HBASE-25867 Extra doc around ITBLL (#3242)

* HBASE-25867 Extra doc around ITBLL

Minor edits to a few log messages.
Explain how the '-c' option works when passed to ChaosMonkeyRunner.
Some added notes on ITBLL.
Fix whacky 'R' and 'Not r' thing in Master (shows when you run ITBLL).
In HRS, report hostname and port when it checks in (was debugging issue
where Master and HRS had different notions of its hostname).
Spare a dirty FNFException on startup if base dir not yet in place.

* Address Review by Sean

Signed-off-by: Sean Busbey <busbey@apache.org>

hbase-it/src/test/java/org/apache/hadoop/hbase/DistributedHBaseCluster.java

@@ -243,7 +243,7 @@ public class DistributedHBaseCluster extends HBaseCluster {
       }
       Threads.sleep(100);
     }
-    throw new IOException("did timeout waiting for service to stop:" + serverName);
+    throw new IOException("Timed-out waiting for service to stop: " + serverName);
   }
 
   private void waitForServiceToStart(ServiceType service, ServerName serverName, long timeout)
@@ -257,7 +257,7 @@ public class DistributedHBaseCluster extends HBaseCluster {
       }
       Threads.sleep(100);
     }
-    throw new IOException("did timeout waiting for service to start:" + serverName);
+    throw new IOException("Timed-out waiting for service to start: " + serverName);
   }
 
   @Override

hbase-it/src/test/java/org/apache/hadoop/hbase/IntegrationTestingUtility.java

@@ -58,8 +58,9 @@ public class IntegrationTestingUtility extends HBaseTestingUtility {
    */
   public static final String IS_DISTRIBUTED_CLUSTER = "hbase.test.cluster.distributed";
 
-  /** Config for pluggable hbase cluster manager */
+  /** Config for pluggable hbase cluster manager. Pass fully-qualified class name as property
-  private static final String HBASE_CLUSTER_MANAGER_CLASS = "hbase.it.clustermanager.class";
+   * value. Drop the '.class' suffix.*/
+  public static final String HBASE_CLUSTER_MANAGER_CLASS = "hbase.it.clustermanager.class";
   private static final Class<? extends ClusterManager> DEFAULT_HBASE_CLUSTER_MANAGER_CLASS =
     HBaseClusterManager.class;
 
@@ -153,5 +154,4 @@ public class IntegrationTestingUtility extends HBaseTestingUtility {
     setHBaseCluster(new DistributedHBaseCluster(conf, clusterManager));
     getAdmin();
   }
-
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/util/ChaosMonkeyRunner.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
@@ -38,12 +38,10 @@ import org.apache.hbase.thirdparty.org.apache.commons.cli.CommandLine;
 
 public class ChaosMonkeyRunner extends AbstractHBaseTool {
   private static final Logger LOG = LoggerFactory.getLogger(ChaosMonkeyRunner.class);
-
   public static final String MONKEY_LONG_OPT = "monkey";
   public static final String CHAOS_MONKEY_PROPS = "monkeyProps";
   public static final String TABLE_NAME_OPT = "tableName";
   public static final String FAMILY_NAME_OPT = "familyName";
-
   protected IntegrationTestingUtility util;
   protected ChaosMonkey monkey;
   protected String monkeyToUse;
@@ -54,6 +52,9 @@ public class ChaosMonkeyRunner extends AbstractHBaseTool {
 
   @Override
   public void addOptions() {
+    // The -c option is processed down in the main, not along w/ other options. Added here so shows
+    // in the usage output.
+    addOptWithArg("c", "Name of extra configurations file to find on CLASSPATH");
     addOptWithArg("m", MONKEY_LONG_OPT, "Which chaos monkey to run");
     addOptWithArg(CHAOS_MONKEY_PROPS, "The properties file for specifying chaos "
         + "monkey properties.");
@@ -168,9 +169,22 @@ public class ChaosMonkeyRunner extends AbstractHBaseTool {
   }
 
