fix(config): align reference.conf defaults with develop runtime fallbacks

Address review feedback from 317787106 (2026-04-16) and lxcmyf (2026-04-17)
covering silent default-value drift introduced by the new reference.conf.
Verified each drift against develop Args.initRocksDbSettings /
applyConfigParams runtime fallbacks.

reference.conf:
- storage.dbSettings.compactThreads: 32 -> 0 (0 = auto: max(availableProcessors, 1))
- storage.dbSettings.blocksize: 64 -> 16
- storage.dbSettings.level0FileNumCompactionTrigger: 4 -> 2
- storage.dbSettings.targetFileSizeBase: 256 -> 64
- node.trustNode: "127.0.0.1:50051" -> "" (Args bridge converts empty -> null)
- node.maxActiveNodesWithSameIp: line removed. Shipping the legacy alias in
  reference.conf caused HOCON merges to always mask user-supplied
  maxConnectionsWithSameIp via the alias-fallback branch.
- node.validContractProto.threads: 2 -> 0 (0 = auto: availableProcessors)

StorageConfig.java:
- DbSettingsConfig field defaults mirror reference.conf
- DbSettingsConfig.postProcess() expands compactThreads == 0 to
  max(availableProcessors, 1), matching develop Args.java:1609-1611

NodeConfig.java:
- ValidContractProtoConfig.threads default: 2 -> 0
- postProcess() expands validContractProto.threads == 0 to
  availableProcessors(), matching develop Args.java:743-746
- Removed unused field maxActiveNodesWithSameIp. The alias read at
  fromConfig() uses section.hasPath() directly, and removing the bean field
  lets ConfigBeanFactory stop requiring a reference.conf default for it
  (which is what caused the alias pollution to begin with).

Tests:
- StorageConfigTest.testDbSettingsDefaults asserts the new fallbacks
- StorageConfigTest: testCompactThreadsAutoExpand / testCompactThreadsExplicitPreserved
- NodeConfigTest: testValidContractProtoThreadsDefaultAutoExpands /
  testValidContractProtoThreadsExplicitPreserved
- NodeConfigTest: testTrustNodeNotDefaultedByReferenceConf
- NodeConfigTest: testMaxConnectionsWithSameIpNotOverriddenByReferenceConfAlias
- NodeConfigTest: testMaxActiveNodesWithSameIpLegacyAliasStillWorks
- NodeConfigTest: testLegacyAliasTakesPriorityOverModernKey (matches develop
  Args.java:392-399)

Author: vividctrlalt

common/src/main/java/org/tron/core/config/args/NodeConfig.java

@@ -89,7 +89,9 @@ public class NodeConfig {
   private double activeConnectFactor = 0.1;
   private double connectFactor = 0.6;
   private double disconnectNumberFactor = 0.4;
-  private int maxActiveNodesWithSameIp = 2;
+  // Legacy alias `maxActiveNodesWithSameIp` has no bean field: we only peek at it via
+  // section.hasPath() below. Keeping it field-less means reference.conf doesn't have to
+  // ship a default that would otherwise mask the modern `maxConnectionsWithSameIp` key.
 
   // ---- Sub-beans matching config's dot-notation nested structure ----
   private ListenConfig listen = new ListenConfig();
@@ -180,7 +182,7 @@ public static class ReadConfig {
   @Getter
   @Setter
   public static class ValidContractProtoConfig {
-    private int threads = 2;
+    private int threads = 0; // 0 = auto (availableProcessors)
   }
 
   @Getter
@@ -428,6 +430,11 @@ private void postProcess() {
       solidity.threads = Runtime.getRuntime().availableProcessors();
     }
 
+    // validContractProto.threads: 0 = auto-detect (matches develop Args.java:743-746)
+    if (validContractProto.threads == 0) {
+      validContractProto.threads = Runtime.getRuntime().availableProcessors();
+    }
+
     // syncFetchBatchNum: clamp to [100, 2000]
     if (syncFetchBatchNum > 2000) {
       syncFetchBatchNum = 2000;

common/src/main/java/org/tron/core/config/args/StorageConfig.java

@@ -111,14 +111,21 @@ public void setSwitch(String v) {
   @Setter
   public static class DbSettingsConfig {
     private int levelNumber = 7;
-    private int compactThreads = 32;
-    private int blocksize = 64;
+    private int compactThreads = 0; // 0 = auto: max(availableProcessors, 1)
+    private int blocksize = 16;
     private long maxBytesForLevelBase = 256;
     private double maxBytesForLevelMultiplier = 10;
-    private int level0FileNumCompactionTrigger = 4;
-    private long targetFileSizeBase = 256;
+    private int level0FileNumCompactionTrigger = 2;
+    private long targetFileSizeBase = 64;
     private int targetFileSizeMultiplier = 1;
     private int maxOpenFiles = 5000;
+
+    // Expand 0 → auto-detected processor count. Mirrors develop Args.java:1609-1611.
+    void postProcess() {
+      if (compactThreads == 0) {
+        compactThreads = Math.max(Runtime.getRuntime().availableProcessors(), 1);
+      }
+    }
   }
 
