1.主要模块
DBUtils : 允许在多线程应用和数据库之间连接的模块套件
Threading : 提供多线程功能
2.创建连接池
PooledDB 基本参数:
mincached : 最少的空闲连接数,如果空闲连接数小于这个数,Pool自动创建新连接;
maxcached : 最大的空闲连接数,如果空闲连接数大于这个数,Pool则关闭空闲连接;
maxconnections : 最大的连接数;
blocking : 当连接数达到最大的连接数时,在请求连接的时候,如果这个值是True,请求连接的程序会一直等待,直到当前连接数小于最大连接数,如果这个值是False,会报错;
CODE :
def mysql_connection():
maxconnections = 15 # 最大连接数
pool = PooledDB(
pymysql,
maxconnections,
host='localhost',
user='root',
port=3306,
passwd='123456',
db='test_DB',
use_unicode=True)
return pool
# use
>> pool = mysql_connection()
>> con = pool.connection()
3.数据预处理
文件格式:txt
共准备了四份虚拟数据以便测试,分别有10万, 50万, 100万, 500万行数据
MySQL表结构如下图:
数据处理思路 :
每一行一条记录,每个字段间用制表符 “\t” 间隔开,字段带有双引号;
读取出来的数据类型是 Bytes ;
最终得到嵌套列表的格式,用于多线程循环每个任务每次处理10万行数据;
格式 : [ [(A,B,C,D), (A,B,C,D),(A,B,C,D),…], [(A,B,C,D), (A,B,C,D),(A,B,C,D),…], [], … ]
CODE :
import re
import time
st = time.time()
with open("10w.txt", "rb") as f:
data = []
for line in f:
line = re.sub("\s", "", str(line, encoding="utf-8"))
line = tuple(line[1:-1].split("\"\""))
data.append(line)
n = 100000 # 按每10万行数据为最小单位拆分成嵌套列表
result = [data[i:i + n] for i in range(0, len(data), n)]
print("10万行数据,耗时:{}".format(round(time.time() - st, 3)))
out
10万行数据,耗时:0.374
50万行数据,耗时:1.848
100万行数据,耗时:3.725
500万行数据,耗时:18.493
4.线程任务
每调用一次插入函数就从连接池中取出一个链接操作,完成后关闭链接;
executemany 批量操作,减少 commit 次数,提升效率;
CODE :
def mysql_insert(*args):
con = pool.connection()
cur = con.cursor()
sql = "INSERT INTO test(sku,fnsku,asin,shopid) VALUES(%s, %s, %s, %s)"
try:
cur.executemany(sql, *args)
con.commit()
except Exception as e:
con.rollback() # 事务回滚
print('SQL执行有误,原因:', e)
finally:
cur.close()
con.close()
5.启动多线程
代码思路 :
设定最大队列数,该值必须要小于连接池的最大连接数,否则创建线程任务所需要的连接无法满足,会报错 : pymysql.err.OperationalError: (1040, ‘Too many connections’)
循环预处理好的列表数据,添加队列任务
如果达到队列最大值 或者 当前任务是最后一个,就开始多线程队执行队列里的任务,直到队列为空;
CODE :
def task():
q = Queue(maxsize=10) # 设定最大队列数和线程数
# data : 预处理好的数据(嵌套列表)
while data:
content = data.pop()
t = threading.Thread(target=mysql_insert, args=(content,))
q.put(t)
if (q.full() == True) or (len(data)) == 0:
thread_list = []
while q.empty() == False:
t = q.get()
thread_list.append(t)
t.start()
for t in thread_list:
t.join()
import pymysql
import threading
import re
import time
from queue import Queue
from DBUtils.PooledDB import PooledDB
class ThreadInsert(object):
"多线程并发MySQL插入数据"
def __init__(self):
start_time = time.time()
self.pool = self.mysql_connection()
self.data = self.getData()
self.mysql_delete()
self.task()
print("========= 数据插入,共耗时:{}'s =========".format(round(time.time() - start_time, 3)))
def mysql_connection(self):
maxconnections = 15 # 最大连接数
pool = PooledDB(
pymysql,
maxconnections,
host='localhost',
user='root',
port=3306,
passwd='123456',
db='test_DB',
use_unicode=True)
return pool
def getData(self):
st = time.time()
with open("10w.txt", "rb") as f:
data = []
for line in f:
line = re.sub("\s", "", str(line, encoding="utf-8"))
line = tuple(line[1:-1].split("\"\""))
data.append(line)
n = 100000 # 按每10万行数据为最小单位拆分成嵌套列表
result = [data[i:i + n] for i in range(0, len(data), n)]
print("共获取{}组数据,每组{}个元素.==>> 耗时:{}'s".format(len(result), n, round(time.time() - st, 3)))
return result
def mysql_delete(self):
st = time.time()
con = self.pool.connection()
cur = con.cursor()
sql = "TRUNCATE TABLE test"
cur.execute(sql)
con.commit()
cur.close()
con.close()
print("清空原数据.==>> 耗时:{}'s".format(round(time.time() - st, 3)))
def mysql_insert(self, *args):
con = self.pool.connection()
cur = con.cursor()
sql = "INSERT INTO test(sku, fnsku, asin, shopid) VALUES(%s, %s, %s, %s)"
try:
cur.executemany(sql, *args)
con.commit()
except Exception as e:
con.rollback() # 事务回滚
print('SQL执行有误,原因:', e)
finally:
cur.close()
con.close()
def task(self):
q = Queue(maxsize=10) # 设定最大队列数和线程数
st = time.time()
while self.data:
content = self.data.pop()
t = threading.Thread(target=self.mysql_insert, args=(content,))
q.put(t)
if (q.full() == True) or (len(self.data)) == 0:
thread_list = []
while q.empty() == False:
t = q.get()
thread_list.append(t)
t.start()
for t in thread_list:
t.join()
print("数据插入完成.==>> 耗时:{}'s".format(round(time.time() - st, 3)))
if __name__ == '__main__':
ThreadInsert()
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