch (Exception ex) {
-      LOG.warn("Merge failed, might be caused by other chaos: " + ex.getMessage());
+      getLogger().warn("Merge failed, might be caused by other chaos: " + ex.getMessage());
     }
     if (sleepTime > 0) {
       Thread.sleep(sleepTime);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/MoveRandomRegionOfTableAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.util.List;
-
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
@@ -32,8 +31,7 @@ import org.slf4j.LoggerFactory;
 * Action that tries to move a random region of a table.
 */
 public class MoveRandomRegionOfTableAction extends Action {
-  private static final Logger LOG =
+  private static final Logger LOG = LoggerFactory.getLogger(MoveRandomRegionOfTableAction.class);
-      LoggerFactory.getLogger(MoveRandomRegionOfTableAction.class);
   private final long sleepTime;
   private final TableName tableName;
 
@@ -46,6 +44,10 @@ public class MoveRandomRegionOfTableAction extends Action {
     this.tableName = tableName;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     if (sleepTime > 0) {
@@ -55,18 +57,19 @@ public class MoveRandomRegionOfTableAction extends Action {
     HBaseTestingUtility util = context.getHBaseIntegrationTestingUtility();
     Admin admin = util.getAdmin();
 
-    LOG.info("Performing action: Move random region of table " + tableName);
+    getLogger().info("Performing action: Move random region of table " + tableName);
     List<RegionInfo> regions = admin.getRegions(tableName);
     if (regions == null || regions.isEmpty()) {
-      LOG.info("Table " + tableName + " doesn't have regions to move");
+      getLogger().info("Table " + tableName + " doesn't have regions to move");
       return;
     }
 
     RegionInfo region = PolicyBasedChaosMonkey.selectRandomItem(
-      regions.toArray(new RegionInfo[regions.size()]));
+      regions.toArray(new RegionInfo[0]));
-    LOG.debug("Move random region {}", region.getRegionNameAsString());
+    getLogger().debug("Move random region {}", region.getRegionNameAsString());
     // Use facility over in MoveRegionsOfTableAction...
-    MoveRegionsOfTableAction.moveRegion(admin, MoveRegionsOfTableAction.getServers(admin), region);
+    MoveRegionsOfTableAction.moveRegion(admin, MoveRegionsOfTableAction.getServers(admin),
+      region, getLogger());
     if (sleepTime > 0) {
       Thread.sleep(sleepTime);
     }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/MoveRegionsOfTableAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -22,11 +22,9 @@ import java.io.IOException;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
-
 import org.apache.commons.lang3.RandomUtils;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
-import org.apache.hadoop.hbase.chaos.factories.MonkeyConstants;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.slf4j.Logger;
@@ -36,22 +34,21 @@ import org.slf4j.LoggerFactory;
 * Action that tries to move every region of a table.
 */
 public class MoveRegionsOfTableAction extends Action {
-  private static final Logger LOG =
+  private static final Logger LOG = LoggerFactory.getLogger(MoveRegionsOfTableAction.class);
-      LoggerFactory.getLogger(MoveRegionsOfTableAction.class);
   private final long sleepTime;
   private final TableName tableName;
   private final long maxTime;
 
-  public MoveRegionsOfTableAction(TableName tableName) {
-    this(-1, MonkeyConstants.DEFAULT_MOVE_REGIONS_MAX_TIME, tableName);
-  }
-
   public MoveRegionsOfTableAction(long sleepTime, long maxSleepTime, TableName tableName) {
     this.sleepTime = sleepTime;
     this.tableName = tableName;
     this.maxTime = maxSleepTime;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     if (sleepTime > 0) {
@@ -61,10 +58,10 @@ public class MoveRegionsOfTableAction extends Action {
     Admin admin = this.context.getHBaseIntegrationTestingUtility().getAdmin();
     ServerName[] servers = getServers(admin);
 
-    LOG.info("Performing action: Move regions of table {}", tableName);
+    getLogger().info("Performing action: Move regions of table {}", tableName);
     List<RegionInfo> regions = admin.getRegions(tableName);
     if (regions == null || regions.isEmpty()) {
-      LOG.info("Table {} doesn't have regions to move", tableName);
+      getLogger().info("Table {} doesn't have regions to move", tableName);
       return;
     }
 
@@ -77,7 +74,7 @@ public class MoveRegionsOfTableAction extends Action {
         return;
       }
 
