Add zero-allocation deployments to best plan logging

Author: jan-elastic

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/inference/assignment/planning/AssignmentPlan.java

@@ -344,7 +344,12 @@ public String prettyPrint() {
         }
 
         Map<Node, List<Tuple<Deployment, Integer>>> nodeToModel = new HashMap<>();
+        Set<Deployment> zeroAllocationsDeployments = new HashSet<>();
         for (Deployment m : assignments.keySet()) {
+            if (assignments.get(m).isEmpty()) {
+                zeroAllocationsDeployments.add(m);
+                continue;
+            }
             for (Node n : assignments.get(m).keySet()) {
                 List<Tuple<Deployment, Integer>> allocationsPerModel = nodeToModel.containsKey(n) ? nodeToModel.get(n) : new ArrayList<>();
                 allocationsPerModel.add(Tuple.tuple(m, assignments.get(m).get(n)));
@@ -382,6 +387,11 @@ public String prettyPrint() {
                 msg.append('\n');
             }
         }
+        if (zeroAllocationsDeployments.isEmpty() == false) {
+            msg.append('\n');
+            msg.append("Deployments with zero allocations: ");
+            msg.append(zeroAllocationsDeployments.stream().map(Deployment::deploymentId).collect(Collectors.joining(", ", "[", "]")));
+        }
         return msg.toString();
     }
 

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/inference/assignment/planning/AssignmentPlanner.java

@@ -102,10 +102,12 @@ public AssignmentPlan computePlan(boolean tryAssigningAllPreviouslyAllocatedMode
             }
         }
 
-        logger.debug(() -> "Best plan =\n" + bestPlan.prettyPrint());
-        logger.debug(() -> prettyPrintOverallStats(bestPlan));
-
-        return bestPlan.withZeroAllocationDeployments(deploymentsWithZeroAllocations);
+        bestPlan = bestPlan.withZeroAllocationDeployments(deploymentsWithZeroAllocations);
+        if (logger.isDebugEnabled()) {
+            logger.debug("Best plan =\n{}", bestPlan.prettyPrint());
+            logger.debug("{}", prettyPrintOverallStats(bestPlan));
+        }
+        return bestPlan;
     }
 
     /**