   @Getter
@@ -190,6 +197,8 @@ public static StorageConfig fromConfig(Config config) {
     sc.defaultDbOption = readDbOption(section, "default");
     sc.defaultMDbOption = readDbOption(section, "defaultM");
     sc.defaultLDbOption = readDbOption(section, "defaultL");
+
+    sc.dbSettings.postProcess();
     return sc;
   }
 

common/src/main/resources/reference.conf

@@ -95,12 +95,12 @@ storage {
   # Strongly recommend NOT modifying unless you know every item's meaning clearly.
   dbSettings = {
     levelNumber = 7
-    compactThreads = 32
-    blocksize = 64              // n * KB
+    compactThreads = 0          // 0 = auto: max(availableProcessors, 1)
+    blocksize = 16              // n * KB
     maxBytesForLevelBase = 256  // n * MB
     maxBytesForLevelMultiplier = 10
-    level0FileNumCompactionTrigger = 4
-    targetFileSizeBase = 256    // n * MB
+    level0FileNumCompactionTrigger = 2
+    targetFileSizeBase = 64     // n * MB
     targetFileSizeMultiplier = 1
     maxOpenFiles = 5000
   }
@@ -188,9 +188,10 @@ node.metrics = {
 }
 
 node {
-  # Trust node for solidity node
-  # trustNode = "ip:port"
-  trustNode = "127.0.0.1:50051"
+  # Trust node for solidity node (example: "127.0.0.1:50051").
+  # Empty string here = "not configured"; Args.java bridge converts "" → null so the
+  # runtime behavior matches develop (trustNodeAddr is null unless user sets the key).
+  trustNode = ""
 
   # Expose extension api to public or not
   walletExtensionApi = false
@@ -235,7 +236,9 @@ node {
   activeConnectFactor = 0.1
   connectFactor = 0.6
   disconnectNumberFactor = 0.4
-  maxActiveNodesWithSameIp = 2
+  # Legacy alias `maxActiveNodesWithSameIp` is still accepted from user config
+  # (see NodeConfig alias-fallback) but is intentionally NOT defaulted here —
+  # shipping it in reference.conf would always mask the modern `maxConnectionsWithSameIp`.
   channel.read.timeout = 0
   metricsEnable = false
 
@@ -357,8 +360,8 @@ node {
   zenTokenId = "000000"
   shieldedTransInPendingMaxCounts = 10
 
-  # Contract proto validation thread pool
-  validContractProto.threads = 2
+  # Contract proto validation thread pool (0 = auto: availableProcessors)
+  validContractProto.threads = 0
 
