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golang实现连接池的方法
这篇文章将为大家详细讲解有关golang实现连接池的方法，小编觉得挺实用的，因此分享给大家做个参考，希望大家阅读完这篇文章后可以有所收获。
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Reids
安装导入
go get github.com/garyburd/redigo/redis import "github.com/garyburd/redigo/redis"
使用
连接
import "github.com/garyburd/redigo/redis"
func main() {
c, err := redis.Dial("tcp", "localhost:6379")
if err != nil {
fmt.Println("conn redis failed, err:", err)
return
}
defer c.Close()
}set & get
_, err = c.Do("Set", "name", "nick")
if err != nil {
fmt.Println(err)
return
}
r, err := redis.String(c.Do("Get", "name"))
if err != nil {
fmt.Println(err)
return
}
fmt.Println(r)mset & mget
批量设置
_, err = c.Do("MSet", "name", "nick", "age", "18")
if err != nil {
fmt.Println("MSet error: ", err)
return
}
r2, err := redis.Strings(c.Do("MGet", "name", "age"))
if err != nil {
fmt.Println("MGet error: ", err)
return
}
fmt.Println(r2)hset & hget
hash操作
_, err = c.Do("HSet", "names", "nick", "suoning")
if err != nil {
fmt.Println("hset error: ", err)
return
}
r, err = redis.String(c.Do("HGet", "names", "nick"))
if err != nil {
fmt.Println("hget error: ", err)
return
}
fmt.Println(r)expire
设置过期时间
_, err = c.Do("expire", "names", 5)
if err != nil {
fmt.Println("expire error: ", err)
return
}lpush & lpop & llen
队列
// 队列
_, err = c.Do("lpush", "Queue", "nick", "dawn", 9)
if err != nil {
fmt.Println("lpush error: ", err)
return
}
for {
r, err = redis.String(c.Do("lpop", "Queue"))
if err != nil {
fmt.Println("lpop error: ", err)
break
}
fmt.Println(r)
}
r3, err := redis.Int(c.Do("llen", "Queue"))
if err != nil {
fmt.Println("llen error: ", err)
return
}连接池
各参数的解释如下：
MaxIdle：最大的空闲连接数，表示即使没有redis连接时依然可以保持N个空闲的连接，而不被清除，随时处于待命状态。
MaxActive：最大的激活连接数，表示同时最多有N个连接
IdleTimeout：最大的空闲连接等待时间，超过此时间后，空闲连接将被关闭
pool := &redis.Pool{
MaxIdle: 16,
MaxActive: 1024,
IdleTimeout: 300,
Dial: func() (redis.Conn, error) {
return redis.Dial("tcp", "localhost:6379")
},
}连接池例子：
package main
import (
"fmt"
"github.com/garyburd/redigo/redis"
)
var pool *redis.Pool
func init() {
pool = &redis.Pool{
MaxIdle: 16,
MaxActive: 1024,
IdleTimeout: 300,
Dial: func() (redis.Conn, error) {
return redis.Dial("tcp", "localhost:6379")
},
}
}
func main() {
c := pool.Get()
defer c.Close()
_, err := c.Do("Set", "name", "nick")
if err != nil {
fmt.Println(err)
return
}
r, err := redis.String(c.Do("Get", "name"))
if err != nil {
fmt.Println(err)
return
}
fmt.Println(r)
}管道操作
请求/响应服务可以实现持续处理新请求，客户端可以发送多个命令到服务器而无需等待响应，最后在一次读取多个响应。
使用Send()，Flush()，Receive()方法支持管道化操作
Send向连接的输出缓冲中写入命令。
Flush将连接的输出缓冲清空并写入服务器端。
Recevie按照FIFO顺序依次读取服务器的响应。
func main() {
c, err := redis.Dial("tcp", "localhost:6379")
if err != nil {
fmt.Println("conn redis failed, err:", err)
return
}
defer c.Close()
c.Send("SET", "name1", "sss1")
c.Send("SET", "name2", "sss2")
c.Flush()
v, err := c.Receive()
fmt.Printf("v:%v,err:%v\n", v, err)
v, err = c.Receive()
fmt.Printf("v:%v,err:%v\n", v, err)
v, err = c.Receive() // 夯住，一直等待
fmt.Printf("v:%v,err:%v\n", v, err)
}MySQL
安装导入
go get "github.com/go-sql-driver/mysql"
go get "github.com/jmoiron/sqlx"
import (
_ "github.com/go-sql-driver/mysql"
"github.com/jmoiron/sqlx"
)连接
import (