-      moveRegion(admin, servers, regionInfo);
+      moveRegion(admin, servers, regionInfo, getLogger());
       if (sleepTime > 0) {
         Thread.sleep(sleepTime);
       }
@@ -92,16 +89,16 @@ public class MoveRegionsOfTableAction extends Action {
 
   static ServerName [] getServers(Admin admin) throws IOException {
     Collection<ServerName> serversList = admin.getRegionServers();
-    return serversList.toArray(new ServerName[serversList.size()]);
+    return serversList.toArray(new ServerName[0]);
   }
 
-  static void moveRegion(Admin admin, ServerName [] servers, RegionInfo regionInfo) {
+  static void moveRegion(Admin admin, ServerName [] servers, RegionInfo regionInfo, Logger logger) {
     try {
       ServerName destServerName = servers[RandomUtils.nextInt(0, servers.length)];
-      LOG.debug("Moving {} to {}", regionInfo.getRegionNameAsString(), destServerName);
+      logger.debug("Moving {} to {}", regionInfo.getRegionNameAsString(), destServerName);
       admin.move(regionInfo.getEncodedNameAsBytes(), destServerName);
     } catch (Exception ex) {
-      LOG.warn("Move failed, might be caused by other chaos: {}", ex.getMessage());
+      logger.warn("Move failed, might be caused by other chaos: {}", ex.getMessage());
     }
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/RemoveColumnAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -21,7 +21,6 @@ package org.apache.hadoop.hbase.chaos.actions;
 import java.io.IOException;
 import java.util.Random;
 import java.util.Set;
-
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
@@ -40,7 +39,7 @@ public class RemoveColumnAction extends Action {
   private final TableName tableName;
   private final Set<String> protectedColumns;
   private Admin admin;
-  private Random random;
+  private final Random random;
 
   public RemoveColumnAction(TableName tableName, Set<String> protectedColumns) {
     this.tableName = tableName;
@@ -48,6 +47,10 @@ public class RemoveColumnAction extends Action {
     random = new Random();
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void init(ActionContext context) throws IOException {
     super.init(context);
@@ -69,7 +72,7 @@ public class RemoveColumnAction extends Action {
       index = random.nextInt(columnDescriptors.length);
     }
     byte[] colDescName = columnDescriptors[index].getName();
-    LOG.debug("Performing action: Removing " + Bytes.toString(colDescName)+ " from "
+    getLogger().debug("Performing action: Removing " + Bytes.toString(colDescName)+ " from "
         + tableName.getNameAsString());
 
     TableDescriptorBuilder builder = TableDescriptorBuilder.newBuilder(tableDescriptor);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/ReorderPacketsCommandAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
-
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
 import org.slf4j.Logger;
@@ -31,9 +30,9 @@ import org.slf4j.LoggerFactory;
  */
 public class ReorderPacketsCommandAction extends TCCommandAction {
   private static final Logger LOG = LoggerFactory.getLogger(ReorderPacketsCommandAction.class);
-  private float ratio;
+  private final float ratio;
-  private long duration;
+  private final long duration;
-  private long delay;
+  private final long delay;
 
   /**
    * Reorder network packets on a random regionserver.
@@ -52,8 +51,12 @@ public class ReorderPacketsCommandAction extends TCCommandAction {
     this.delay = delay;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   protected void localPerform() throws IOException {
-    LOG.info("Starting to execute ReorderPacketsCommandAction");
+    getLogger().info("Starting to execute ReorderPacketsCommandAction");
     ServerName server = PolicyBasedChaosMonkey.selectRandomItem(getCurrentServers());
     String hostname = server.getHostname();
 
@@ -61,12 +64,12 @@ public class ReorderPacketsCommandAction extends TCCommandAction {
       clusterManager.execSudoWithRetries(hostname, timeout, getCommand(ADD));
       Thread.sleep(duration);
     } catch (InterruptedException e) {
-      LOG.debug("Failed to run the command for the full duration", e);
+      getLogger().debug("Failed to run the command for the full duration", e);
     } finally {
       clusterManager.execSudoWithRetries(hostname, timeout, getCommand(DELETE));
     }
 
-    LOG.info("Finished to execute ReorderPacketsCommandAction");
+    getLogger().info("Finished to execute ReorderPacketsCommandAction");
   }
 
   private String getCommand(String operation){

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/RestartActionBaseAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,18 +19,13 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
-
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.util.Threads;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /**
 * Base class for restarting HBaseServer's
 */
-public class RestartActionBaseAction extends Action {
+public abstract class RestartActionBaseAction extends Action {
-  private static final Logger LOG =
-      LoggerFactory.getLogger(RestartActionBaseAction.class);
   long sleepTime; // how long should we sleep
 
   public RestartActionBaseAction(long sleepTime) {
@@ -38,7 +33,7 @@ public class RestartActionBaseAction extends Action {
   }
 
   void sleep(long sleepTime) {
-    LOG.info("Sleeping for:" + sleepTime);
+    getLogger().info("Sleeping for:" + sleepTime);
     Threads.sleep(sleepTime);
   }
 
