Adding information about lost workers to REST API.

core/common/src/main/java/alluxio/wire/AlluxioMasterInfo.java

@@ -22,6 +22,7 @@
 public class AlluxioMasterInfo {
   private Capacity mCapacity;
   private Map<String, String> mConfiguration;
+  private List<WorkerInfo> mLostWorkers;
   private Map<String, Long> mMetrics;
   private Map<String, MountPointInfo> mMountPoints;
   private String mRpcAddress;
@@ -52,6 +53,13 @@ public Map<String, String> getConfiguration() {
     return mConfiguration;
   }
 
+  /**
+   * @return the list of lost workers
+   */
+  public List<WorkerInfo> getLostWorkers() {
+    return mLostWorkers;
+  }
+
   /**
    * @return the metrics
    */
@@ -140,6 +148,15 @@ public AlluxioMasterInfo setConfiguration(Map<String, String> configuration) {
     return this;
   }
 
+  /**
+   * @param lostWorkers the list of lost workers to use
+   * @return the Alluxio master information
+   */
+  public AlluxioMasterInfo setLostWorkers(List<WorkerInfo> lostWorkers) {
+    mLostWorkers = lostWorkers;
+    return this;
+  }
+
   /**
    * @param metrics the metrics to use
    * @return the Alluxio master information
@@ -241,6 +258,7 @@ public boolean equals(Object o) {
     AlluxioMasterInfo that = (AlluxioMasterInfo) o;
     return Objects.equal(mCapacity, that.mCapacity)
         && Objects.equal(mConfiguration, that.mConfiguration)
+        && Objects.equal(mLostWorkers, that.mLostWorkers)
         && Objects.equal(mMetrics, that.mMetrics)
         && Objects.equal(mMountPoints, that.mMountPoints)
         && Objects.equal(mRpcAddress, that.mRpcAddress)
@@ -256,16 +274,17 @@ public boolean equals(Object o) {
   @Override
   public int hashCode() {
     return Objects
-        .hashCode(mCapacity, mConfiguration, mMetrics, mMountPoints, mRpcAddress, mStartTimeMs,
-            mStartupConsistencyCheck, mTierCapacity, mUfsCapacity, mUptimeMs, mVersion,
-            mWorkers);
+        .hashCode(mCapacity, mConfiguration, mLostWorkers, mMetrics, mMountPoints, mRpcAddress,
+            mStartTimeMs, mStartupConsistencyCheck, mTierCapacity, mUfsCapacity, mUptimeMs,
+            mVersion, mWorkers);
   }
 
   @Override
   public String toString() {
     return Objects.toStringHelper(this)
         .add("capacity", mCapacity)
         .add("configuration", mConfiguration)
+        .add("lost workers", mLostWorkers)
         .add("metrics", mMetrics)
         .add("mount points", mMountPoints)
         .add("rpc address", mRpcAddress)
@@ -275,6 +294,7 @@ public String toString() {
         .add("ufs capacity", mUfsCapacity)
         .add("uptime", mUptimeMs)
         .add("version", mVersion)
-        .add("workers", mWorkers).toString();
+        .add("workers", mWorkers)
+        .toString();
   }
 }

core/common/src/test/java/alluxio/wire/AlluxioMasterInfoTest.java

@@ -43,6 +43,7 @@ public void equals() {
   private void checkEquality(AlluxioMasterInfo a, AlluxioMasterInfo b) {
     Assert.assertEquals(a.getCapacity(), b.getCapacity());
     Assert.assertEquals(a.getConfiguration(), b.getConfiguration());
+    Assert.assertEquals(a.getLostWorkers(), b.getLostWorkers());
     Assert.assertEquals(a.getMetrics(), b.getMetrics());
     Assert.assertEquals(a.getRpcAddress(), b.getRpcAddress());
     Assert.assertEquals(a.getStartTimeMs(), b.getStartTimeMs());
@@ -66,6 +67,11 @@ private static AlluxioMasterInfo createRandom() {
       configuration.put(CommonUtils.randomAlphaNumString(random.nextInt(10)),
           CommonUtils.randomAlphaNumString(random.nextInt(10)));
     }
+    List<WorkerInfo> lostWorkers = new ArrayList<>();
+    long numLostWorkers = random.nextInt(10);
+    for (int i = 0; i < numLostWorkers; i++) {
+      lostWorkers.add(WorkerInfoTest.createRandom());
+    }
     Map<String, Long> metrics = new HashMap<>();
     long numMetrics = random.nextInt(10);
     for (int i = 0; i < numMetrics; i++) {
@@ -98,6 +104,7 @@ private static AlluxioMasterInfo createRandom() {
 
