Reduce dns lookup overhead on NodeScheduler

It does not need to dns lookup for hostname if HostAddress has port, which incurred additional overhead when dns too slow on some host environment.
trinodb · Aug 7, 2023 · 4cacdb8 · 4cacdb8
1 parent 55fa990
commit 4cacdb8
Showing 1 changed file with 18 additions and 18 deletions.
diff --git a/core/trino-main/src/main/java/io/trino/execution/scheduler/NodeScheduler.java b/core/trino-main/src/main/java/io/trino/execution/scheduler/NodeScheduler.java
@@ -107,17 +107,17 @@ public static List<InternalNode> selectExactNodes(NodeMap nodeMap, List<HostAddr
                     .filter(node -> includeCoordinator || !coordinatorIds.contains(node.getNodeIdentifier()))
                     .forEach(chosen::add);
 
-            InetAddress address;
-            try {
-                address = host.toInetAddress();
-            }
-            catch (UnknownHostException e) {
-                // skip hosts that don't resolve
-                continue;
-            }
-
             // consider a split with a host without a port as being accessible by all nodes in that host
             if (!host.hasPort()) {
+                InetAddress address;
+                try {
+                    address = host.toInetAddress();
+                }
+                catch (UnknownHostException e) {
+                    // skip hosts that don't resolve
+                    continue;
+                }
+
                 nodeMap.getNodesByHost().get(address).stream()
                         .filter(node -> includeCoordinator || !coordinatorIds.contains(node.getNodeIdentifier()))
                         .forEach(chosen::add);
@@ -133,17 +133,17 @@ public static List<InternalNode> selectExactNodes(NodeMap nodeMap, List<HostAddr
 
                 chosen.addAll(nodeMap.getNodesByHostAndPort().get(host));
 
-                InetAddress address;
-                try {
-                    address = host.toInetAddress();
-                }
-                catch (UnknownHostException e) {
-                    // skip hosts that don't resolve
-                    continue;
-                }
-
                 // consider a split with a host without a port as being accessible by all nodes in that host
                 if (!host.hasPort()) {
+                    InetAddress address;
+                    try {
+                        address = host.toInetAddress();
+                    }
+                    catch (UnknownHostException e) {
+                        // skip hosts that don't resolve
+                        continue;
+                    }
+
                     chosen.addAll(nodeMap.getNodesByHost().get(address));
                 }
             }