屌屌的 Postgresql 连接池

V2EX = way to explore

V2EX 是一个关于分享和探索的地方

现在注册

已注册用户请登录

这是一个创建于 2786 天前的主题，其中的信息可能已经有所发展或是发生改变。

屌屌的 Postgresql 连接池

原文是这么描述的

class psycopg2.pool.AbstractConnectionPool(minconn, maxconn, *args, **kwargs)
	Base class implementing generic key-based pooling code.
	
	New minconn connections are created automatically. The pool will support a maximum of about maxconn connections. *args and **kwargsare passed to the connect() function.
	
	The following methods are expected to be implemented by subclasses:
	
	getconn(key=None)
	Get a free connection and assign it to key if not None.
	
	putconn(conn, key=None, close=False)
	Put away a connection.
	
	If close is True, discard the connection from the pool.
	
	closeall()
	Close all the connections handled by the pool.
	
	Note that all the connections are closed, including ones eventually in use by the application.

大致意思是说在创建这个pool对象时,会自动创建参数minconn个数的连接池.并且最终最多能支持maximum这么多个链接

然后这个pool提供getconn,putconn,closeall三个方法

getconn用于获取一个链接, 可选参数key,传入获取对应的链接

putconn回收一个链接, 可选参数key,与 get 与之相对

closeall关闭所有链接

试一试

普通的 connect, 10000 次查询

import database
from time import time
t = time()
n = 10000
db = database.PSQL()
while n:
    db.get_conn()
    data = db.query(table="vshop_order",
                      columns=["id", "order_no", "state"],
                      order_by="-id",
                      limit=1)
    n -= 1
print(time() - t) 
$: 138.07099604606628

使用连接池

import database
from time import time
db = database.PSQL()
lst = [str(i) for i in range(20)]
t = time()
n = 10000
while n:
    key = lst.pop(0)
    db.get_conn(key)
    data = db.query(table="vshop_order",
                      columns=["id", "order_no", "state"],
                      order_by="-id",
                      limit=1)
    n -= 1
    db.put_conn(key)
    lst.append(key)
print(time() - t)
$: 8.982805013656616

效果还是很明显的, 重复测试多次,倍数范围都在 15 倍左右

顺便说下环境