_ "github.com/go-sql-driver/mysql"
"github.com/jmoiron/sqlx"
)
var Db *sqlx.DB
func init() {
database, err := sqlx.Open("mysql", "root:@tcp(127.0.0.1:3306)/test")
if err != nil {
fmt.Println("open mysql failed,", err)
return
}
Db = database
}建表
CREATE TABLE `person` ( `user_id` int(128) DEFAULT NULL, `username` varchar(255) DEFAULT NULL, `sex` varchar(16) DEFAULT NULL, `email` varchar(128) DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8
（insert）
package main
import (
"fmt"
_ "github.com/go-sql-driver/mysql"
"github.com/jmoiron/sqlx"
)
type Person struct {
UserId int `db:"user_id"`
Username string `db:"username"`
Sex string `db:"sex"`
Email string `db:"email"`
}
var Db *sqlx.DB
func init() {
database, err := sqlx.Open("mysql", "root:@tcp(127.0.0.1:3306)/test")
if err != nil {
fmt.Println("open mysql failed,", err)
return
}
Db = database
}
func main() {
r, err := Db.Exec("insert into person(username, sex, email)values(?, ?, ?)", "suoning", "man", "suoning@net263.com")
if err != nil {
fmt.Println("exec failed, ", err)
return
}
id, err := r.LastInsertId()
if err != nil {
fmt.Println("exec failed, ", err)
return
}
fmt.Println("insert succ:", id)
}（update）
package main
import (
"fmt"
_ "github.com/go-sql-driver/mysql"
"github.com/jmoiron/sqlx"
)
type Person struct {
UserId int `db:"user_id"`
Username string `db:"username"`
Sex string `db:"sex"`
Email string `db:"email"`
}
var Db *sqlx.DB
func init() {
database, err := sqlx.Open("mysql", "root:@tcp(127.0.0.1:3306)/test")
if err != nil {
fmt.Println("open mysql failed,", err)
return
}
Db = database
}
func main() {
_, err := Db.Exec("update person set user_id=? where username=?", 20170808, "suoning")
if err != nil {
fmt.Println("exec failed, ", err)
return
}
}（select）
package main
import (
"fmt"
_ "github.com/go-sql-driver/mysql"
"github.com/jmoiron/sqlx"
)
type Person struct {
UserId int `db:"user_id"`
Username string `db:"username"`
Sex string `db:"sex"`
Email string `db:"email"`
}
type Place struct {
Country string `db:"country"`
City string `db:"city"`
TelCode int `db:"telcode"`
}
var Db *sqlx.DB
func init() {
database, err := sqlx.Open("mysql", "root:@tcp(127.0.0.1:3306)/test")
if err != nil {
fmt.Println("open mysql failed,", err)
return
}
Db = database
}
func main() {
var person []Person
err := Db.Select(&person, "select user_id, username, sex, email from person where user_id=?", 1)
if err != nil {
fmt.Println("exec failed, ", err)
return
}
fmt.Println("select succ:", person)
people := []Person{}
Db.Select(&people, "SELECT * FROM person ORDER BY user_id ASC")
fmt.Println(people)
jason, john := people[0], people[1]
fmt.Printf("%#v\n%#v", jason, john)
}（delete）
package main
import (
"fmt"
_ "github.com/go-sql-driver/mysql"
"github.com/jmoiron/sqlx"
)
type Person struct {
UserId int `db:"user_id"`
Username string `db:"username"`
Sex string `db:"sex"`
Email string `db:"email"`
}
var Db *sqlx.DB
func init() {
database, err := sqlx.Open("mysql", "root:@tcp(127.0.0.1:3306)/test")
if err != nil {
fmt.Println("open mysql failed,", err)
return
}
Db = database
}
func main() {
_, err := Db.Exec("delete from person where username=? limit 1", "suoning")
if err != nil {
