⚡️ perf(kingbase): 消除 SQL 查询周期性探活延迟

- 成功 SQL 往返后刷新缓存连接健康时间
- 避免活跃连接跨过旧时间边界时同步重复 Ping
- 保留空闲连接探活、失效清理与重建机制
- 新增 Kingbase 查询健康时间回归测试

internal/app/app.go

@@ -660,6 +660,25 @@ func (a *App) databaseConnectionReturnError(cacheKey string, inst db.Database) e
 	return nil
 }
 
+func (a *App) markCachedDatabaseHealthy(inst db.Database, healthyAt time.Time) {
+	if a == nil || inst == nil {
+		return
+	}
+	if healthyAt.IsZero() {
+		healthyAt = time.Now()
+	}
+
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	for key, entry := range a.dbCache {
+		if entry.inst != inst || !healthyAt.After(entry.lastPing) {
+			continue
+		}
+		entry.lastPing = healthyAt
+		a.dbCache[key] = entry
+	}
+}
+
 func (a *App) cancelDatabaseConnectFlightsLocked(match func(*databaseConnectFlight) bool, cancelErr error, excludedFlightID uint64) []string {
 	groupKeys := make([]string, 0)
 	for _, flight := range a.dbConnectFlights {

internal/app/methods_db.go

@@ -1144,6 +1144,7 @@ func (a *App) dbQueryMulti(
 	// 慢 SQL 埋点：成功执行后记录（低于阈值 500ms 自动跳过）。
 	// 用 named return + defer 覆盖所有 return path，避免遗漏。
 	var queryExecutionDuration time.Duration
+	queryExecuted := false
 	defer func() {
 		if !result.Success {
 			return
@@ -1153,6 +1154,7 @@ func (a *App) dbQueryMulti(
 	}()
 	measureQueryExecution := func(run func()) {
 		startedAt := time.Now()
+		queryExecuted = true
 		run()
 		queryExecutionDuration += time.Since(startedAt)
 	}
@@ -1190,6 +1192,12 @@ func (a *App) dbQueryMulti(
 		logger.Error(err, "DBQueryMulti 获取连接失败：%s", formatConnSummary(runConfig))
 		return connection.QueryResult{Success: false, Message: err.Error(), QueryID: queryID}
 	}
+	defer func() {
+		// A successful SQL round trip is at least as strong a health signal as Ping.
+		if result.Success && queryExecuted {
+			a.markCachedDatabaseHealthy(dbInst, time.Now())
+		}
+	}()
 
 	ctx, cancel := newQueryExecutionContext(runConfig)
 	defer cancel()
@@ -1298,6 +1306,7 @@ func (a *App) dbQueryMulti(
 				logger.Error(retryErr, "DBQueryMulti 重建连接失败：%s SQL片段=%q", formatConnSummary(runConfig), sqlSnippet(query))
 				return connection.QueryResult{Success: false, Message: retryErr.Error(), QueryID: queryID}
 			}
+			dbInst = retryInst
 			results, resultMessages, err = runMultiQuery(retryInst)
 		}
 	}
@@ -1411,6 +1420,7 @@ func (a *App) dbQueryMulti(
 							logger.Error(retryErr, "DBQueryMulti 批量写重建连接失败：%s", formatConnSummary(runConfig))
 							return connection.QueryResult{Success: false, Message: retryErr.Error(), QueryID: queryID}
 						}
+						dbInst = retryInst
 						if retryBatcher, ok2 := retryInst.(db.BatchWriteExecer); ok2 {
 							measureQueryExecution(func() {
 								affected, batchErr = retryBatcher.ExecBatchContext(ctx, query)

internal/app/methods_db_multi_test.go

@@ -17,6 +17,7 @@ import (
 type fakeBatchWriteDB struct {
 	batchCalls   int
 	execCalls    int
+	pingCalls    int
 	execQueries  []string
 	lastQuery    string
 	lastCtx      context.Context
@@ -114,6 +115,7 @@ func (f *fakeBatchWriteDB) Close() error {
 }
 
 func (f *fakeBatchWriteDB) Ping() error {
+	f.pingCalls++
 	return nil
 }
 
@@ -2318,6 +2320,49 @@ func TestDBQueryMultiPrefersPlainQueryForKingbaseReadResults(t *testing.T) {
 	}
 }
 
+func TestDBQueryMultiSuccessfulKingbaseQueryRefreshesCachedHealthTimestamp(t *testing.T) {
+	installFakeOptionalDriverRuntime(t)
+
+	query := "SELECT * FROM ldf_server.andon_dash_events LIMIT 101 OFFSET 0"
+	fakeDB := &fakeBatchWriteDB{
+		queryMap: map[string][]map[string]interface{}{
+			query: {
+				{"id": 1},
+			},
+		},
+		fieldMap: map[string][]string{
+			query: {"id"},
+		},
+		queryErr: map[string]error{},
+	}
+	app := NewAppWithSecretStore(secretstore.NewUnavailableStore("test"))
+	config := connection.ConnectionConfig{
+		Type:     "kingbase",
+		Host:     "127.0.0.1",
+		Port:     54321,
+		User:     "system",
+		Database: "ldf_server_dbs_dev",
+	}
+	key := getCacheKey(config)
+	previousHealthyAt := time.Now().Add(-10 * time.Second)
+	app.dbCache[key] = cachedDatabase{
+		inst:     fakeDB,
+		lastPing: previousHealthyAt,
+		config:   normalizeCacheKeyConfig(config),
+	}
+
+	result := app.DBQueryMulti(config, config.Database, query, "kingbase-refresh-cache-health-test")
+	if !result.Success {
+		t.Fatalf("expected DBQueryMulti success, got failure: %s", result.Message)
+	}
+	if fakeDB.pingCalls != 0 {
+		t.Fatalf("expected a recently healthy cached connection to skip foreground Ping, got %d calls", fakeDB.pingCalls)
+	}
+	if got := app.dbCache[key].lastPing; !got.After(previousHealthyAt) {
+		t.Fatalf("expected successful query to refresh cached health timestamp, before=%s after=%s", previousHealthyAt, got)
+	}
+}
+
 func TestDBQueryMultiPrefersPlainQueryForDamengReadResults(t *testing.T) {
 	originalNewDatabaseFunc := newDatabaseFunc
 	t.Cleanup(func() {