From 57579c8c5a8e1403b7faef3526591b7963fd7875 Mon Sep 17 00:00:00 2001
From: ffccites <99155080+PDGGK@users.noreply.github.com>
Date: Mon, 23 Feb 2026 01:51:38 +0800
Subject: [PATCH] Fix Process resource leak in system metrics collection

Add process.waitFor() and process.destroyForcibly() in finally block
to prevent zombie processes when collecting system memory and network
metrics via Runtime.exec(). Guard destroyForcibly() with isAlive()
check to avoid killing already-exited processes. Also handle
InterruptedException and NumberFormatException properly.

Affected files:
- SystemMetrics: memory info collection via 'free' command
- LinuxNetMetricManager: socket count collection via 'ls /proc/fd'

Signed-off-by: ffccites <99155080+PDGGK@users.noreply.github.com>
---
 .../metricsets/net/LinuxNetMetricManager.java       | 13 ++++++++++++-
 .../metrics/metricsets/system/SystemMetrics.java    | 11 ++++++++++-
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/iotdb-core/metrics/interface/src/main/java/org/apache/iotdb/metrics/metricsets/net/LinuxNetMetricManager.java b/iotdb-core/metrics/interface/src/main/java/org/apache/iotdb/metrics/metricsets/net/LinuxNetMetricManager.java
index 2c81bc0efc03..19cc1608a1e4 100644
--- a/iotdb-core/metrics/interface/src/main/java/org/apache/iotdb/metrics/metricsets/net/LinuxNetMetricManager.java
+++ b/iotdb-core/metrics/interface/src/main/java/org/apache/iotdb/metrics/metricsets/net/LinuxNetMetricManager.java
@@ -218,8 +218,9 @@ private void updateNetStatus() {
 
     if (MetricLevel.higherOrEqual(MetricLevel.NORMAL, METRIC_CONFIG.getMetricLevel())) {
       // update socket num
+      Process process = null;
       try {
-        Process process = Runtime.getRuntime().exec(this.getConnectNumCmd);
+        process = Runtime.getRuntime().exec(this.getConnectNumCmd);
         StringBuilder result = new StringBuilder();
         try (BufferedReader input =
             new BufferedReader(new InputStreamReader(process.getInputStream()))) {
@@ -228,9 +229,19 @@ private void updateNetStatus() {
             result.append(line);
           }
         }
+        process.waitFor();
         this.connectionNum = Integer.parseInt(result.toString().trim());
       } catch (IOException e) {
         LOGGER.error("Failed to get socket num", e);
+      } catch (InterruptedException e) {
+        LOGGER.error("Interrupted while waiting for socket num command", e);
+        Thread.currentThread().interrupt();
+      } catch (NumberFormatException e) {
+        LOGGER.error("Failed to parse socket num from command output: '{}'", e.getMessage());
+      } finally {
+        if (process != null && process.isAlive()) {
+          process.destroyForcibly();
+        }
       }
     }
   }
diff --git a/iotdb-core/metrics/interface/src/main/java/org/apache/iotdb/metrics/metricsets/system/SystemMetrics.java b/iotdb-core/metrics/interface/src/main/java/org/apache/iotdb/metrics/metricsets/system/SystemMetrics.java
index 1cacf2bf6f5f..e14d8910791a 100644
--- a/iotdb-core/metrics/interface/src/main/java/org/apache/iotdb/metrics/metricsets/system/SystemMetrics.java
+++ b/iotdb-core/metrics/interface/src/main/java/org/apache/iotdb/metrics/metricsets/system/SystemMetrics.java
@@ -217,8 +217,9 @@ private void updateLinuxSystemMemInfo() {
     long time = System.currentTimeMillis();
     if (time - lastUpdateTime > MetricConstant.UPDATE_INTERVAL) {
       lastUpdateTime = time;
+      Process process = null;
       try {
-        Process process = runtime.exec(getSystemMemoryCommand);
+        process = runtime.exec(getSystemMemoryCommand);
         StringBuilder result = new StringBuilder();
         try (BufferedReader input =
             new BufferedReader(new InputStreamReader(process.getInputStream()))) {
@@ -227,6 +228,7 @@ private void updateLinuxSystemMemInfo() {
             result.append(line).append("\n");
           }
         }
+        process.waitFor();
         String[] lines = result.toString().trim().split("\n");
         // if failed to get result
         if (lines.length >= 2) {
@@ -240,6 +242,13 @@ private void updateLinuxSystemMemInfo() {
         }
       } catch (IOException e) {
         logger.debug("Failed to get memory, because ", e);
+      } catch (InterruptedException e) {
+        logger.debug("Interrupted while waiting for memory command", e);
+        Thread.currentThread().interrupt();
+      } finally {
+        if (process != null && process.isAlive()) {
+          process.destroyForcibly();
+        }
       }
     }
   }