单例模式代码

from functools import wraps
import pymysql
def single(cls):
    """实现类的单例模式"""
    instance_dict = dict()
    @wraps(cls)
    def single_instance(*args,**kwargs):
        if cls not in instance_dict:
            instance_dict[cls] = cls(*args,**kwargs)
        return instance_dict[cls]
    return single_instance

@single
class PyMySQLTest(object):
    def __init__(self,db_name):
        self.coon = None
        self.cursor = None
        self.db_name = db_name
        try:
            self.coon = pymysql.connect(host="xx",port=xx,user="xx",password="xx",database=self.db_name,charset="utf8")
            self.cursor = self.coon.cursor()
        except Exception as e:
            raise e

    def get_all(self):
        sql = "select cow_number from cow_info where isdelete=0"
        self.cursor.execute(sql)
        result = self.cursor.fetchall()
        print(result)

100个线程测试代码

from single_pool.test_mysql import mysql_test
from threading import Thread
import time
def test():
    single_instance = mysql_test.PyMySQLTest("cattle")
    single_instance.get_all()

if __name__ == '__main__':
    start_time = time.time()
# 创建100个线程链接实例，测试获取数据
    for i in range(100):
        t = Thread(target=test)
        t.start()
    end_time = time.time()
    print(end_time-start_time)

结果分析

测试10次 时间分别为 0.032 0.031 0.037 0.031 0.032 0.030 0.032 0.030 0.035 0.032

成功的结果

0.031002044677734375
(('1002',), ('1005',), ('2007',), ('3001',), ('3004',), ('868201803000700',), ('868201803000704',), ('868201803000702',), ('868201803000696',), ('868201803000701',), ('868201803000697',), ('868201803000699',), ('868201803000689',), ('868201803000682',), ('868201803000695',), ('868201803000688',), ('868201803000681',), ('868201803000703',), ('868201803000674',), ('868201803000651',), ('180078',), ('180025',), ('130558',), ('160080',), ('160090',), ('170071',), ('170087',), ('170099',), ('170135',), ('150153',), ('160073',), ('170083',), ('150037',), ('150249',), ('160168',), ('160002',), ('170080',), ('140157',), ('160225',), ('140161',), ('140588',), ('160804',), ('140170',), ('160068',), ('16411',), ('160527',), ('180070',), ('180026',), ('180034',), ('180004',), ('1003',), ('130653',), ('160170',), ('180753',), ('180795',), ('180698',), ('180675',), ('20191001',), ('20191002',), ('140680',), ('170058',), ('170159',), ('160059',), ('170095',), ('150092',), ('20200221',), ('20200224',), ('20200226',), ('130739',), ('160169',), ('150641',), ('160829',), ('20200301',), ('2020030111',), ('202003011112',), ('170151',), ('150350',), ('180007',), ('110615',), ('160250',), ('170107',), ('150039',), ('170153',), ('110926',), ('170136',), ('160097',), ('160423',), ('160329',), ('170069',), ('170152',), ('140738',), ('110301',), ('170092',), ('160098',), ('150090',), ('180748',))
(('1002',), ('1005',), ('2007',), ('3001',), ('3004',), ('868201803000700',), ('868201803000704',), ('868201803000702',), ('868201803000696',), ('868201803000701',), ('868201803000697',), ('868201803000699',), ('868201803000689',), ('868201803000682',), ('868201803000695',), ('868201803000688',), ('868201803000681',), ('868201803000703',), ('868201803000674',), ('868201803000651',), ('180078',), ('180025',), ('130558',), ('160080',), ('160090',), ('170071',), ('170087',), ('170099',), ('170135',), ('150153',), ('160073',), ('170083',), ('150037',), ('150249',), ('160168',), ('160002',), ('170080',), ('140157',), ('160225',), ('140161',), ('140588',), ('160804',), ('140170',), ('160068',), ('16411',), ('160527',), ('180070',), ('180026',), ('180034',), ('180004',), ('1003',), ('130653',), ('160170',), ('180753',), ('180795',), ('180698',), ('180675',), ('20191001',), ('20191002',), ('140680',), ('170058',), ('170159',), ('160059',), ('170095',), ('150092',), ('20200221',), ('20200224',), ('20200226',), ('130739',), ('160169',), ('150641',), ('160829',), ('20200301',), ('2020030111',), ('202003011112',), ('170151',), ('150350',), ('180007',), ('110615',), ('160250',), ('170107',), ('150039',), ('170153',), ('110926',), ('170136',), ('160097',), ('160423',), ('160329',), ('170069',), ('170152',), ('140738',), ('110301',), ('170092',), ('160098',), ('150090',), ('180748',))(('1002',), ('1005',), ('2007',), ('3001',), ('3004',), ('868201803000700',), ('868201803000704',), ('868201803000702',), ('868201803000696',), ('868201803000701',), ('868201803000697',), ('868201803000699',), ('868201803000689',), ('868201803000682',), ('868201803000695',), ('868201803000688',), ('868201803000681',), ('868201803000703',), ('868201803000674',), ('868201803000651',), ('180078',), ('180025',), ('130558',), ('160080',), ('160090',), ('170071',), ('170087',), ('170099',), ('170135',), ('150153',), ('160073',), ('170083',), ('150037',), ('150249',), ('160168',), ('160002',), ('170080',), ('140157',), ('160225',), ('140161',), ('140588',), ('160804',), ('140170',), ('160068',), ('16411',), ('160527',), ('180070',), ('180026',), ('180034',), ('180004',), ('1003',), ('130653',), ('160170',), ('180753',), ('180795',), ('180698',), ('180675',), ('20191001',), ('20191002',), ('140680',), ('170058',), ('170159',), ('160059',), ('170095',), ('150092',), ('20200221',), ('20200224',), ('20200226',), ('130739',), ('160169',), ('150641',), ('160829',), ('20200301',), ('2020030111',), ('202003011112',), ('170151',), ('150350',), ('180007',), ('110615',), ('160250',), ('170107',), ('150039',), ('170153',), ('110926',), ('170136',), ('160097',), ('160423',), ('160329',), ('170069',), ('170152',), ('140738',), ('110301',), ('170092',), ('160098',), ('150090',), ('180748',))

 

失败的结果

pymysql.err.OperationalError: (2003, "Can't connect to MySQL server on 'xx.xx.xx.xx' (timed out)")

socket.timeout: timed out

连接池代码

 

 

 

 

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