@@ -49,10 +44,10 @@ public class RestartActionBaseAction extends Action {
       return;
     }
 
-    LOG.info("Killing master: {}", server);
+    getLogger().info("Killing master: {}", server);
     killMaster(server);
     sleep(sleepTime);
-    LOG.info("Starting master: {}", server);
+    getLogger().info("Starting master: {}", server);
     startMaster(server);
   }
 
@@ -68,10 +63,10 @@ public class RestartActionBaseAction extends Action {
     if (context.isStopping()) {
       return;
     }
-    LOG.info("Stopping region server: {}", server);
+    getLogger().info("Stopping region server: {}", server);
     stopRs(server);
     sleep(sleepTime);
-    LOG.info("Starting region server: {}", server);
+    getLogger().info("Starting region server: {}", server);
     startRs(server);
   }
 
@@ -81,10 +76,10 @@ public class RestartActionBaseAction extends Action {
     if (context.isStopping()) {
       return;
     }
-    LOG.info("Killing region server: {}", server);
+    getLogger().info("Killing region server: {}", server);
     killRs(server);
     sleep(sleepTime);
-    LOG.info("Starting region server: {}", server);
+    getLogger().info("Starting region server: {}", server);
     startRs(server);
   }
 
@@ -94,10 +89,10 @@ public class RestartActionBaseAction extends Action {
     if (context.isStopping()) {
       return;
     }
-    LOG.info("Killing zookeeper node: {}", server);
+    getLogger().info("Killing zookeeper node: {}", server);
     killZKNode(server);
     sleep(sleepTime);
-    LOG.info("Starting zookeeper node: {}", server);
+    getLogger().info("Starting zookeeper node: {}", server);
     startZKNode(server);
   }
 
@@ -107,10 +102,10 @@ public class RestartActionBaseAction extends Action {
     if (context.isStopping()) {
       return;
     }
-    LOG.info("Killing data node: {}", server);
+    getLogger().info("Killing data node: {}", server);
     killDataNode(server);
     sleep(sleepTime);
-    LOG.info("Starting data node: {}", server);
+    getLogger().info("Starting data node: {}", server);
     startDataNode(server);
   }
 
@@ -120,11 +115,10 @@ public class RestartActionBaseAction extends Action {
     if (context.isStopping()) {
       return;
     }
-    LOG.info("Killing name node: {}", server);
+    getLogger().info("Killing name node: {}", server);
     killNameNode(server);
     sleep(sleepTime);
-    LOG.info("Starting name node: {}", server);
+    getLogger().info("Starting name node: {}", server);
     startNameNode(server);
   }
-
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/RestartActiveMasterAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -31,9 +31,14 @@ public class RestartActiveMasterAction extends RestartActionBaseAction {
   public RestartActiveMasterAction(long sleepTime) {
     super(sleepTime);
   }
+
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info("Performing action: Restart active master");
+    getLogger().info("Performing action: Restart active master");
 
