Go: introduce clickhouse (#16996)

### Summary

Introduce Clickhouse for data statistics.

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

internal/admin/service.go

@@ -27,6 +27,7 @@ import (
 	"ragflow/internal/common"
 	"ragflow/internal/dao"
 	"ragflow/internal/engine"
+	"ragflow/internal/engine/clickhouse"
 	"ragflow/internal/engine/elasticsearch"
 	"ragflow/internal/engine/redis"
 	"ragflow/internal/entity"
@@ -970,6 +971,14 @@ func (s *Service) ListServices() ([]map[string]interface{}, error) {
 				configDict["status"] = "timeout"
 			}
 			if serviceDetail != nil {
+				// delete element of configDict
+				delete(configDict, "extra")
+				delete(configDict, "database")
+				delete(configDict, "password")
+				delete(configDict, "sample_ratio")
+				delete(configDict, "secure")
+				delete(configDict, "stdout")
+				delete(configDict, "user")
 				results = append(results, configDict)
 			}
 		}
@@ -1042,6 +1051,10 @@ func (s *Service) GetServiceDetails(configDict map[string]interface{}) (map[stri
 		return s.checkRAGFlowServerAlive(name)
 	case "file_store":
 		return s.checkMinioAlive(name)
+	case "olap":
+		return s.checkOlapAlive(name)
+	case "tracing":
+		return s.checkTracingAlive(name)
 	default:
 		return nil, nil
 	}
@@ -1368,6 +1381,41 @@ func (s *Service) checkNatsAlive(name string, ip string, port int) (map[string]i
 	}, nil
 }
 
+// checkTracingAlive checks if tracing is alive
+func (s *Service) checkTracingAlive(name string) (map[string]interface{}, error) {
+	return map[string]interface{}{
+		"service_name": name,
+		"status":       "unknown",
+		"message":      "Tracing health check not implemented",
+	}, nil
+}
+
+// checkOlapAlive checks if ClickHouse is alive
+func (s *Service) checkOlapAlive(name string) (map[string]interface{}, error) {
+	clickhouseDriver := clickhouse.GetDriver()
+	if clickhouseDriver == nil {
+		return map[string]interface{}{
+			"service_name": name,
+			"status":       "ClickHouse engine not initialized",
+		}, nil
+	}
+
+	status, err := clickhouseDriver.Status()
+	if err != nil {
+		return map[string]interface{}{
+			"service_name": name,
+			"status":       "timeout",
+			"message":      fmt.Sprintf("error: %s", err.Error()),
+		}, nil
+	}
+
+	return map[string]interface{}{
+		"service_name": name,
+		"status":       "alive",
+		"message":      status,
+	}, nil
+}
+
 // ShutdownService shutdown service
 func (s *Service) ShutdownService(serviceID string) (map[string]interface{}, error) {
 	// TODO: Implement with proper service manager

internal/engine/clickhouse/clickhouse.go

@@ -0,0 +1,102 @@
+//
+//  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+//
+
+package clickhouse
+
+import (
+	//"context"
+	//"crypto/tls"
+	//"fmt"
+	//"log"
+
+	"context"
+	"fmt"
+	"ragflow/internal/server"
+	"sync"
+	"time"
+
+	"github.com/ClickHouse/clickhouse-go/v2"
+	"github.com/ClickHouse/clickhouse-go/v2/lib/driver"
+)
+
+var (
+	globalDriver *Driver
+	once         sync.Once
+)
+
+// GetDriver gets global ClickHouse client instance
+func GetDriver() *Driver {
+	return globalDriver
+}
+
+type Driver struct {
+	conn   driver.Conn
+	config *clickhouse.Options
+}
+
+func Init(config *server.ClickhouseConfig, ctx context.Context) error {
+	var err error
+	once.Do(func() {
+		address := fmt.Sprintf("%s:%d", config.Host, config.Port)
+
+		globalDriver = &Driver{}
+		globalDriver.config = &clickhouse.Options{
+			Addr: []string{address},
+			Auth: clickhouse.Auth{
+				Database: config.Database,
+				Username: config.User,
+				Password: config.Password,
+			},
+			DialTimeout:     5 * time.Second,
+			MaxOpenConns:    10,
+			MaxIdleConns:    5,
+			ConnMaxLifetime: time.Hour,
+		}
+
+		globalDriver.conn, err = clickhouse.Open(globalDriver.config)
+		if err != nil {
+			return
+		}
+
+		if err = globalDriver.conn.Ping(ctx); err != nil {
+			return
+		}
+	})
+	return err
+}
+
+func (d *Driver) Ping(ctx context.Context) error {
+	return d.conn.Ping(ctx)
+}
+
+func (d *Driver) Status() (map[string]interface{}, error) {
+	stats := d.conn.Stats()
+	version, err := d.conn.ServerVersion()
+	if err != nil {
+		return nil, fmt.Errorf("failed to get server version: %w", err)
+	}
+	return map[string]interface{}{
+		"max_open_conns": stats.MaxOpenConns,
+		"max_idle_conns": stats.MaxIdleConns,
+		"open":           stats.Open,
+		"idle":           stats.Idle,
+		"server_version": version.String(),
+	}, nil
+}
+
+func Close() error {
+	return globalDriver.conn.Close()
+}

internal/server/config.go

@@ -54,6 +54,7 @@ type Config struct {
 	TaskExecutor     TaskExecutorConfig     `mapstructure:"task_executor"`
 	FileSyncer       FileSyncerConfig       `mapstructure:"file_syncer"`
 	OTel             OtelConfig             `mapstructure:"otel"`
+	Clickhouse       ClickhouseConfig       `mapstructure:"clickhouse"`
 }
 
 // AdminConfig admin server configuration
@@ -90,7 +91,14 @@ type OtelConfig struct {
 	Stdout      bool    `mapstructure:"stdout"`
 }
 
-// UserDefaultLLMConfig user default LLM configuration
+type ClickhouseConfig struct {
+	Host     string `mapstructure:"host"`
+	Port     int    `mapstructure:"port"`
+	User     string `mapstructure:"user"`
+	Password string `mapstructure:"password"`
+	Database string `mapstructure:"database"`
+}
+
 type UserDefaultLLMConfig struct {
 	DefaultModels DefaultModelsConfig `mapstructure:"default_models"`
 }
@@ -427,13 +435,17 @@ func Init(configPath string) error {
 			}
 			delete(configDict, "message_queue_type")
 		case "nats":
-			host := getString(configDict, "host")
-			port := getInt(configDict, "port")
 			configDict["id"] = id
 			configDict["name"] = "nats"
-			configDict["host"] = host
-			configDict["port"] = port
 			configDict["service_type"] = "message_queue"
+		case "otel":
+			configDict["id"] = id
+			configDict["name"] = "jaeger"
+			configDict["service_type"] = "tracing"
+		case "clickhouse":
+			configDict["id"] = id
+			configDict["name"] = "clickhouse"
+			configDict["service_type"] = "olap"
 		case "admin":
 			// Skip admin section
 			continue