fmt.Println("exec failed, ", err)
return
}
fmt.Println("delete succ")
}事务
package main
import (
"github.com/astaxie/beego/logs"
_ "github.com/go-sql-driver/mysql"
"github.com/jmoiron/sqlx"
)
var Db *sqlx.DB
func init() {
database, err := sqlx.Open("mysql", "root:@tcp(127.0.0.1:3306)/test")
if err != nil {
logs.Error("open mysql failed,", err)
return
}
Db = database
}
func main() {
conn, err := Db.Begin()
if err != nil {
logs.Warn("DB.Begin failed, err:%v", err)
return
}
defer func() {
if err != nil {
conn.Rollback()
return
}
conn.Commit()
}()
// do something
}RabbitMQ
安装
go get "github.com/streadway/amqp"
普通模式
生产者：
package main
import ( "fmt"
"log"
"os"
"strings"
"github.com/streadway/amqp"
"time")/*默认点对点模式*/func failOnError(err error, msg string) { if err != nil {
log.Fatalf("%s: %s", msg, err)
panic(fmt.Sprintf("%s: %s", msg, err))
}
}
func main() { // 连接
conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")
failOnError(err, "Failed to connect to RabbitMQ")
defer conn.Close() // 打开一个并发服务器通道来处理消息
ch, err := conn.Channel()
failOnError(err, "Failed to open a channel")
defer ch.Close() // 申明一个队列
q, err := ch.QueueDeclare( "task_queue", // name
true, // durable 持久性的,如果事前已经声明了该队列，不能重复声明
false, // delete when unused
false, // exclusive 如果是真，连接一断开，队列删除
false, // no-wait
nil, // arguments )
failOnError(err, "Failed to declare a queue")
body := bodyFrom(os.Args) // 发布
err = ch.Publish( "", // exchange 默认模式，exchange为空
q.Name, // routing key 默认模式路由到同名队列，即是task_queue
false, // mandatory
false,
amqp.Publishing{ // 持久性的发布，因为队列被声明为持久的，发布消息必须加上这个（可能不用），但消息还是可能会丢，如消息到缓存但MQ挂了来不及持久化。 DeliveryMode: amqp.Persistent,
ContentType: "text/plain",
Body: []byte(body),
})
failOnError(err, "Failed to publish a message")
log.Printf(" [x] Sent %s", body)
}
func bodyFrom(args []string) string { var s string
if (len(args) < 2) || os.Args[1] == "" {
s = fmt.Sprintf("%s-%v","hello", time.Now())
} else {
s = strings.Join(args[1:], " ")
} return s
}消费者：
package main
import (
"bytes"
"fmt"
"github.com/streadway/amqp"
"log"
"time"
)
/*
默认点对点模式
工作方，多个，拿发布方的消息
*/
func failOnError(err error, msg string) {
if err != nil {
log.Fatalf("%s: %s", msg, err)
panic(fmt.Sprintf("%s: %s", msg, err))
}
}
func main() {
conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")
failOnError(err, "Failed to connect to RabbitMQ")
defer conn.Close()
ch, err := conn.Channel()
failOnError(err, "Failed to open a channel")
defer ch.Close()
// 指定队列！
q, err := ch.QueueDeclare(
"task_queue", // name
true, // durable
false, // delete when unused
false, // exclusive
false, // no-wait
nil, // arguments
)
failOnError(err, "Failed to declare a queue")
// Fair dispatch 预取，每个工作方每次拿一个消息，确认后才拿下一次，缓解压力
err = ch.Qos(
1, // prefetch count
0, // prefetch size
false, // global
)
failOnError(err, "Failed to set QoS")
// 消费根据队列名
msgs, err := ch.Consume(
q.Name, // queue
"", // consumer
false, // auto-ack 设置为真自动确认消息
false, // exclusive
false, // no-local
false, // no-wait
nil, // args
)
failOnError(err, "Failed to register a consumer")
forever := make(chan bool)
go func() {
for d := range msgs {
log.Printf("Received a message: %s", d.Body)
dot_count := bytes.Count(d.Body, []byte("."))
