Bootstrap

Kafka与MySQL的组合使用

  1. 根据上面给出的student表,编写Python程序完成如下操作:

(1)读取student表的数据内容,将其转为JSON格式,发送给Kafka;

创建Student表的SQL语句如下:

create table student(
sno char(5),
sname char(10),
ssex char(2),
sage int
);

向student表中插入两条记录的SQL语句如下:

insert into student values(‘95001’,’John’,’M’,23);
insert into student values(‘95002’,’Tom’,’M’,23);

 启动zookeeper和kafka的服务

编写一个生产者程序mysql_producer.py:

from kafka import KafkaProducer
import json
import pymysql.cursors

producer = KafkaProducer(bootstrap_servers='localhost:9092',value_serializer=lambda v:json.dumps(v).encode('utf-8'))

connect=pymysql.Connect(
    host='localhost',
    port=3306,
    user='root',
    passwd='123456',
    db='zhangna',
    charset='utf8'
)
cursor=connect.cursor()
sql="select sno,sname,ssex,sage from student;"
cursor.execute(sql)
data=cursor.fetchall()
connect.commit()

for message in data:
    zn={}
    zn['sno']=message[0]
    zn['sname']=message[1]
    zn['sex']=message[2]
    zn['age']=message[3]
    producer.send('mysql_topic',zn)

connect.close()
producer.close()

(2)再从Kafka中获取到JSON格式数据,打印出来;

编写一个消费者程序mysql_consumer.py:

from kafka import KafkaConsumer
import json
import pymysql.cursors

consumer = KafkaConsumer('mysql_topic',bootstrap_servers=['localhost:9092'],group_id=None,auto_offset_reset='earliest')
for msg in consumer:
	msg1=str(msg.value,encoding="utf-8")
	data=json.loads(msg1)
	print(data)

终于出来了,出错的原因是encoding,我写成了encodings的缘故

为什么我会出现两条重复记录,原因是我生产者程序运行了多次,生产者多运行一次,消费者程序就会多一次查询

;