     ServerName master = cluster.getClusterMetrics().getMasterName();
     restartMaster(master, sleepTime);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/RestartActiveNameNodeAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -51,9 +51,13 @@ public class RestartActiveNameNodeAction extends RestartActionBaseAction {
     super(sleepTime);
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info("Performing action: Restart active namenode");
+    getLogger().info("Performing action: Restart active namenode");
     Configuration conf = CommonFSUtils.getRootDir(getConf()).getFileSystem(getConf()).getConf();
     String nameServiceID = DFSUtil.getNamenodeNameServiceId(conf);
     if (!HAUtil.isHAEnabled(conf, nameServiceID)) {
@@ -85,9 +89,9 @@ public class RestartActiveNameNodeAction extends RestartActionBaseAction {
     if (activeNamenode == null) {
       throw new Exception("No active Name node found in zookeeper under " + hadoopHAZkNode);
     }
-    LOG.info("Found active namenode host:" + activeNamenode);
+    getLogger().info("Found active namenode host:" + activeNamenode);
     ServerName activeNNHost = ServerName.valueOf(activeNamenode, -1, -1);
-    LOG.info("Restarting Active NameNode :" + activeNamenode);
+    getLogger().info("Restarting Active NameNode :" + activeNamenode);
     restartNameNode(activeNNHost, sleepTime);
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/RestartRandomDataNodeAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -41,9 +41,13 @@ public class RestartRandomDataNodeAction extends RestartActionBaseAction {
     super(sleepTime);
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info("Performing action: Restart random data node");
+    getLogger().info("Performing action: Restart random data node");
     ServerName server = PolicyBasedChaosMonkey.selectRandomItem(getDataNodes());
     restartDataNode(server, sleepTime);
   }
@@ -56,6 +60,6 @@ public class RestartRandomDataNodeAction extends RestartActionBaseAction {
     for (DatanodeInfo dataNode: dfsClient.datanodeReport(HdfsConstants.DatanodeReportType.LIVE)) {
       hosts.add(ServerName.valueOf(dataNode.getHostName(), -1, -1));
     }
-    return hosts.toArray(new ServerName[hosts.size()]);
+    return hosts.toArray(new ServerName[0]);
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/RestartRandomRsAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -33,9 +33,13 @@ public class RestartRandomRsAction extends RestartActionBaseAction {
     super(sleepTime);
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info("Performing action: Restart random region server");
+    getLogger().info("Performing action: Restart random region server");
     ServerName server = PolicyBasedChaosMonkey.selectRandomItem(getCurrentServers());
 
     restartRs(server, sleepTime);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/RestartRandomRsExceptMetaAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -20,12 +20,20 @@ package org.apache.hadoop.hbase.chaos.actions;
 
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class RestartRandomRsExceptMetaAction extends RestartRandomRsAction {
+  private static final Logger LOG = LoggerFactory.getLogger(RestartRandomRsExceptMetaAction.class);
+
   public RestartRandomRsExceptMetaAction(long sleepTime) {
     super(sleepTime);
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     int tries = 10;

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/RestartRandomZKNodeAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -34,9 +34,13 @@ public class RestartRandomZKNodeAction extends RestartActionBaseAction {
     super(sleepTime);
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info("Performing action: Restart random zookeeper node");
+    getLogger().info("Performing action: Restart random zookeeper node");
     ServerName server = PolicyBasedChaosMonkey.selectRandomItem(
         ZKServerTool.readZKNodes(getConf()));
     restartZKNode(server, sleepTime);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/RestartRsHoldingMetaAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -33,12 +33,17 @@ public class RestartRsHoldingMetaAction extends RestartActionBaseAction {
   public RestartRsHoldingMetaAction(long sleepTime) {
     super(sleepTime);
   }
+
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info("Performing action: Restart region server holding META");
+    getLogger().info("Performing action: Restart region server holding META");
     ServerName server = cluster.getServerHoldingMeta();
     if (server == null) {
-      LOG.warn("No server is holding hbase:meta right now.");
+      getLogger().warn("No server is holding hbase:meta right now.");
       return;
     }
     ClusterMetrics clusterStatus = cluster.getClusterMetrics();

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/RestartRsHoldingTableAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.util.List;
-
 import org.apache.commons.lang3.RandomUtils;
 import org.apache.hadoop.hbase.HRegionLocation;
 import org.apache.hadoop.hbase.client.RegionLocator;
@@ -30,8 +29,7 @@ import org.slf4j.LoggerFactory;
 * Action that restarts an HRegionServer holding one of the regions of the table.
 */
 public class RestartRsHoldingTableAction extends RestartActionBaseAction {
-  private static final Logger LOG =
+  private static final Logger LOG = LoggerFactory.getLogger(RestartRsHoldingTableAction.class);
-      LoggerFactory.getLogger(RestartRsHoldingTableAction.class);
 
   private final RegionLocator locator;
 
@@ -40,9 +38,14 @@ public class RestartRsHoldingTableAction extends RestartActionBaseAction {
     this.locator = locator;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info("Performing action: Restart random RS holding table " + this.locator.getName());
+    getLogger().info(
+      "Performing action: Restart random RS holding table " + this.locator.getName());
 
     List<HRegionLocation> locations = locator.getAllRegionLocations();
     restartRs(locations.get(RandomUtils.nextInt(0, locations.size())).getServerName(), sleepTime);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/RollingBatchRestartRsAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -23,7 +23,6 @@ import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Queue;
-
 import org.apache.commons.lang3.RandomUtils;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
@@ -60,10 +59,14 @@ public class RollingBatchRestartRsAction extends BatchRestartRsAction {
     START
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info(String.format("Performing action: Rolling batch restarting %d%% of region servers",
+    getLogger().info("Performing action: Rolling batch restarting {}% of region servers",
-        (int)(ratio * 100)));
+        (int)(ratio * 100));
     List<ServerName> selectedServers = selectServers();
 
