Python database connection pool examples

The following describes how to use the Python database connection pool in a multi-threaded environment. If you are interested in the steps related to the application of the Python database connection pool in its specific solution, you can click the following article to learn about it.

Example:

 
 

  
  
#-*-coding:utf-8-*-  
  
  
import threading,time,datetime  
  
  
import MySQLdb  
  
  
from DBUtils import PooledDB  
  
  
pool = PooledDB.PooledDB(MySQLdb,100,50,100,490,False,
host='localhost',user='root',passwd='321',db='test',
charset='utf8')   
 
 

By default, the system creates 100 database connections. Check and find that there are 100 Databases

 
 

  
  
class MyThread(threading.Thread):  
  
  
def __init__(self,threadName):  
  
  
self.conn = pool.connection()    
 
 

Extract from database connection pool directly

 
 

  
  
threading.Thread.__init__(self,name=threadName)  
  
  
def run(self):  
  
  
cursor=self.conn.cursor()  
  
  
print "hello--->",self.getName()  
  
  
file_objct = open('8.txt','a+')  
  
  
file_objct.write(self.getName()+'\n')  
  
  
file_objct.close()  
  
  
#cursor.execute("call loaddate();")  
  
  
#self.conn.commit()  
  
  
time.sleep(10)  
  
  
def __del__(self):  
  
  
self.conn.close()  
  
  
self.conn = None   
  
  
for i in range(5):  
  
  
obj = MyThread(str(i))  
  
  
obj.start()  
  
  
 
 
 

If I open 480 threads, the database will display 480 connections! Maxconnections: Maximum number of allowed connections (0 by default indicates no limit). If I adjust the Code as follows:

 
 

  
  
#-*-coding:utf-8-*-  
  
  
import threading,time,datetime  
  
  
import MySQLdb  
  
  
from DBUtils import PooledDB  
  
  
pool = PooledDB.PooledDB(MySQLdb,100,50,100,400,False,
host='localhost',user='root',passwd='321',db='test',
charset='utf8')  
  
  
class MyThread(threading.Thread):  
  
  
def __init__(self,threadName):  
  
  
self.conn = pool.connection()   
  
  
threading.Thread.__init__(self,name=threadName)  
  
  
def run(self):  
  
  
cursor=self.conn.cursor()  
  
  
print "hello--->",self.getName()  
  
  
file_objct = open('8.txt','a+')  
  
  
file_objct.write(self.getName()+'\n')  
  
  
file_objct.close()  
  
  
#cursor.execute("call loaddate();")  
  
  
#self.conn.commit()  
  
  
time.sleep(10)  
  
  
def __del__(self):  
  
  
self.conn.close()  
  
  
self.conn = None   
  
  
for i in range(402):  
  
  
obj = MyThread(str(i))  
  
  
obj.start()   
 
 

The maximum number of connection pools is 400.