   /*
-   * If caller wants to add config parameters contained in a file, the path of conf file
+   * If caller wants to add config parameters from a file, the path to the conf file
-   * can be passed as the first two arguments like this:
+   * can be passed like this: -c <path-to-conf>. The file is presumed to have the Configuration
-   *   -c <path-to-conf>
+   * file xml format and is added as a new Resource to the current Configuration.
+   * Use this mechanism to set Configuration such as what ClusterManager to use, etc.
+   * Here is an example file you might references that sets an alternate ClusterManager:
+   * {code}
+   * <?xml version="1.0" encoding="UTF-8"?>
+   * <configuration>
+   *   <property>
+   *     <name>hbase.it.clustermanager.class</name>
+   *     <value>org.apache.hadoop.hbase.MyCustomClusterManager</value>
+   *   </property>
+   * </configuration>
+   * {code}
+   * NOTE: The code searches for the file name passed on the CLASSPATH! Passing the path to a file
+   * will not work! Add the file to the CLASSPATH and then pass the filename as the '-c' arg.
    */
   public static void main(String[] args) throws Exception {
     Configuration conf = HBaseConfiguration.create();
@@ -180,7 +194,8 @@ public class ChaosMonkeyRunner extends AbstractHBaseTool {
       if (argCount < 0) {
         throw new IllegalArgumentException("Missing path for -c parameter");
       }
-      // load the resource specified by the second parameter
+      // Load the resource specified by the second parameter. We load from the classpath, not
+      // from filesystem path.
       conf.addResource(args[1]);
       actualArgs = new String[argCount];
       System.arraycopy(args, 2, actualArgs, 0, argCount);
@@ -189,5 +204,4 @@ public class ChaosMonkeyRunner extends AbstractHBaseTool {
     int ret = ToolRunner.run(conf, new ChaosMonkeyRunner(), actualArgs);
     System.exit(ret);
   }
-
 }

hbase-it/src/test/java/org/apache/hadoop/hbase/test/IntegrationTestBigLinkedList.java

@@ -152,11 +152,11 @@ import org.apache.hbase.thirdparty.org.apache.commons.cli.ParseException;
  * </p>
  * <p>
  * <ol>
- * <li>Write out 1 million nodes</li>
+ * <li>Write out 1 million nodes (1M is the configurable 'width' mentioned below)</li>
  * <li>Flush the client</li>
  * <li>Write out 1 million that reference previous million</li>
  * <li>If this is the 25th set of 1 million nodes, then update 1st set of
- * million to point to last</li>
+ * million to point to last (25 is configurable; its the 'wrap multiplier' referred to below)</li>
  * <li>goto 1</li>
  * </ol>
  * </p>
@@ -224,11 +224,8 @@ import org.apache.hbase.thirdparty.org.apache.commons.cli.ParseException;
 @Category(IntegrationTests.class)
 public class IntegrationTestBigLinkedList extends IntegrationTestBase {
   protected static final byte[] NO_KEY = new byte[1];
-
   protected static String TABLE_NAME_KEY = "IntegrationTestBigLinkedList.table";
-
   protected static String DEFAULT_TABLE_NAME = "IntegrationTestBigLinkedList";
-
   protected static byte[] FAMILY_NAME = Bytes.toBytes("meta");
   private static byte[] BIG_FAMILY_NAME = Bytes.toBytes("big");
   private static byte[] TINY_FAMILY_NAME = Bytes.toBytes("tiny");
@@ -263,6 +260,10 @@ public class IntegrationTestBigLinkedList extends IntegrationTestBase {
   private static final int MISSING_ROWS_TO_LOG = 10; // YARN complains when too many counters
 
   private static final int WIDTH_DEFAULT = 1000000;
+
+  /**
+   * The 'wrap multipler' default.
+   */
   private static final int WRAP_DEFAULT = 25;
   private static final int ROWKEY_LENGTH = 16;
 
@@ -282,7 +283,6 @@ public class IntegrationTestBigLinkedList extends IntegrationTestBase {
    * A Map only job that generates random linked list and stores them.
    */
   static class Generator extends Configured implements Tool {
-
     private static final Logger LOG = LoggerFactory.getLogger(Generator.class);
 
     /**
@@ -307,7 +307,6 @@ public class IntegrationTestBigLinkedList extends IntegrationTestBase {
      */
     public static final String BIG_FAMILY_VALUE_SIZE_KEY = "generator.big.family.value.size";
 
-
     public static enum Counts {
       SUCCESS, TERMINATING, UNDEFINED, IOEXCEPTION
     }
@@ -315,8 +314,11 @@ public class IntegrationTestBigLinkedList extends IntegrationTestBase {
     public static final String USAGE =  "Usage : " + Generator.class.getSimpleName() +
       " <num mappers> <num nodes per map> <tmp output dir> [<width> <wrap multiplier>" +
       " <num walker threads>] \n" +
-        "where <num nodes per map> should be a multiple of width*wrap multiplier, 25M by default \n" +
+      "Where <num nodes per map> should be a multiple of 'width' * 'wrap multiplier'.\n" +
-        "walkers will verify random flushed loop during Generation.";
+      "25M is default because default 'width' is 1M and default 'wrap multiplier' is 25.\n" +
+      "We write out 1M nodes and then flush the client. After 25 flushes, we connect \n" +
+      "first written nodes back to the 25th set.\n" +
+      "Walkers verify random flushed loops during Generation.";
 
     public Job job;
 
