[Enhancement](pyudf) Support MemTracker in PythonUdf

be/src/udf/python/python_server.cpp

@@ -26,6 +26,7 @@
 
 #include <boost/asio.hpp>
 #include <boost/process.hpp>
+#include <fstream>
 
 #include "common/config.h"
 #include "udf/python/python_udaf_client.h"
@@ -110,6 +111,7 @@ Status PythonServerManager::ensure_pool_initialized(const PythonVersion& version
 
     _initialized_versions.insert(version);
     _start_health_check_thread();
+    _start_memory_monitor_thread();
 
     return Status::OK();
 }
@@ -252,15 +254,21 @@ void PythonServerManager::_start_health_check_thread() {
 }
 
 void PythonServerManager::shutdown() {
-    // Signal health check thread to stop
+    // Signal health check thread and memory monitor thread to stop
     _shutdown_flag.store(true, std::memory_order_release);
     _health_check_cv.notify_one();
+    _memory_monitor_cv.notify_one();
 
     if (_health_check_thread && _health_check_thread->joinable()) {
         _health_check_thread->join();
         _health_check_thread.reset();
     }
 
+    if (_memory_monitor_thread && _memory_monitor_thread->joinable()) {
+        _memory_monitor_thread->join();
+        _memory_monitor_thread.reset();
+    }
+
     // Shutdown all processes
     std::lock_guard<std::mutex> lock(_pools_mutex);
     for (auto& [version, pool] : _process_pools) {
@@ -273,6 +281,77 @@ void PythonServerManager::shutdown() {
     _process_pools.clear();
 }
 
+void PythonServerManager::_start_memory_monitor_thread() {
+    if (_memory_monitor_thread) return;
+
+    _memory_monitor_thread = std::make_unique<std::thread>([this]() {
+        while (!_shutdown_flag.load(std::memory_order_acquire)) {
+            // Wait for interval or shutdown signal
+            {
+                std::unique_lock<std::mutex> lock(_memory_monitor_mutex);
+                _memory_monitor_cv.wait_for(lock, std::chrono::seconds(15), [this]() {
+                    return _shutdown_flag.load(std::memory_order_acquire);
+                });
+            }
+
+            if (_shutdown_flag.load(std::memory_order_acquire)) break;
+
+            _refresh_memory_stats();
+        }
+
+        LOG(INFO) << "Python process memory monitor thread exiting";
+    });
+}
+
+Status PythonServerManager::_read_process_memory(pid_t pid, size_t* rss_bytes, size_t* vms_bytes) {
+    // Read from /proc/{pid}/statm
+    // Format: size resident shared text lib data dt
+    std::string statm_path = fmt::format("/proc/{}/statm", pid);
+    std::ifstream statm_file(statm_path);
+
+    if (!statm_file.is_open()) {
+        return Status::InternalError("Cannot open {}", statm_path);
+    }
+
+    size_t vms_pages = 0, rss_pages = 0;
+    statm_file >> vms_pages >> rss_pages;
+
+    if (statm_file.fail()) {
+        return Status::InternalError("Failed to read {}", statm_path);
+    }
+
+    // Convert pages to bytes
+    long page_size = sysconf(_SC_PAGESIZE);
+    *rss_bytes = rss_pages * page_size;
+    *vms_bytes = vms_pages * page_size;
+
+    return Status::OK();
+}
+
+void PythonServerManager::_refresh_memory_stats() {
+    std::lock_guard<std::mutex> lock(_pools_mutex);
+
+    int64_t total_rss = 0;
+
+    for (const auto& [version, pool] : _process_pools) {
+        for (const auto& process : pool) {
+            if (!process || !process->is_alive()) continue;
+
+            size_t rss_bytes = 0, vms_bytes = 0;
+            Status s = _read_process_memory(process->get_child_pid(), &rss_bytes, &vms_bytes);
+
+            if (s.ok()) {
+                total_rss += rss_bytes;
+            } else [[unlikely]] {
+                LOG(WARNING) << "Failed to read memory info for Python process (pid="
+                             << process->get_child_pid() << "): " << s.to_string();
+            }
+        }
+    }
+    _mem_tracker.set_consumption(total_rss);
+    LOG(INFO) << _mem_tracker.log_usage();
+}
+
 // Explicit template instantiation for UDF, UDAF and UDTF clients
 template Status PythonServerManager::get_client<PythonUDFClient>(
         const PythonUDFMeta& func_meta, const PythonVersion& version,

be/src/udf/python/python_server.h

@@ -23,11 +23,11 @@
 #include <thread>
 
 #include "common/status.h"
+#include "runtime/memory/mem_tracker.h"
 #include "udf/python/python_udf_meta.h"
 #include "udf/python/python_udf_runtime.h"
 
 namespace doris {
-
 class PythonServerManager {
 public:
     PythonServerManager() = default;
@@ -59,6 +59,22 @@ class PythonServerManager {
      */
     void _start_health_check_thread();
 
+    /**
+     * Start memory monitor background thread
+     * Thread periodically reads /proc/{pid}/statm for each Python process
+     */
+    void _start_memory_monitor_thread();
+
+    /**
+     * Read memory information for a single process from /proc/{pid}/statm
+     */
+    Status _read_process_memory(pid_t pid, size_t* rss_bytes, size_t* vms_bytes);
+
+    /**
+     * Refresh memory statistics for all Python processes
+     */
+    void _refresh_memory_stats();
+
     std::unordered_map<PythonVersion, std::vector<ProcessPtr>> _process_pools;
     // Protects _process_pools access
     std::mutex _pools_mutex;
@@ -69,6 +85,12 @@ class PythonServerManager {
     std::atomic<bool> _shutdown_flag {false};
     std::condition_variable _health_check_cv;
     std::mutex _health_check_mutex;
+
+    // Memory monitoring
+    std::unique_ptr<std::thread> _memory_monitor_thread;
+    std::condition_variable _memory_monitor_cv;
+    std::mutex _memory_monitor_mutex;
+    MemTracker _mem_tracker {"PythonUDFProcesses"};
 };
 
 } // namespace doris