Initial commit: Xingrin v1.0.0

backend/apps/common/management/commands/db_monitor.py

@@ -0,0 +1,164 @@
+"""
+简化的数据库性能监控命令
+
+专注于可能导致查询延迟的关键指标
+"""
+
+import time
+from django.core.management.base import BaseCommand
+from django.db import connections
+
+
+class Command(BaseCommand):
+    """简化的数据库性能监控"""
+    
+    help = '监控数据库性能关键指标'
+    
+    def add_arguments(self, parser):
+        parser.add_argument(
+            '--interval',
+            type=int,
+            default=5,
+            help='监控间隔（秒，默认: 5）',
+        )
+        parser.add_argument(
+            '--count',
+            type=int,
+            default=3,
+            help='监控次数（默认: 3）',
+        )
+    
+    def handle(self, *args, **options):
+        interval = options['interval']
+        count = options['count']
+        
+        self.stdout.write("🔍 数据库性能监控开始...")
+        
+        for i in range(count):
+            if i > 0:
+                time.sleep(interval)
+            
+            self.stdout.write(f"\n=== 第 {i+1} 次监控 ===")
+            self.monitor_key_metrics()
+    
+    def monitor_key_metrics(self):
+        """监控关键性能指标"""
+        db_connection = connections['default']
+        
+        try:
+            with db_connection.cursor() as cursor:
+                # 1. 连接和活动状态
+                cursor.execute("""
+                    SELECT 
+                        count(*) as total_connections,
+                        count(*) FILTER (WHERE state = 'active') as active,
+                        count(*) FILTER (WHERE state = 'idle') as idle,
+                        count(*) FILTER (WHERE state = 'idle in transaction') as idle_in_trans,
+                        count(*) FILTER (WHERE wait_event_type IS NOT NULL) as waiting
+                    FROM pg_stat_activity;
+                """)
+                conn_stats = cursor.fetchone()
+                self.stdout.write(f"连接: 总计{conn_stats[0]} | 活跃{conn_stats[1]} | 空闲{conn_stats[2]} | 事务中{conn_stats[3]} | 等待{conn_stats[4]}")
+                
+                # 2. 锁等待情况
+                cursor.execute("""
+                    SELECT 
+                        count(*) as total_locks,
+                        count(*) FILTER (WHERE NOT granted) as waiting_locks
+                    FROM pg_locks;
+                """)
+                lock_stats = cursor.fetchone()
+                if lock_stats[1] > 0:
+                    self.stdout.write(self.style.WARNING(f"🔒 锁: 总计{lock_stats[0]} | 等待{lock_stats[1]}"))
+                else:
+                    self.stdout.write(f"🔒 锁: 总计{lock_stats[0]} | 等待{lock_stats[1]}")
+                
+                # 3. 长时间运行的查询
+                cursor.execute("""
+                    SELECT 
+                        pid,
+                        application_name,
+                        now() - query_start as duration,
+                        state,
+                        left(query, 60) as query_preview
+                    FROM pg_stat_activity 
+                    WHERE state = 'active' 
+                    AND query_start < now() - interval '1 second'
+                    AND query NOT LIKE '%pg_stat_activity%'
+                    ORDER BY query_start;
+                """)
+                long_queries = cursor.fetchall()
+                if long_queries:
+                    self.stdout.write(self.style.WARNING(f"⏱️  长查询 ({len(long_queries)} 个):"))
+                    for query in long_queries:
+                        self.stdout.write(f"   PID {query[0]} ({query[1]}): {query[2]} - {query[4]}...")
+                else:
+                    self.stdout.write("⏱️  长查询: 无")
+                
+                # 4. 缓存命中率
+                cursor.execute("""
+                    SELECT 
+                        sum(heap_blks_hit) as cache_hits,
+                        sum(heap_blks_read) as disk_reads,
+                        CASE 
+                            WHEN sum(heap_blks_hit) + sum(heap_blks_read) = 0 THEN 0
+                            ELSE round(sum(heap_blks_hit) * 100.0 / (sum(heap_blks_hit) + sum(heap_blks_read)), 2)
+                        END as hit_ratio
+                    FROM pg_statio_user_tables;
+                """)
+                cache_stats = cursor.fetchone()
+                if cache_stats[0] or cache_stats[1]:
+                    hit_ratio = cache_stats[2] or 0
+                    if hit_ratio < 95:
+                        self.stdout.write(self.style.WARNING(f"💾 缓存命中率: {hit_ratio}% (缓存:{cache_stats[0]}, 磁盘:{cache_stats[1]})"))
+                    else:
+                        self.stdout.write(f"💾 缓存命中率: {hit_ratio}% (缓存:{cache_stats[0]}, 磁盘:{cache_stats[1]})")
+                else:
+                    self.stdout.write("💾 缓存: 暂无统计数据")
+                
+                # 5. 检查点活动（尝试获取，如果失败则跳过）
+                try:
+                    cursor.execute("SELECT * FROM pg_stat_bgwriter LIMIT 1;")
+                    bgwriter_cols = [desc[0] for desc in cursor.description]
+                    
+                    if 'checkpoints_timed' in bgwriter_cols:
+                        cursor.execute("""
+                            SELECT 
+                                checkpoints_timed,
+                                checkpoints_req,
+                                checkpoint_write_time,
+                                checkpoint_sync_time
+                            FROM pg_stat_bgwriter;
+                        """)
+                        bgwriter = cursor.fetchone()
+                        total_checkpoints = bgwriter[0] + bgwriter[1]
+                        if bgwriter[2] > 10000 or bgwriter[3] > 5000:
+                            self.stdout.write(self.style.WARNING(f"📝 检查点: 总计{total_checkpoints} | 写入{bgwriter[2]}ms | 同步{bgwriter[3]}ms"))
+                        else:
+                            self.stdout.write(f"📝 检查点: 总计{total_checkpoints} | 写入{bgwriter[2]}ms | 同步{bgwriter[3]}ms")
+                    else:
+                        self.stdout.write("📝 检查点: 统计不可用")
+                except Exception:
+                    self.stdout.write("📝 检查点: 统计不可用")
+                
+                # 6. 数据库大小变化
+                cursor.execute("SELECT pg_database_size(current_database());")
+                db_size = cursor.fetchone()[0]
+                db_size_mb = round(db_size / 1024 / 1024, 2)
+                self.stdout.write(f"💿 数据库大小: {db_size_mb} MB")
+                
+                # 7. 测试查询延迟
+                start_time = time.time()
+                cursor.execute("SELECT 1")
+                cursor.fetchone()
+                query_latency = (time.time() - start_time) * 1000
+                
+                if query_latency > 500:
+                    self.stdout.write(self.style.ERROR(f"⚡ 查询延迟: {query_latency:.2f}ms (高)"))
+                elif query_latency > 200:
+                    self.stdout.write(self.style.WARNING(f"⚡ 查询延迟: {query_latency:.2f}ms (中)"))
+                else:
+                    self.stdout.write(f"⚡ 查询延迟: {query_latency:.2f}ms (正常)")
+                
+        except Exception as e:
+            self.stdout.write(self.style.ERROR(f"监控失败: {e}"))