fix scalar resource accounting for single lease mode (#186)

Author: corindwyer

fenzo-core/src/main/java/com/netflix/fenzo/AssignableVirtualMachine.java

@@ -555,17 +555,25 @@ private void removeResourcesOf(TaskRequest request) {
         currTotalNetworkMbps -= request.getNetworkMbps();
         final Map<String, Double> scalarRequests = request.getScalarRequests();
         if(scalarRequests != null && !scalarRequests.isEmpty()) {
-            for(Map.Entry<String, Double> entry: scalarRequests.entrySet()) {
+            for (Map.Entry<String, Double> entry : scalarRequests.entrySet()) {
                 Double oldVal = currTotalScalars.get(entry.getKey());
-                if(oldVal != null) {
-                    double newVal = oldVal - entry.getValue();
-                    if(newVal < 0.0) {
-                        logger.warn(hostname + ": Scalar resource " + entry.getKey() + " is " + newVal + " after removing " +
-                                entry.getValue() + " from task " + request.getId());
-                        currTotalScalars.put(entry.getKey(), 0.0);
+                if (singleLeaseMode) {
+                    // resources must be able to be negative in single lease mode
+                    if (oldVal == null) {
+                        oldVal = 0.0;
+                    }
+                    currTotalScalars.put(entry.getKey(), oldVal - entry.getValue());
+                } else {
+                    if (oldVal != null) {
+                        double newVal = oldVal - entry.getValue();
+                        if (newVal < 0.0) {
+                            logger.warn(hostname + ": Scalar resource " + entry.getKey() + " is " + newVal + " after removing " +
+                                    entry.getValue() + " from task " + request.getId());
+                            currTotalScalars.put(entry.getKey(), 0.0);
+                        } else {
+                            currTotalScalars.put(entry.getKey(), newVal);
+                        }
                     }
-                    else
-                        currTotalScalars.put(entry.getKey(), newVal);
                 }
             }
         }

fenzo-core/src/test/java/com/netflix/fenzo/ScalarResourceTests.java

@@ -25,8 +25,13 @@
 public class ScalarResourceTests {
 
     private TaskScheduler getScheduler() {
+        return getScheduler(false);
+    }
+
+    private TaskScheduler getScheduler(boolean singleLeaseMode) {
         return new TaskScheduler.Builder()
                 .withLeaseOfferExpirySecs(1000000)
+                .withSingleOfferPerVM(singleLeaseMode)
                 .withLeaseRejectAction(new Action1<VirtualMachineLease>() {
                     @Override
                     public void call(VirtualMachineLease virtualMachineLease) {
@@ -131,4 +136,18 @@ public void testMultipleScalarResources() throws Exception {
         }
         Assert.assertEquals((int)(scalars2OnHost*2.0), tasksAssigned);
     }
+
+    @Test
+    public void testInsufficientScalarResourcesWithSingleLeaseMode() {
+        final TaskScheduler scheduler = getScheduler(true);
+        final double scalarsOnHost=4.0;
+        final TaskRequest task = TaskRequestProvider.getTaskRequest(null, 1, 100, 1, 1, 1, null, null, null, Collections.singletonMap("gpu", scalarsOnHost+1.0));
+        final VirtualMachineLease host1 = LeaseProvider.getLeaseOffer("host1", 4.0, 4000.0, 100, 1024,
+                Collections.singletonList(new VirtualMachineLease.Range(1, 10)), null, Collections.singletonMap("gpu", scalarsOnHost));
+        final SchedulingResult result = scheduler.scheduleOnce(Collections.singletonList(task), Collections.singletonList(host1));
+        Assert.assertEquals(1, result.getFailures().size());
+        Assert.assertEquals(0, result.getResultMap().size());
+        Assert.assertEquals(VMResource.Other, result.getFailures().values().iterator().next().get(0).getFailures().get(0).getResource());
+        System.out.println(result.getFailures().values().iterator().next().get(0).getFailures().get(0));
+    }
 }