     Queue<ServerName> serversToBeKilled = new LinkedList<>(selectedServers);
@@ -71,8 +74,8 @@ public class RollingBatchRestartRsAction extends BatchRestartRsAction {
 
     // loop while there are servers to be killed or dead servers to be restarted
     while ((!serversToBeKilled.isEmpty() || !deadServers.isEmpty())  && !context.isStopping()) {
-      KillOrStart action = KillOrStart.KILL;
 
+      final KillOrStart action;
       if (serversToBeKilled.isEmpty()) { // no more servers to kill
         action = KillOrStart.START;
       } else if (deadServers.isEmpty()) {
@@ -95,7 +98,7 @@ public class RollingBatchRestartRsAction extends BatchRestartRsAction {
           } catch (org.apache.hadoop.util.Shell.ExitCodeException e) {
             // We've seen this in test runs where we timeout but the kill went through. HBASE-9743
             // So, add to deadServers even if exception so the start gets called.
-            LOG.info("Problem killing but presume successful; code=" + e.getExitCode(), e);
+            getLogger().info("Problem killing but presume successful; code={}", e.getExitCode(), e);
           }
           deadServers.add(server);
           break;
@@ -106,7 +109,7 @@ public class RollingBatchRestartRsAction extends BatchRestartRsAction {
           } catch (org.apache.hadoop.util.Shell.ExitCodeException e) {
             // The start may fail but better to just keep going though we may lose server.
             //
-            LOG.info("Problem starting, will retry; code=" + e.getExitCode(), e);
+            getLogger().info("Problem starting, will retry; code={}", e.getExitCode(), e);
           }
           break;
       }
@@ -121,25 +124,23 @@ public class RollingBatchRestartRsAction extends BatchRestartRsAction {
 
   /**
    * Small test to ensure the class basically works.
-   * @param args
-   * @throws Exception
    */
   public static void main(final String[] args) throws Exception {
     RollingBatchRestartRsAction action = new RollingBatchRestartRsAction(1, 1.0f) {
       private int invocations = 0;
       @Override
-      protected ServerName[] getCurrentServers() throws IOException {
+      protected ServerName[] getCurrentServers() {
         final int count = 4;
         List<ServerName> serverNames = new ArrayList<>(count);
         for (int i = 0; i < 4; i++) {
           serverNames.add(ServerName.valueOf(i + ".example.org", i, i));
         }
-        return serverNames.toArray(new ServerName[serverNames.size()]);
+        return serverNames.toArray(new ServerName[0]);
       }
 
       @Override
       protected void killRs(ServerName server) throws IOException {
-        LOG.info("Killed " + server);
+        LOG.info("Killed {}", server);
         if (this.invocations++ % 3 == 0) {
           throw new org.apache.hadoop.util.Shell.ExitCodeException(-1, "Failed");
         }
@@ -147,7 +148,7 @@ public class RollingBatchRestartRsAction extends BatchRestartRsAction {
 
       @Override
       protected void startRs(ServerName server) throws IOException {
-        LOG.info("Started " + server);
+        LOG.info("Started {}", server);
         if (this.invocations++ % 3 == 0) {
           throw new org.apache.hadoop.util.Shell.ExitCodeException(-1, "Failed");
         }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/RollingBatchSuspendResumeRsAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -22,7 +22,6 @@ import java.io.IOException;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Queue;
-
 import org.apache.commons.lang3.RandomUtils;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
@@ -40,9 +39,9 @@ import org.slf4j.LoggerFactory;
 public class RollingBatchSuspendResumeRsAction extends Action {
   private static final Logger LOG =
       LoggerFactory.getLogger(RollingBatchSuspendResumeRsAction.class);
-  private float ratio;
+  private final float ratio;
-  private long sleepTime;
+  private final long sleepTime;
-  private int maxSuspendedServers; // number of maximum suspended servers at any given time.
+  private final int maxSuspendedServers; // number of maximum suspended servers at any given time.
 
   public RollingBatchSuspendResumeRsAction(long sleepTime, float ratio) {
     this(sleepTime, ratio, 5);
@@ -58,10 +57,14 @@ public class RollingBatchSuspendResumeRsAction extends Action {
     SUSPEND, RESUME
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info(String.format("Performing action: Rolling batch restarting %d%% of region servers",
+    getLogger().info("Performing action: Rolling batch restarting {}% of region servers",
-        (int) (ratio * 100)));
+      (int) (ratio * 100));
     List<ServerName> selectedServers = selectServers();
 