@@ -1089,17 +1091,14 @@ public class IntegrationTestBigLinkedList extends IntegrationTestBase {
    * {@link Generator} do not have any holes.
    */
   static class Verify extends Configured implements Tool {
-
     private static final Logger LOG = LoggerFactory.getLogger(Verify.class);
     protected static final BytesWritable DEF = new BytesWritable(new byte[] { 0 });
     protected static final BytesWritable DEF_LOST_FAMILIES = new BytesWritable(new byte[] { 1 });
-
     protected Job job;
 
     public static class VerifyMapper extends TableMapper<BytesWritable, BytesWritable> {
       private BytesWritable row = new BytesWritable();
       private BytesWritable ref = new BytesWritable();
-
       private boolean multipleUnevenColumnFamilies;
 
       @Override
@@ -1141,7 +1140,7 @@ public class IntegrationTestBigLinkedList extends IntegrationTestBase {
     }
 
     /**
-     * Per reducer, we output problem rows as byte arrasy so can be used as input for
+     * Per reducer, we output problem rows as byte arrays so can be used as input for
      * subsequent investigative mapreduce jobs. Each emitted value is prefaced by a one byte flag
      * saying what sort of emission it is. Flag is the Count enum ordinal as a short.
      */

hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java

@@ -1686,7 +1686,6 @@ public class HMaster extends HRegionServer implements MasterServices {
         // if hbase:meta region is in transition, result of assignment cannot be recorded
         // ignore the force flag in that case
         boolean metaInTransition = assignmentManager.isMetaRegionInTransition();
-        String prefix = force && !metaInTransition ? "R" : "Not r";
         List<RegionStateNode> toPrint = regionsInTransition;
         int max = 5;
         boolean truncated = false;
@@ -1694,9 +1693,12 @@ public class HMaster extends HRegionServer implements MasterServices {
           toPrint = regionsInTransition.subList(0, max);
           truncated = true;
         }
-        LOG.info(prefix + " not running balancer because " + regionsInTransition.size() +
+        if (!force || metaInTransition) {
-          " region(s) in transition: " + toPrint + (truncated? "(truncated list)": ""));
+          LOG.info("Not running balancer (force=" + force + ", metaRIT=" + metaInTransition +
-        if (!force || metaInTransition) return false;
+            ") because " + regionsInTransition.size() + " region(s) in transition: " + toPrint +
+            (truncated? "(truncated list)": ""));
+          return false;
+        }
       }
       if (this.serverManager.areDeadServersInProgress()) {
         LOG.info("Not running balancer because processing dead regionserver(s): " +

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java

@@ -480,7 +480,7 @@ public class HRegionServer extends Thread implements
     "hbase.regionserver.hostname.disable.master.reversedns";
 
   /**
-   * HBASE-18226: This config and hbase.unasfe.regionserver.hostname are mutually exclusive.
+   * HBASE-18226: This config and hbase.unsafe.regionserver.hostname are mutually exclusive.
    * Exception will be thrown if both are used.
    */
   @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)
@@ -2867,8 +2867,8 @@ public class HRegionServer extends Thread implements
       rpcServices.rpcFullScanRequestCount.reset();
       rpcServices.rpcMultiRequestCount.reset();
       rpcServices.rpcMutateRequestCount.reset();
-      LOG.info("reportForDuty to master=" + masterServerName + " with port="
+      LOG.info("reportForDuty to master=" + masterServerName + " with isa="
-        + rpcServices.isa.getPort() + ", startcode=" + this.startcode);
+        + rpcServices.isa + ", startcode=" + this.startcode);
       long now = EnvironmentEdgeManager.currentTime();
       int port = rpcServices.isa.getPort();
       RegionServerStartupRequest.Builder request = RegionServerStartupRequest.newBuilder();

hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSUtils.java

@@ -940,11 +940,12 @@ public final class FSUtils {
   public static List<Path> getTableDirs(final FileSystem fs, final Path rootdir)
       throws IOException {
     List<Path> tableDirs = new ArrayList<>();
-
+    Path baseNamespaceDir = new Path(rootdir, HConstants.BASE_NAMESPACE_DIR);
-    for (FileStatus status : fs
+    if (fs.exists(baseNamespaceDir)) {
-        .globStatus(new Path(rootdir, new Path(HConstants.BASE_NAMESPACE_DIR, "*")))) {
+      for (FileStatus status : fs.globStatus(new Path(baseNamespaceDir, "*"))) {
         tableDirs.addAll(FSUtils.getLocalTableDirs(fs, status.getPath()));
       }
+    }
     return tableDirs;
   }