     result.setCapacity(capacity);
     result.setConfiguration(configuration);
+    result.setLostWorkers(lostWorkers);
     result.setMetrics(metrics);
     result.setRpcAddress(rpcAddress);
     result.setStartTimeMs(startTimeMs);

core/server/src/main/java/alluxio/master/AlluxioMasterRestServiceHandler.java

@@ -126,6 +126,7 @@ public AlluxioMasterInfo call() throws Exception {
             new AlluxioMasterInfo()
                 .setCapacity(getCapacityInternal())
                 .setConfiguration(getConfigurationInternal(rawConfig))
+                .setLostWorkers(mBlockMaster.getLostWorkersInfoList())
                 .setMetrics(getMetricsInternal())
                 .setMountPoints(getMountPointsInternal())
                 .setRpcAddress(mMaster.getRpcAddress().toString())

core/server/src/main/java/alluxio/master/block/BlockMaster.java

@@ -310,8 +310,8 @@ public long getUsedBytes() {
    *
    * @return a set of worker info
    */
-  public Set<WorkerInfo> getLostWorkersInfo() {
-    Set<WorkerInfo> ret = new HashSet<>(mLostWorkers.size());
+  public List<WorkerInfo> getLostWorkersInfoList() {
+    List<WorkerInfo> ret = new ArrayList<>(mLostWorkers.size());
     for (MasterWorkerInfo worker : mLostWorkers) {
       synchronized (worker) {
         ret.add(worker.generateClientWorkerInfo());

core/server/src/main/java/alluxio/web/WebInterfaceWorkersServlet.java

@@ -23,7 +23,6 @@
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
-import java.util.Set;
 
 import javax.annotation.concurrent.ThreadSafe;
 import javax.servlet.ServletException;
@@ -223,7 +222,7 @@ private void populateValues(HttpServletRequest request) throws IOException {
     NodeInfo[] normalNodeInfos = generateOrderedNodeInfos(workerInfos);
     request.setAttribute("normalNodeInfos", normalNodeInfos);
 
-    Set<WorkerInfo> lostWorkerInfos = mBlockMaster.getLostWorkersInfo();
+    List<WorkerInfo> lostWorkerInfos = mBlockMaster.getLostWorkersInfoList();
     NodeInfo[] failedNodeInfos = generateOrderedNodeInfos(lostWorkerInfos);
     request.setAttribute("failedNodeInfos", failedNodeInfos);
   }

core/server/src/test/java/alluxio/master/block/BlockMasterTest.java

@@ -41,7 +41,6 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 
@@ -137,7 +136,7 @@ public void detectLostWorkers() throws Exception {
     HeartbeatScheduler.execute(HeartbeatContext.MASTER_LOST_WORKER_DETECTION);
 
     // Make sure the worker is detected as lost.
-    Set<WorkerInfo> info = mMaster.getLostWorkersInfo();
+    List<WorkerInfo> info = mMaster.getLostWorkersInfoList();
     Assert.assertEquals(worker1, Iterables.getOnlyElement(info).getId());
   }
 
@@ -167,7 +166,7 @@ public void workerReregisterRemembersLostWorker() throws Exception {
 
     // Check that there are no longer any lost workers and there is a live worker.
     Assert.assertEquals(1, mMaster.getWorkerCount());
-    Assert.assertEquals(0, mMaster.getLostWorkersInfo().size());
+    Assert.assertEquals(0, mMaster.getLostWorkersInfoList().size());
   }
 
   @Test

tests/src/test/java/alluxio/master/AlluxioMasterRestApiTest.java

@@ -104,6 +104,12 @@ private void checkConfiguration(PropertyKey key, String expectedValue, Map<Strin
     Assert.assertEquals(expectedValue, getInfo(params).getConfiguration().get(key.toString()));
   }
 
+  @Test
+  public void getLostWorkers() throws Exception {
+    List<WorkerInfo> lostWorkersInfo = getInfo(NO_PARAMS).getLostWorkers();
+    Assert.assertEquals(0, lostWorkersInfo.size());
+  }
+
   @Test
   public void getMetrics() throws Exception {
     Assert.assertEquals(Long.valueOf(0), getInfo(NO_PARAMS).getMetrics()