HADOOP-12175. FsShell must load SpanReceierHost to support tracing (Masatake Iwasaki via Colin P. McCabe)

(cherry picked from commit 69b095730bd87706ddcbabeea6c513290ee4cdf5)

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -526,6 +526,9 @@ Release 2.8.0 - UNRELEASED
     HADOOP-12245. References to misspelled REMAINING_QUATA in
     FileSystemShell.md. (Gabor Liptak via aajisaka)
 
+    HADOOP-12175. FsShell must load SpanReceierHost to support tracing
+    (Masatake Iwasaki via Colin P. McCabe)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FsShell.java

@@ -32,6 +32,7 @@ import org.apache.hadoop.conf.Configured;
 import org.apache.hadoop.fs.shell.Command;
 import org.apache.hadoop.fs.shell.CommandFactory;
 import org.apache.hadoop.fs.shell.FsCommand;
+import org.apache.hadoop.tracing.SpanReceiverHost;
 import org.apache.hadoop.tools.TableListing;
 import org.apache.hadoop.tracing.TraceUtils;
 import org.apache.hadoop.util.Tool;
@@ -57,6 +58,9 @@ public class FsShell extends Configured implements Tool {
   private final String usagePrefix =
     "Usage: hadoop fs [generic options]";
 
+  private SpanReceiverHost spanReceiverHost;
+  static final String SEHLL_HTRACE_PREFIX = "dfs.shell.htrace.";
+
   /**
    * Default ctor with no configuration.  Be sure to invoke
    * {@link #setConf(Configuration)} with a valid configuration prior
@@ -97,6 +101,8 @@ public class FsShell extends Configured implements Tool {
       commandFactory.addObject(new Usage(), "-usage");
       registerCommands(commandFactory);
     }
+    this.spanReceiverHost =
+        SpanReceiverHost.get(getConf(), SEHLL_HTRACE_PREFIX);
   }
 
   protected void registerCommands(CommandFactory factory) {
@@ -279,7 +285,7 @@ public class FsShell extends Configured implements Tool {
     // initialize FsShell
     init();
     traceSampler = new SamplerBuilder(TraceUtils.
-        wrapHadoopConf("dfs.shell.htrace.", getConf())).build();
+        wrapHadoopConf(SEHLL_HTRACE_PREFIX, getConf())).build();
     int exitCode = -1;
     if (argv.length < 1) {
       printUsage(System.err);
@@ -335,6 +341,9 @@ public class FsShell extends Configured implements Tool {
       fs.close();
       fs = null;
     }
+    if (this.spanReceiverHost != null) {
+      this.spanReceiverHost.closeReceivers();
+    }
   }
 
   /**

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestFsShell.java

@@ -18,6 +18,12 @@
 package org.apache.hadoop.fs;
 
 import junit.framework.AssertionFailedError;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.tracing.SetSpanReceiver;
+import org.apache.hadoop.tracing.SpanReceiverHost;
+import org.apache.hadoop.util.ToolRunner;
+import org.apache.htrace.SamplerBuilder;
+import org.apache.htrace.impl.AlwaysSampler;
 import org.junit.Test;
 
 public class TestFsShell {
@@ -39,4 +45,22 @@ public class TestFsShell {
     }
   }
 
+  @Test
+  public void testTracing() throws Throwable {
+    Configuration conf = new Configuration();
+    String prefix = FsShell.SEHLL_HTRACE_PREFIX;
+    conf.set(prefix + SpanReceiverHost.SPAN_RECEIVERS_CONF_SUFFIX,
+        SetSpanReceiver.class.getName());
+    conf.set(prefix + SamplerBuilder.SAMPLER_CONF_KEY,
+        AlwaysSampler.class.getName());
+    conf.setQuietMode(false);
+    FsShell shell = new FsShell(conf);
+    int res;
+    try {
+      res = ToolRunner.run(shell, new String[]{"-help"});
+    } finally {
+      shell.close();
+    }
+    SetSpanReceiver.assertSpanNamesFound(new String[]{"help"});
+  }
 }

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/tracing/SetSpanReceiver.java

@@ -86,7 +86,7 @@ public class SetSpanReceiver implements SpanReceiver {
     }
   }
 
-  static void assertSpanNamesFound(final String[] expectedSpanNames) {
+  public static void assertSpanNamesFound(final String[] expectedSpanNames) {
     try {
       GenericTestUtils.waitFor(new Supplier<Boolean>() {
         @Override