   dns {
     treeUrls = [

common/src/test/java/org/tron/core/config/args/NodeConfigTest.java

@@ -225,4 +225,61 @@ public void testMaxFastForwardNumBoundaryValues() {
     assertEquals(4, NodeConfig.fromConfig(
         withRef("node { maxFastForwardNum = 4 }")).getMaxFastForwardNum());
   }
+
+  // ----- validContractProto.threads: 0 = auto (availableProcessors) -----
+
+  @Test
+  public void testValidContractProtoThreadsDefaultAutoExpands() {
+    // Default in reference.conf is 0; postProcess must expand to availableProcessors.
+    // Matches develop Args.java:743-746 runtime fallback.
+    NodeConfig nc = NodeConfig.fromConfig(withRef());
+    assertEquals(Runtime.getRuntime().availableProcessors(),
+        nc.getValidContractProtoThreads());
+  }
+
+  @Test
+  public void testValidContractProtoThreadsExplicitPreserved() {
+    NodeConfig nc = NodeConfig.fromConfig(
+        withRef("node { validContractProto { threads = 3 } }"));
+    assertEquals(3, nc.getValidContractProtoThreads());
+  }
+
+  // ----- trustNode: empty reference.conf default means trustNode stays unset -----
+
+  @Test
+  public void testTrustNodeNotDefaultedByReferenceConf() {
+    // reference.conf intentionally omits `node.trustNode` so that empty configs
+    // preserve develop's behavior (trustNodeAddr stays null in the Args bridge).
+    NodeConfig nc = NodeConfig.fromConfig(withRef());
+    assertTrue(nc.getTrustNode() == null || nc.getTrustNode().isEmpty());
+  }
+
+  // ----- maxConnectionsWithSameIp alias: reference.conf must not poison merge -----
+
+  @Test
+  public void testMaxConnectionsWithSameIpNotOverriddenByReferenceConfAlias() {
+    // reference.conf must NOT ship `maxActiveNodesWithSameIp`, otherwise the alias-
+    // fallback branch would silently clobber the user's modern key. Regression guard
+    // for review #2 (317787106, 2026-04-16).
+    NodeConfig nc = NodeConfig.fromConfig(
+        withRef("node { maxConnectionsWithSameIp = 10 }"));
+    assertEquals(10, nc.getMaxConnectionsWithSameIp());
+  }
+
+  @Test
+  public void testMaxActiveNodesWithSameIpLegacyAliasStillWorks() {
+    // Back-compat: users who still write the legacy key in their config.conf
+    // must get their value routed to maxConnectionsWithSameIp.
+    NodeConfig nc = NodeConfig.fromConfig(
+        withRef("node { maxActiveNodesWithSameIp = 5 }"));
+    assertEquals(5, nc.getMaxConnectionsWithSameIp());
+  }
+
+  @Test
+  public void testLegacyAliasTakesPriorityOverModernKey() {
+    // Matches develop Args.java:392-399: if the legacy key is present, it wins.
+    NodeConfig nc = NodeConfig.fromConfig(
+        withRef("node { maxActiveNodesWithSameIp = 5, maxConnectionsWithSameIp = 10 }"));
+    assertEquals(5, nc.getMaxConnectionsWithSameIp());
+  }
 }

common/src/test/java/org/tron/core/config/args/StorageConfigTest.java

@@ -59,20 +59,42 @@ public void testCheckpointDefaults() {
 
   @Test
   public void testDbSettingsDefaults() {
+    // These defaults must match develop's Args.initRocksDbSettings() fallbacks so that
+    // nodes with minimal configs retain the same RocksDB tuning. See
+    // docs/plans/2026-04-21-001-fix-reference-conf-default-drift.md.
     Config empty = withRef();
     StorageConfig sc = StorageConfig.fromConfig(empty);
     StorageConfig.DbSettingsConfig ds = sc.getDbSettings();
     assertEquals(7, ds.getLevelNumber());
-    assertEquals(32, ds.getCompactThreads());
-    assertEquals(64, ds.getBlocksize());
+    // compactThreads default is 0 in reference.conf, auto-expanded by postProcess()
+    assertEquals(Math.max(Runtime.getRuntime().availableProcessors(), 1),
+        ds.getCompactThreads());
+    assertEquals(16, ds.getBlocksize());
     assertEquals(256, ds.getMaxBytesForLevelBase());
     assertEquals(10, ds.getMaxBytesForLevelMultiplier(), 0.01);
-    assertEquals(4, ds.getLevel0FileNumCompactionTrigger());
-    assertEquals(256, ds.getTargetFileSizeBase());
+    assertEquals(2, ds.getLevel0FileNumCompactionTrigger());
+    assertEquals(64, ds.getTargetFileSizeBase());
     assertEquals(1, ds.getTargetFileSizeMultiplier());
     assertEquals(5000, ds.getMaxOpenFiles());
   }
 
+  @Test
+  public void testCompactThreadsAutoExpand() {
+    // compactThreads = 0 must be auto-expanded to availableProcessors (min 1)
+    Config config = withRef("storage { dbSettings { compactThreads = 0 } }");
+    StorageConfig sc = StorageConfig.fromConfig(config);
+    assertEquals(Math.max(Runtime.getRuntime().availableProcessors(), 1),
+        sc.getDbSettings().getCompactThreads());
+  }
+
+  @Test
+  public void testCompactThreadsExplicitPreserved() {
+    // Non-zero compactThreads must be passed through untouched
+    Config config = withRef("storage { dbSettings { compactThreads = 7 } }");
+    StorageConfig sc = StorageConfig.fromConfig(config);
+    assertEquals(7, sc.getDbSettings().getCompactThreads());
+  }
+
   @Test
   public void testBalanceHistoryLookup() {
     Config config = withRef(