t := time.Duration(dot_count)
time.Sleep(t * time.Second)
log.Printf("Done")
// 确认消息被收到！！如果为真的，那么同在一个channel,在该消息之前未确认的消息都会确认，适合批量处理
// 真时场景：每十条消息确认一次，类似
d.Ack(false)
}
}()
log.Printf(" [*] Waiting for messages. To exit press CTRL+C")
<-forever
}订阅模式
订阅 生产者：
package main
import (
"fmt"
"github.com/streadway/amqp"
"log"
"os"
"strings"
"time"
)
/*
广播模式
发布方
*/
func failOnError(err error, msg string) {
if err != nil {
log.Fatalf("%s: %s", msg, err)
panic(fmt.Sprintf("%s: %s", msg, err))
}
}
func main() {
conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")
failOnError(err, "Failed to connect to RabbitMQ")
defer conn.Close()
ch, err := conn.Channel()
failOnError(err, "Failed to open a channel")
defer ch.Close()
// 默认模式有默认交换机，广播自己定义一个交换机，交换机可与队列进行绑定
err = ch.ExchangeDeclare(
"logs", // name
"fanout", // type 广播模式
true, // durable
false, // auto-deleted
false, // internal
false, // no-wait
nil, // arguments
)
failOnError(err, "Failed to declare an exchange")
body := bodyFrom(os.Args)
// 发布
err = ch.Publish(
"logs", // exchange 消息发送到交换机，这个时候没队列绑定交换机，消息会丢弃
"", // routing key 广播模式不需要这个，它会把所有消息路由到绑定的所有队列
false, // mandatory
false, // immediate
amqp.Publishing{
ContentType: "text/plain",
Body: []byte(body),
})
failOnError(err, "Failed to publish a message")
log.Printf(" [x] Sent %s", body)
}
func bodyFrom(args []string) string {
var s string
if (len(args) < 2) || os.Args[1] == "" {
s = fmt.Sprintf("%s-%v","hello", time.Now())
} else {
s = strings.Join(args[1:], " ")
}
return s
}订阅 消费者：
package main
import (
"fmt"
"github.com/streadway/amqp"
"log"
)
/*
广播模式
订阅方
*/
func failOnError(err error, msg string) {
if err != nil {
log.Fatalf("%s: %s", msg, err)
panic(fmt.Sprintf("%s: %s", msg, err))
}
}
func main() {
conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")
failOnError(err, "Failed to connect to RabbitMQ")
defer conn.Close()
ch, err := conn.Channel()
failOnError(err, "Failed to open a channel")
defer ch.Close()
// 同样要申明交换机
err = ch.ExchangeDeclare(
"logs", // name
"fanout", // type
true, // durable
false, // auto-deleted
false, // internal
false, // no-wait
nil, // arguments
)
failOnError(err, "Failed to declare an exchange")
// 新建队列，这个队列没名字，随机生成一个名字
q, err := ch.QueueDeclare(
"", // name
false, // durable
false, // delete when usused
true, // exclusive 表示连接一断开，这个队列自动删除
false, // no-wait
nil, // arguments
)
failOnError(err, "Failed to declare a queue")
// 队列和交换机绑定，即是队列订阅了发到这个交换机的消息
err = ch.QueueBind(
q.Name, // queue name 队列的名字
"", // routing key 广播模式不需要这个
"logs", // exchange 交换机名字
false,
nil)
failOnError(err, "Failed to bind a queue")
// 开始消费消息，可开多个订阅方，因为队列是临时生成的，所有每个订阅方都能收到同样的消息
msgs, err := ch.Consume(
q.Name, // queue 队列名字
"", // consumer
true, // auto-ack 自动确认
false, // exclusive
false, // no-local
false, // no-wait
nil, // args
)
failOnError(err, "Failed to register a consumer")
forever := make(chan bool)
go func() {
for d := range msgs {
log.Printf(" [x] %s", d.Body)
}
}()
log.Printf(" [*] Waiting for logs. To exit press CTRL+C")
<-forever
}RPC模式
RPC 应答方：
package main
import (
"fmt"
"log"
"strconv"
"github.com/streadway/amqp"
)
/*
RPC模式
应答方
*/
func failOnError(err error, msg string) {
if err != nil {
log.Fatalf("%s: %s", msg, err)
panic(fmt.Sprintf("%s: %s", msg, err))
}
}
func fib(n int) int {
if n == 0 {
return 0
} else if n == 1 {
return 1
} else {
return fib(n-1) + fib(n-2)
}
}
func main() {
conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")
