diff --git a/server/src/main/java/org/elasticsearch/threadpool/ThreadPool.java b/server/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
index 6abdc309e21..c7d16d1979b 100644
--- a/server/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
+++ b/server/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
@@ -58,6 +58,7 @@ import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.ScheduledThreadPoolExecutor;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
 
 import static java.util.Collections.unmodifiableMap;
 
@@ -138,7 +139,9 @@ public class ThreadPool extends AbstractComponent implements Scheduler, Closeabl
         THREAD_POOL_TYPES = Collections.unmodifiableMap(map);
     }
 
-    private Map<String, ExecutorHolder> executors = new HashMap<>();
+    private final Map<String, ExecutorHolder> executors;
+
+    private final ThreadPoolInfo threadPoolInfo;
 
     private final CachedTimeThread cachedTimeThread;
 
@@ -207,6 +210,15 @@ public class ThreadPool extends AbstractComponent implements Scheduler, Closeabl
 
         executors.put(Names.SAME, new ExecutorHolder(DIRECT_EXECUTOR, new Info(Names.SAME, ThreadPoolType.DIRECT)));
         this.executors = unmodifiableMap(executors);
+
+        final List<Info> infos =
+                executors
+                        .values()
+                        .stream()
+                        .filter(holder -> holder.info.getName().equals("same") == false)
+                        .map(holder -> holder.info)
+                        .collect(Collectors.toList());
+        this.threadPoolInfo = new ThreadPoolInfo(infos);
         this.scheduler = Scheduler.initScheduler(settings);
         TimeValue estimatedTimeInterval = ESTIMATED_TIME_INTERVAL_SETTING.get(settings);
         this.cachedTimeThread = new CachedTimeThread(EsExecutors.threadName(settings, "[timer]"), estimatedTimeInterval.millis());
@@ -239,16 +251,7 @@ public class ThreadPool extends AbstractComponent implements Scheduler, Closeabl
     }
 
     public ThreadPoolInfo info() {
-        List<Info> infos = new ArrayList<>();
-        for (ExecutorHolder holder : executors.values()) {
-            String name = holder.info.getName();
-            // no need to have info on "same" thread pool
-            if ("same".equals(name)) {
-                continue;
-            }
-            infos.add(holder.info);
-        }
-        return new ThreadPoolInfo(infos);
+        return threadPoolInfo;
     }
 
     public Info info(String name) {
@@ -655,32 +658,29 @@ public class ThreadPool extends AbstractComponent implements Scheduler, Closeabl
         @Override
         public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
             builder.startObject(name);
-            builder.field(Fields.TYPE, type.getType());
-            if (min != -1) {
-                builder.field(Fields.MIN, min);
-            }
-            if (max != -1) {
-                builder.field(Fields.MAX, max);
+            builder.field("type", type.getType());
+
+            if (type == ThreadPoolType.SCALING) {
+                assert min != -1;
+                builder.field("core", min);
+                assert max != -1;
+                builder.field("max", max);
+            } else {
+                assert max != -1;
+                builder.field("size", max);
             }
             if (keepAlive != null) {
-                builder.field(Fields.KEEP_ALIVE, keepAlive.toString());
+                builder.field("keep_alive", keepAlive.toString());
             }
             if (queueSize == null) {
-                builder.field(Fields.QUEUE_SIZE, -1);
+                builder.field("queue_size", -1);
             } else {
-                builder.field(Fields.QUEUE_SIZE, queueSize.singles());
+                builder.field("queue_size", queueSize.singles());
             }
             builder.endObject();
             return builder;
         }
 
-        static final class Fields {
-            static final String TYPE = "type";
-            static final String MIN = "min";
-            static final String MAX = "max";
-            static final String KEEP_ALIVE = "keep_alive";
-            static final String QUEUE_SIZE = "queue_size";
-        }
     }
 
     /**