HADOOP-12201. Add tracing to FileSystem#createFileSystem and Globber#glob (cmccabe)

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

@@ -687,6 +687,9 @@ Release 2.8.0 - UNRELEASED
     HADOOP-12195. Add annotation to package-info.java file to workaround
     MCOMPILER-205. (wang)
 
+    HADOOP-12201. Add tracing to FileSystem#createFileSystem and Globber#glob
+    (cmccabe)
+
   OPTIMIZATIONS
 
     HADOOP-11785. Reduce the number of listStatus operation in distcp

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

@@ -67,6 +67,9 @@
 import org.apache.hadoop.util.ReflectionUtils;
 import org.apache.hadoop.util.ShutdownHookManager;
 import org.apache.hadoop.util.StringUtils;
+import org.apache.htrace.Span;
+import org.apache.htrace.Trace;
+import org.apache.htrace.TraceScope;
 
 import com.google.common.annotations.VisibleForTesting;
 
@@ -2675,10 +2678,19 @@ public static Class<? extends FileSystem> getFileSystemClass(String scheme,
 
   private static FileSystem createFileSystem(URI uri, Configuration conf
       ) throws IOException {
-    Class<?> clazz = getFileSystemClass(uri.getScheme(), conf);
+    TraceScope scope = Trace.startSpan("FileSystem#createFileSystem");
-    FileSystem fs = (FileSystem)ReflectionUtils.newInstance(clazz, conf);
+    Span span = scope.getSpan();
-    fs.initialize(uri, conf);
+    if (span != null) {
-    return fs;
+      span.addKVAnnotation("scheme", uri.getScheme());
+    }
+    try {
+      Class<?> clazz = getFileSystemClass(uri.getScheme(), conf);
+      FileSystem fs = (FileSystem)ReflectionUtils.newInstance(clazz, conf);
+      fs.initialize(uri, conf);
+      return fs;
+    } finally {
+      scope.close();
+    }
   }
 
   /** Caching FileSystem objects */

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

@@ -28,6 +28,10 @@
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 
+import org.apache.htrace.Span;
+import org.apache.htrace.Trace;
+import org.apache.htrace.TraceScope;
+
 @InterfaceAudience.Private
 @InterfaceStability.Unstable
 class Globber {
@@ -136,6 +140,19 @@ private String authorityFromPath(Path path) throws IOException {
   }
 
   public FileStatus[] glob() throws IOException {
+    TraceScope scope = Trace.startSpan("Globber#glob");
+    Span span = scope.getSpan();
+    if (span != null) {
+      span.addKVAnnotation("pattern", pathPattern.toUri().getPath());
+    }
+    try {
+      return doGlob();
+    } finally {
+      scope.close();
+    }
+  }
+
+  private FileStatus[] doGlob() throws IOException {
     // First we get the scheme and authority of the pattern that was passed
     // in.
     String scheme = schemeFromPath(pathPattern);