     Queue<ServerName> serversToBeSuspended = new LinkedList<>(selectedServers);
@@ -70,8 +73,8 @@ public class RollingBatchSuspendResumeRsAction extends Action {
     // loop while there are servers to be suspended or suspended servers to be resumed
     while ((!serversToBeSuspended.isEmpty() || !suspendedServers.isEmpty()) && !context
         .isStopping()) {
-      SuspendOrResume action;
 
+      final SuspendOrResume action;
       if (serversToBeSuspended.isEmpty()) { // no more servers to suspend
         action = SuspendOrResume.RESUME;
       } else if (suspendedServers.isEmpty()) {
@@ -105,7 +108,7 @@ public class RollingBatchSuspendResumeRsAction extends Action {
           break;
       }
 
-      LOG.info("Sleeping for:{}", sleepTime);
+      getLogger().info("Sleeping for:{}", sleepTime);
       Threads.sleep(sleepTime);
     }
   }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/SnapshotTableAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -28,8 +28,7 @@ import org.slf4j.LoggerFactory;
 * Action that tries to take a snapshot of a table.
 */
 public class SnapshotTableAction extends Action {
-  private static final Logger LOG =
+  private static final Logger LOG = LoggerFactory.getLogger(SnapshotTableAction.class);
-      LoggerFactory.getLogger(SnapshotTableAction.class);
   private final TableName tableName;
   private final long sleepTime;
 
@@ -42,6 +41,10 @@ public class SnapshotTableAction extends Action {
     this.sleepTime = sleepTime;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     HBaseTestingUtility util = context.getHBaseIntegrationTestingUtility();
@@ -53,7 +56,7 @@ public class SnapshotTableAction extends Action {
       return;
     }
 
-    LOG.info("Performing action: Snapshot table " + tableName);
+    getLogger().info("Performing action: Snapshot table {}", tableName);
     admin.snapshot(snapshotName, tableName);
     if (sleepTime > 0) {
       Thread.sleep(sleepTime);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/SplitAllRegionOfTableAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,14 +19,12 @@ package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
 import java.util.concurrent.ThreadLocalRandom;
-
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.Admin;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-
 public class SplitAllRegionOfTableAction extends Action {
   private static final Logger LOG =
       LoggerFactory.getLogger(SplitAllRegionOfTableAction.class);
@@ -47,6 +45,10 @@ public class SplitAllRegionOfTableAction extends Action {
     this.maxFullTableSplits = getConf().getInt(MAX_SPLIT_KEY, DEFAULT_MAX_SPLITS);
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     HBaseTestingUtility util = context.getHBaseIntegrationTestingUtility();
@@ -61,10 +63,10 @@ public class SplitAllRegionOfTableAction extends Action {
     if (ThreadLocalRandom.current().nextDouble()
         < (((double) splits) / ((double) maxFullTableSplits)) / ((double) 2)) {
       splits++;
-      LOG.info("Performing action: Split all regions of  " + tableName);
+      getLogger().info("Performing action: Split all regions of {}", tableName);
       admin.split(tableName);
     } else {
-      LOG.info("Skipping split of all regions.");
+      getLogger().info("Skipping split of all regions.");
     }
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/SplitRandomRegionOfTableAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.util.List;
-
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
@@ -46,15 +45,19 @@ public class SplitRandomRegionOfTableAction extends Action {
     this.tableName = tableName;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     HBaseTestingUtility util = context.getHBaseIntegrationTestingUtility();
     Admin admin = util.getAdmin();
 
-    LOG.info("Performing action: Split random region of table " + tableName);
+    getLogger().info("Performing action: Split random region of table " + tableName);
     List<RegionInfo> regions = admin.getRegions(tableName);
     if (regions == null || regions.isEmpty()) {
-      LOG.info("Table " + tableName + " doesn't have regions to split");
+      getLogger().info("Table " + tableName + " doesn't have regions to split");
       return;
     }
     // Don't try the split if we're stopping
@@ -63,12 +66,12 @@ public class SplitRandomRegionOfTableAction extends Action {
     }
 