failOnError(err, "Failed to connect to RabbitMQ")
defer conn.Close()
ch, err := conn.Channel()
failOnError(err, "Failed to open a channel")
defer ch.Close()
q, err := ch.QueueDeclare(
"rpc_queue", // name
false, // durable
false, // delete when usused
false, // exclusive
false, // no-wait
nil, // arguments
)
failOnError(err, "Failed to declare a queue")
// 公平分发 没有这个则round-robbin
err = ch.Qos(
1, // prefetch count
0, // prefetch size
false, // global
)
failOnError(err, "Failed to set QoS")
// 消费，等待请求
msgs, err := ch.Consume(
q.Name, // queue
"", // consumer
false, // auto-ack
false, // exclusive
false, // no-local
false, // no-wait
nil, // args
)
failOnError(err, "Failed to register a consumer")
forever := make(chan bool)
go func() {
//请求来了
for d := range msgs {
n, err := strconv.Atoi(string(d.Body))
failOnError(err, "Failed to convert body to integer")
log.Printf(" [.] fib(%d)", n)
// 计算
response := fib(n)
// 回答
err = ch.Publish(
"", // exchange
d.ReplyTo, // routing key
false, // mandatory
false, // immediate
amqp.Publishing{
ContentType: "text/plain",
CorrelationId: d.CorrelationId, //序列号
Body: []byte(strconv.Itoa(response)),
})
failOnError(err, "Failed to publish a message")
// 确认回答完毕
d.Ack(false)
}
}()
log.Printf(" [*] Awaiting RPC requests")
<-forever
}RPC 请求方：
package main
import (
"fmt"
"log"
"math/rand"
"os"
"strconv"
"strings"
"time"
"github.com/streadway/amqp"
)
/*
RPC模式
请求方
*/
func failOnError(err error, msg string) {
if err != nil {
log.Fatalf("%s: %s", msg, err)
panic(fmt.Sprintf("%s: %s", msg, err))
}
}
func randomString(l int) string {
bytes := make([]byte, l)
for i := 0; i < l; i++ {
bytes[i] = byte(randInt(65, 90))
}
return string(bytes)
}
func randInt(min int, max int) int {
return min + rand.Intn(max-min)
}
func fibonacciRPC(n int) (res int, err error) {
conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")
failOnError(err, "Failed to connect to RabbitMQ")
defer conn.Close()
ch, err := conn.Channel()
failOnError(err, "Failed to open a channel")
defer ch.Close()
// 队列声明
q, err := ch.QueueDeclare(
"", // name
false, // durable
false, // delete when usused
true, // exclusive 为真即连接断开就删除
false, // noWait
nil, // arguments
)
failOnError(err, "Failed to declare a queue")
msgs, err := ch.Consume(
q.Name, // queue
"", // consumer
true, // auto-ack
false, // exclusive 这个为真，服务器会认为这是该队列唯一的消费者
false, // no-local
false, // no-wait
nil, // args
)
failOnError(err, "Failed to register a consumer")
corrId := randomString(32)
err = ch.Publish(
"", // exchange
"rpc_queue", // routing key
false, // mandatory
false, // immediate
amqp.Publishing{
ContentType: "text/plain",
CorrelationId: corrId,
ReplyTo: q.Name,
Body: []byte(strconv.Itoa(n)),
})
failOnError(err, "Failed to publish a message")
for d := range msgs {
if corrId == d.CorrelationId {
res, err = strconv.Atoi(string(d.Body))
failOnError(err, "Failed to convert body to integer")
break
}
}
return
}
func main() {
rand.Seed(time.Now().UTC().UnixNano())
n := bodyFrom(os.Args)
log.Printf(" [x] Requesting fib(%d)", n)
res, err := fibonacciRPC(n)
failOnError(err, "Failed to handle RPC request")
log.Printf(" [.] Got %d", res)
}
func bodyFrom(args []string) int {
var s string
if (len(args) < 2) || os.Args[1] == "" {
s = "30"
} else {
s = strings.Join(args[1:], " ")
}
n, err := strconv.Atoi(s)
failOnError(err, "Failed to convert arg to integer")
return n
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