YARN-9694. UI always show default-rack for all the nodes while running SLS.

hadoop-tools/hadoop-sls/src/main/java/org/apache/hadoop/yarn/sls/SLSRunner.java

@@ -51,8 +51,11 @@
 import org.apache.hadoop.classification.InterfaceStability.Unstable;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.conf.Configured;
+import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.metrics2.source.JvmMetrics;
+import org.apache.hadoop.net.DNSToSwitchMapping;
+import org.apache.hadoop.net.TableMapping;
 import org.apache.hadoop.tools.rumen.JobTraceReader;
 import org.apache.hadoop.tools.rumen.LoggedJob;
 import org.apache.hadoop.tools.rumen.LoggedTask;
@@ -126,6 +129,7 @@ public class SLSRunner extends Configured implements Tool {
   // other simulation information
   private int numNMs, numRacks, numAMs, numTasks;
   private long maxRuntime;
+  private String tableMapping;
 
   private final static Map<String, Object> simulateInfoMap =
           new HashMap<String, Object>();
@@ -231,7 +235,7 @@ public void setSimulationParams(TraceType inType, String[] inTraces,
     this.trackedApps = trackApps;
     this.printSimulation = printsimulation;
     metricsOutputDir = outDir;
-
+    tableMapping = outDir + "/tableMapping.csv";
   }
 
   public void start() throws IOException, ClassNotFoundException, YarnException,
@@ -272,7 +276,12 @@ private void startRM() throws ClassNotFoundException, YarnException {
       // TODO add support for FifoScheduler
       throw new YarnException("Fifo Scheduler is not supported yet.");
     }
-
+    rmConf.setClass(
+        CommonConfigurationKeysPublic.NET_TOPOLOGY_NODE_SWITCH_MAPPING_IMPL_KEY,
+        TableMapping.class, DNSToSwitchMapping.class);
+    rmConf.set(
+        CommonConfigurationKeysPublic.NET_TOPOLOGY_TABLE_MAPPING_FILE_KEY,
+        tableMapping);
     rmConf.set(SLSConfiguration.METRICS_OUTPUT_DIR, metricsOutputDir);
 
     final SLSRunner se = this;
@@ -332,6 +341,8 @@ private void startNM() throws YarnException, IOException,
       throw new YarnException("No node! Please configure nodes.");
     }
 
+    SLSUtils.generateNodeTableMapping(nodeSet, tableMapping);
+
     // create NM simulators
     Random random = new Random();
     Set<String> rackSet = new ConcurrentHashSet<>();

hadoop-tools/hadoop-sls/src/main/java/org/apache/hadoop/yarn/sls/utils/SLSUtils.java

@@ -23,6 +23,11 @@
 import java.io.InputStreamReader;
 import java.io.Reader;
 
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.nio.file.StandardOpenOption;
+import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
@@ -219,4 +224,32 @@ public static Set<NodeDetails> generateNodes(int numNodes,
     }
     return nodeSet;
   }
+
+  /**
+   * Generates a node to rack mapping file based on node details.
+   * This file is then being used by TableMapping to resolve rack names.
+   * The format required by TableMapping is a two column text file
+   * where first column specifies node name
+   * and second column specifies rack name.
+   * @param nodeDetails Set of node details.
+   * @param filePath File path where to write table mapping.
+   * @throws IOException
+   */
+  public static void generateNodeTableMapping(Set<NodeDetails> nodeDetails,
+      String filePath) throws IOException {
+    List<String> entries = new ArrayList<>();
+    for (NodeDetails nodeDetail : nodeDetails) {
+      if (nodeDetail.getHostname().contains("/")) {
+        String hostname = nodeDetail.getHostname();
+        int lIndex = hostname.lastIndexOf("/");
+        String node = hostname.substring(lIndex + 1);
+        String rack = hostname.substring(0, lIndex);
+        entries.add(node + " " + rack);
+      }
+    }
+    Files.write(Paths.get(filePath),
+        entries,
+        StandardCharsets.UTF_8,
+        StandardOpenOption.CREATE);
+  }
 }

hadoop-tools/hadoop-sls/src/test/java/org/apache/hadoop/yarn/sls/utils/TestSLSUtils.java

@@ -24,7 +24,11 @@
 import org.junit.Assert;
 import org.junit.Test;
 
+import java.io.File;
+import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 
 public class TestSLSUtils {
@@ -109,6 +113,26 @@ public void testGenerateNodes() {
     Assert.assertEquals("Number of racks is wrong.", 1, getNumRack(nodes));
   }
 
+  /**
+   * Tests creation of table mapping based on given node details.
+   * @throws Exception
+   */
+  @Test
+  public void testGenerateNodeTableMapping() throws Exception {
+    Set<NodeDetails> nodes = SLSUtils.generateNodes(3, 3);
+    File tempFile = File.createTempFile("testslsutils", ".tmp");
+    tempFile.deleteOnExit();
+    String fileName = tempFile.getAbsolutePath();
+    SLSUtils.generateNodeTableMapping(nodes, fileName);
+
+    List<String> lines = Files.readAllLines(Paths.get(fileName));
+    Assert.assertEquals(3, lines.size());
+    for (String line : lines) {
+      Assert.assertTrue(line.contains("node"));
+      Assert.assertTrue(line.contains("/rack"));
+    }
+  }
+
   private int getNumRack(Set<NodeDetails> nodes) {
     Set<String> racks = new HashSet<>();
     for (NodeDetails node : nodes) {