     RegionInfo region = PolicyBasedChaosMonkey.selectRandomItem(
-        regions.toArray(new RegionInfo[regions.size()]));
+        regions.toArray(new RegionInfo[0]));
-    LOG.debug("Splitting region " + region.getRegionNameAsString());
+    getLogger().debug("Splitting region " + region.getRegionNameAsString());
     try {
       admin.splitRegionAsync(region.getRegionName()).get();
     } catch (Exception ex) {
-      LOG.warn("Split failed, might be caused by other chaos: " + ex.getMessage());
+      getLogger().warn("Split failed, might be caused by other chaos: " + ex.getMessage());
     }
     if (sleepTime > 0) {
       Thread.sleep(sleepTime);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/SudoCommandAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,18 +19,14 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.io.IOException;
-
 import org.apache.hadoop.hbase.DistributedHBaseCluster;
 import org.apache.hadoop.hbase.HBaseCluster;
 import org.apache.hadoop.hbase.HBaseClusterManager;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /**
  * Base class for performing Actions based on linux commands requiring sudo privileges
  */
 abstract public class SudoCommandAction extends Action {
-  private static final Logger LOG = LoggerFactory.getLogger(SudoCommandAction.class);
 
   protected long timeout;
   protected HBaseClusterManager clusterManager;
@@ -43,9 +39,9 @@ abstract public class SudoCommandAction extends Action {
   public void init(ActionContext context) throws IOException {
     super.init(context);
     HBaseCluster cluster = context.getHBaseCluster();
-    if(cluster != null && cluster instanceof DistributedHBaseCluster){
+    if (cluster instanceof DistributedHBaseCluster){
       Object manager = ((DistributedHBaseCluster)cluster).getClusterManager();
-      if(manager != null && manager instanceof HBaseClusterManager){
+      if (manager instanceof HBaseClusterManager){
         clusterManager = (HBaseClusterManager) manager;
       }
     }
@@ -54,7 +50,7 @@ abstract public class SudoCommandAction extends Action {
   @Override
   public void perform() throws Exception {
     if (clusterManager == null){
-      LOG.info("Couldn't perform command action, it requires a distributed cluster.");
+      getLogger().info("Couldn't perform command action, it requires a distributed cluster.");
       return;
     }
 

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/TestChangeSplitPolicyAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -33,16 +33,14 @@ import org.junit.experimental.categories.Category;
 import org.mockito.Mockito;
 
 @Category({MediumTests.class})
-public class TestChangeSplitPolicyAction extends Action {
+public class TestChangeSplitPolicyAction {
 
   @ClassRule
   public static final HBaseClassTestRule CLASS_RULE =
       HBaseClassTestRule.forClass(TestChangeSplitPolicyAction.class);
 
   private final static IntegrationTestingUtility TEST_UTIL = new IntegrationTestingUtility();
-  private static ChangeSplitPolicyAction action;
+  private final TableName tableName = TableName.valueOf("ChangeSplitPolicyAction");
-  private Admin admin;
-  private TableName tableName = TableName.valueOf("ChangeSplitPolicyAction");
 
   @BeforeClass
   public static void setUpBeforeClass() throws Exception {
@@ -54,17 +52,17 @@ public class TestChangeSplitPolicyAction extends Action {
   }
   @Before
   public void setUp() throws Exception {
-    this.admin = TEST_UTIL.getAdmin();
+    Admin admin = TEST_UTIL.getAdmin();
     TableDescriptorBuilder builder = TableDescriptorBuilder.newBuilder(tableName);
     admin.createTable(builder.setColumnFamily(ColumnFamilyDescriptorBuilder.of("fam")).build());
   }
 
   @Test
   public void testChangeSplitPolicyAction() throws Exception {
-    ActionContext ctx = Mockito.mock(ActionContext.class);
+    Action.ActionContext ctx = Mockito.mock(Action.ActionContext.class);
     Mockito.when(ctx.getHBaseIntegrationTestingUtility()).thenReturn(TEST_UTIL);
     Mockito.when(ctx.getHBaseCluster()).thenReturn(TEST_UTIL.getHBaseCluster());
-    action = new ChangeSplitPolicyAction(tableName);
+    ChangeSplitPolicyAction action = new ChangeSplitPolicyAction(tableName);
     action.init(ctx);
     action.perform();
   }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/TruncateTableAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.chaos.actions;
 
 import java.util.Random;
-
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.Admin;
@@ -30,8 +29,7 @@ import org.slf4j.LoggerFactory;
  * Action that tries to truncate of a table.
  */
 public class TruncateTableAction extends Action {
-  private static final Logger LOG =
+  private static final Logger LOG = LoggerFactory.getLogger(TruncateTableAction.class);
-      LoggerFactory.getLogger(TruncateTableAction.class);
   private final TableName tableName;
   private final Random random;
 
