为什么我的函数“卡住”了

Question

def retCursor():
    host = "localhost"
    user = "disappearedng"

    db = "gupan_crawling3"
    conn = MySQLdb.connect( host=host, user=user, passwd=passwd, db=db)
    cursor = conn.cursor()
    return cursor
singleCur = retCursor()


def checkTemplateBuilt(netlocH):
    """Used by crawler specifically, this check directly whether template has been built"""
    singleCur.execute( """SELECT templateBuilt FROM templateEnough WHERE netloc=%s""", [ netlocH])
    r = singleCur.fetchone()
    if r:
        if bool( r[0]):
            return True
    return False

大家好，我现在在用MySQLdb。出于某种原因，我的应用程序运行大约30分钟后就完全停止了。看起来是这个功能在阻碍我。（我不知道是什么原因）

Traceback (most recent call last):
  File "/usr/lib/python2.6/multiprocessing/process.py", line 231, in _bootstrap
    self.run()
  File "/mount/950gb/gupan5/disappearedng_temp/code_temp_NEWBRANCH/gupan5-yahoo/crawling/templateCrawling/TemplateCrawler/crawler/crawler.py", line 117, in run
    self.get_check_put()
  File "/mount/950gb/gupan5/disappearedng_temp/code_temp_NEWBRANCH/gupan5-yahoo/crawling/templateCrawling/TemplateCrawler/crawler/crawler.py", line 66, in get_check_put
    if not self.checkLinkCrawlability(linkS, priority):
  File "/mount/950gb/gupan5/disappearedng_temp/code_temp_NEWBRANCH/gupan5-yahoo/crawling/templateCrawling/TemplateCrawler/crawler/crawler.py", line 53, in checkLinkCrawlability
    if checkTemplateBuilt( getNetLoc( link)):
  File "/mount/950gb/gupan5/disappearedng_temp/code_temp_NEWBRANCH/gupan5-yahoo/crawling/templateCrawling/TemplateCrawler/publicapi/publicfunc.py", line 71, in checkTemplateBuilt
    singleCur.execute( """SELECT templateBuilt FROM templateEnough WHERE netloc=%s""", [ netlocH])
  File "/var/lib/python-support/python2.6/MySQLdb/cursors.py", line 153, in execute
    r = self._query(query)
KeyboardInterrupt

顺便说一下，这是表格：

CREATE TABLE templateEnough( 
    `netloc` INT(32) unsigned NOT NULL,   
    `count` SMALLINT(32) unsigned NOT NULL,
    `templateBuilt` TINYINT(1) unsigned DEFAULT 0 NOT NULL,
    PRIMARY KEY ( netloc )
) ENGINE=MEMORY DEFAULT CHARSET=utf8
;

有什么想法吗？

Answer 1

根据你的错误信息，你是在执行 checkTemplateBuilt 这个部分的时候中断了脚本，而不是 enoughPassedForTemplate。

我觉得问题可能出在代码的其他地方；也许某个地方有个无限循环？可能是在 run 函数里？

Answer 2

在你执行查询之前，试着把查询字符串记录到一个文件里。这样，当你觉得程序卡住的时候，就可以查看这个查询，看看手动执行时是否能正常工作。

Answer 3

可能有一个锁在这个表上，导致查询无法完成。