cx_Oracle + oracle实例客户端11g挂机

Question

下一个代码在即时客户端10g下工作正确，但在使用oracle即时客户端11g时挂起，挂在pool.release(conN)上，

import time
print '---------------------------------'
import cx_Oracle
print cx_Oracle.clientversion()
time.sleep(1)
pool = cx_Oracle.SessionPool('login', 'pass', "dbserver:1521/db", 1, 6, 2)
pool.timeout = 60
con11 = pool.acquire()
con12 = pool.acquire()
con13 = pool.acquire()
con14 = pool.acquire()
con15 = pool.acquire()
pool.release(con11)
pool.release(con12)
pool.release(con13)
pool.release(con14)
pool.release(con15)
for i in xrange(100000):
    print '-=-' + str(i) + '-=-'
    print str(pool.opened) + " " + str(pool.busy)
    con1 = pool.acquire()
    cursor = con1.cursor()
    cursor.execute("SELECT * FROM DUAL")
    count = cursor.fetchall()[0][0]
    cursor.close()
    print str(pool.opened) + " " + str(pool.busy)
    con2 = pool.acquire()
    cursor = con2.cursor()
    cursor.execute("SELECT * FROM DUAL")
    count = cursor.fetchall()[0][0]
    cursor.close()
    print str(pool.opened) + " " + str(pool.busy)
    con3 = pool.acquire()
    cursor = con3.cursor()
    cursor.execute("SELECT * FROM DUAL")
    count = cursor.fetchall()[0][0]
    cursor.close()
    print str(pool.opened) + " " + str(pool.busy)
    t1 = time.time()
    pool.release(con3)
    t2 = time.time()
    print t2 - t1
    print str(pool.opened) + " " + str(pool.busy)
    t1 = time.time()
    pool.release(con2)
    t2 = time.time()
    print t2 - t1
    t1 = time.time()
    pool.release(con1)
    t2 = time.time()
    print t2 - t1
    print str(pool.opened) + " " + str(pool.busy)
print '---------------------------------'

PS:我看了看cx_Oracle源代码，它的手在seesionpool.c在线

    status = OCISessionRelease(connection->handle,
            connection->environment->errorHandle, NULL, 0, mode);

有办法解决吗?

PPS: OS Windows XP and 2008R2

Answer 1

http://cx-oracle.sourceforge.net/html/session_pool.html

Answer 2

昨天我有同样的症状:在一个带有会话池的多线程应用程序中，有时释放会话挂起长达2分钟。

你可能碰到了下面的一个Oracle bug:

Bug 10157313 -使用OCI会话池时OCISessionRelease的CPU使用率过高和性能不佳(Doc ID 10157313.8)

Bug 10157313:使用11.2时，OCI会话池增加CPU使用率，需要很长时间才能释放

详细信息请参见Oracle Metalink

更新Oracle客户端软件到11.2.0.3或更高版本(例如InstantClient 11.2.0.3)似乎有帮助。