@@ -40,6 +38,10 @@ public class TruncateTableAction extends Action {
     this.random = new Random();
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     HBaseTestingUtility util = context.getHBaseIntegrationTestingUtility();
@@ -51,8 +53,8 @@ public class TruncateTableAction extends Action {
     }
 
     boolean preserveSplits = random.nextBoolean();
-    LOG.info("Performing action: Truncate table " + tableName.getNameAsString() +
+    getLogger().info("Performing action: Truncate table {} preserve splits {}",
-             "preserve splits " + preserveSplits);
+      tableName.getNameAsString(), preserveSplits);
     admin.truncateTable(tableName, preserveSplits);
   }
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/UnbalanceKillAndRebalanceAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -23,7 +23,6 @@ import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
-
 import org.apache.commons.lang3.RandomUtils;
 import org.apache.hadoop.hbase.ClusterMetrics;
 import org.apache.hadoop.hbase.ServerName;
@@ -42,10 +41,10 @@ public class UnbalanceKillAndRebalanceAction extends Action {
   private static final double HOARD_FRC_OF_REGIONS = 0.8;
   /** Waits between calling unbalance and killing servers, kills and rebalance, and rebalance
    * and restarting the servers; to make sure these events have time to impact the cluster. */
-  private long waitForUnbalanceMilliSec;
+  private final long waitForUnbalanceMilliSec;
-  private long waitForKillsMilliSec;
+  private final long waitForKillsMilliSec;
-  private long waitAfterBalanceMilliSec;
+  private final long waitAfterBalanceMilliSec;
-  private boolean killMetaRs;
+  private final boolean killMetaRs;
 
   public UnbalanceKillAndRebalanceAction(long waitUnbalance, long waitKill, long waitAfterBalance,
       boolean killMetaRs) {
@@ -56,6 +55,10 @@ public class UnbalanceKillAndRebalanceAction extends Action {
     this.killMetaRs = killMetaRs;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
     ClusterMetrics status = this.cluster.getClusterMetrics();
@@ -86,7 +89,7 @@ public class UnbalanceKillAndRebalanceAction extends Action {
       }
 
       if (!killMetaRs && targetServer.equals(metaServer)) {
-        LOG.info("Not killing server because it holds hbase:meta.");
+        getLogger().info("Not killing server because it holds hbase:meta.");
       } else {
         killRs(targetServer);
         killedServers.add(targetServer);

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/UnbalanceRegionsAction.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -21,7 +21,6 @@ package org.apache.hadoop.hbase.chaos.actions;
 import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
-
 import org.apache.commons.lang3.RandomUtils;
 import org.apache.hadoop.hbase.ClusterMetrics;
 import org.apache.hadoop.hbase.ServerName;
@@ -32,10 +31,9 @@ import org.slf4j.LoggerFactory;
 * Action that tries to unbalance the regions of a cluster.
 */
 public class UnbalanceRegionsAction extends Action {
-  private static final Logger LOG =
+  private static final Logger LOG = LoggerFactory.getLogger(UnbalanceRegionsAction.class);
-      LoggerFactory.getLogger(UnbalanceRegionsAction.class);
+  private final double fractionOfRegions;
-  private double fractionOfRegions;
+  private final double fractionOfServers;
-  private double fractionOfServers;
 
   /**
    * Unbalances the regions on the cluster by choosing "target" servers, and moving
@@ -48,9 +46,13 @@ public class UnbalanceRegionsAction extends Action {
     this.fractionOfServers = fractionOfServers;
   }
 
+  @Override protected Logger getLogger() {
+    return LOG;
+  }
+
   @Override
   public void perform() throws Exception {
-    LOG.info("Unbalancing regions");
+    getLogger().info("Unbalancing regions");
     ClusterMetrics status = this.cluster.getClusterMetrics();
     List<ServerName> victimServers = new LinkedList<>(status.getLiveServerMetrics().keySet());
     int targetServerCount = (int)Math.ceil(fractionOfServers * victimServers.size());

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/policies/CompositeSequentialPolicy.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -23,7 +23,7 @@ import java.util.List;
 
 /** A policy that runs multiple other policies one after the other */
 public class CompositeSequentialPolicy extends Policy {
-  private List<Policy> policies;
+  private final List<Policy> policies;
   public CompositeSequentialPolicy(Policy... policies) {
     this.policies = Arrays.asList(policies);
   }