How to reconnect Nebula

[son2408]

I write a api for executing neblua, but after some time, it's always disconnected. How to reconnect it?
my code api

package main

import (
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"
	"strings"
	"time"

	"github.com/gorilla/mux"
	nebula "github.com/vesoft-inc/nebula-go/v3"
)

const (
	address = "10.234.0.1"
	// The default port of Nebula Graph 2.x is 9669.
	// 3699 is only for testing.
	port     = 9669
	username = "root"
	password = "oksi1"
)

var pool *nebula.ConnectionPool

var session *nebula.Session

func init() {
	hostAddress := nebula.HostAddress{Host: address, Port: port}
	hostList := []nebula.HostAddress{hostAddress}
	poolConfig := nebula.GetDefaultConf()
	var err error
	pool, err = nebula.NewConnectionPool(hostList, poolConfig, nebula.DefaultLogger{})
	if err != nil {
		log.Fatal(fmt.Sprintf("Fail to initialize the connection pool, host: %s, port: %d, %s", address, port, err.Error()))
	}
	session, err = pool.GetSession(username, password)
	if err != nil {
		log.Fatal(fmt.Sprintf("Fail to create a new session from connection pool, username: %s, password: %s, %s",
			username, password, err.Error()))
	}
}

func main() {
	router := mux.NewRouter()
	router.HandleFunc("/data", GetData).Methods("POST")
	http.ListenAndServe(":8500", router)
	defer pool.Close()
	defer session.Release()
}

type JsonObj struct {
	Results []struct {
		Columns []string
		Data    []struct {
			Row  []interface{}
			Meta []interface{}
		}
	}
	Errors []struct {
		Code    int
		Message string
	}
}

// Initialize logger
var log = nebula.DefaultLogger{}

type request struct {
	Query string
}

func GetData(w http.ResponseWriter, r *http.Request) {
	var request request
	_ = json.NewDecoder(r.Body).Decode(&request)
	var err error
	if err != nil {
		log.Fatal(fmt.Sprintf("Fail to create a new session from connection pool, username: %s, password: %s, %s",
			username, password, err.Error()))
	}
	jsonResult, err := session.ExecuteJson(request.Query)

	if err != nil {
		log.Fatal(fmt.Sprintf("fail to get the result in json format, %s", err.Error()))
	}
	var jsonObj JsonObj
	json.Unmarshal(jsonResult, &jsonObj)
	json.NewEncoder(w).Encode(jsonObj)
}

[wey-gu]

cc @Aiee

ps. I recommend using session pool instead of the connection pool.

https://github.com/vesoft-inc/nebula-go/blob/master/session_pool_example/session_pool_example.go

[son2408]

cc @Aiee

ps. I recommend using session pool instead of the connection pool.

https://github.com/vesoft-inc/nebula-go/blob/master/session_pool_example/session_pool_example.go

ok @wey-gu, I will try it

[son2408]

cc @Aiee
ps. I recommend using session pool instead of the connection pool.
https://github.com/vesoft-inc/nebula-go/blob/master/session_pool_example/session_pool_example.go

ok @wey-gu, I will try it

@wey-gu Session Pool can't execute json :(
[FATAL] fail to get the result in json format, not implemented

[son2408]

Your code does not implement

[Aiee]

Hi,
What's the error you received? Is the graph service still running when you encounter the problem?

[QingZ11]

@son2408 Hi, I have noticed that the issue you created hasn’t been updated for nearly a month, is this issue been resolved? If not resolved, can you provide some more information? If solved, can you close this issue?

Thanks a lot for your contribution anyway 😊