From 29d122f7ef225aec7b138ac2de33124852be6556 Mon Sep 17 00:00:00 2001
From: Caideyipi <87789683+Caideyipi@users.noreply.github.com>
Date: Mon, 8 Sep 2025 14:45:08 +0800
Subject: [PATCH] Changed the default MQTT handler size to 1/2 number of
 processors & Fixed some default parameters when core number is 1 (#16363)

* fix

* fix
---
 .../src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java   | 2 +-
 .../main/java/org/apache/iotdb/db/conf/IoTDBDescriptor.java   | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java
index 3d2b6b6fa5e03..2a85be595c311 100644
--- a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java
+++ b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java
@@ -109,7 +109,7 @@ public class IoTDBConfig {
   private int mqttPort = 1883;
 
   /** The handler pool size for handing the mqtt messages. */
-  private int mqttHandlerPoolSize = 1;
+  private int mqttHandlerPoolSize = Math.max(1, Runtime.getRuntime().availableProcessors() >> 1);
 
   /** The mqtt message payload formatter. */
   private String mqttPayloadFormatter = "json";
diff --git a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/conf/IoTDBDescriptor.java b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/conf/IoTDBDescriptor.java
index c79c67a409e31..bfc47bf58e033 100644
--- a/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/conf/IoTDBDescriptor.java
+++ b/iotdb-core/datanode/src/main/java/org/apache/iotdb/db/conf/IoTDBDescriptor.java
@@ -586,7 +586,7 @@ public void loadProperties(TrimProperties properties) throws BadNodeUrlException
                 "degree_of_query_parallelism", Integer.toString(conf.getDegreeOfParallelism()))));
 
     if (conf.getDegreeOfParallelism() <= 0) {
-      conf.setDegreeOfParallelism(Runtime.getRuntime().availableProcessors() / 2);
+      conf.setDegreeOfParallelism(Math.max(1, Runtime.getRuntime().availableProcessors() / 2));
     }
 
     conf.setMergeThresholdOfExplainAnalyze(
@@ -2730,7 +2730,7 @@ private void loadCQProps(TrimProperties properties) {
                 "continuous_query_thread_num",
                 Integer.toString(conf.getContinuousQueryThreadNum()))));
     if (conf.getContinuousQueryThreadNum() <= 0) {
-      conf.setContinuousQueryThreadNum(Runtime.getRuntime().availableProcessors() / 2);
+      conf.setContinuousQueryThreadNum(Math.max(1, Runtime.getRuntime().availableProcessors() / 2));
     }
 
     conf.setContinuousQueryMinimumEveryInterval(