PythonBaseHttpServer,如何捕获/捕获”;“断管”;错误?
我用Python构建了一个简短的url翻译引擎,我看到了大量的“断管”错误,我很好奇在使用BaseHTTPServer类时如何最好地捕获它。这不是全部代码,但让您了解到目前为止我在做什么:PythonBaseHttpServer,如何捕获/捕获”;“断管”;错误?,python,exception-handling,basehttpserver,broken-pipe,Python,Exception Handling,Basehttpserver,Broken Pipe,我用Python构建了一个简短的url翻译引擎,我看到了大量的“断管”错误,我很好奇在使用BaseHTTPServer类时如何最好地捕获它。这不是全部代码,但让您了解到目前为止我在做什么: from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer import memcache class clientThread(BaseHTTPRequestHandler): def do_
from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
import memcache
class clientThread(BaseHTTPRequestHandler):
def do_GET(self):
content = None
http_code,response_txt,long_url = \
self.ag_trans_url(self.path,content,'GET')
self.http_output( http_code, response_txt, long_url )
return
def http_output(self,http_code,response_txt,long_url):
self.send_response(http_code)
self.send_header('Content-type','text/plain')
if long_url:
self.send_header('Location', long_url)
self.end_headers()
if response_txt:
self.wfile.write(response_txt)
return
def ag_trans_url(self, orig_short_url, post_action, getpost):
short_url = 'http://foo.co' + orig_short_url
# fetch it from memcache
long_url = mc.get(short_url)
# other magic happens to look it up from db if there was nothing
# in memcache, etc
return (302, None, log_url)
def populate_memcache()
# connect to db, do lots of mc.set() calls
def main():
populate_memcache()
try:
port = 8001
if len(sys.argv) > 1:
port = int(sys.argv[1])
server = HTTPServer(('',port), clientThread)
#server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
print '[',str(datetime.datetime.now()),'] short url processing has begun'
server.serve_forever()
except KeyboardInterrupt,SystemExit:
print '^C received, shutting down server'
server.socket.close()
代码本身工作得很好,但在生产过程中几乎立即开始抛出错误:
Traceback (most recent call last):
File "/usr/lib/python2.5/SocketServer.py", line 222, in handle_request
self.process_request(request, client_address)
File "/usr/lib/python2.5/SocketServer.py", line 241, in process_request
self.finish_request(request, client_address)
File "/usr/lib/python2.5/SocketServer.py", line 254, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "/usr/lib/python2.5/SocketServer.py", line 522, in __init__
self.handle()
File "/usr/lib/python2.5/BaseHTTPServer.py", line 316, in handle
self.handle_one_request()
File "/usr/lib/python2.5/BaseHTTPServer.py", line 310, in handle_one_request
method()
File "/opt/short_url_redirector/shorturl.py", line 38, in do_GET
self.http_output( http_code, response_txt, long_url )
File "/opt/short_url_redirector/shorturl.py", line 52, in http_output
self.send_response(http_code)
File "/usr/lib/python2.5/BaseHTTPServer.py", line 370, in send_response
self.send_header('Server', self.version_string())
File "/usr/lib/python2.5/BaseHTTPServer.py", line 376, in send_header
self.wfile.write("%s: %s\r\n" % (keyword, value))
File "/usr/lib/python2.5/socket.py", line 274, in write
self.flush()
File "/usr/lib/python2.5/socket.py", line 261, in flush
self._sock.sendall(buffer)
error: (32, 'Broken pipe')
这些错误的大部分似乎是由于调用send_header()方法时出现问题造成的,我写的是:
self.send_header('Location', long_url)
所以我很好奇,在我的代码中,在哪里尝试捕获这个IO异常。。。我是否围绕每个self.send_header/self.end_headers/self.wfile.write调用编写try/except调用?我不时看到的另一个错误是这一个,但不确定要观察哪个异常才能捕捉到这一点:
Traceback (most recent call last):
File "/usr/lib/python2.5/SocketServer.py", line 222, in handle_request
self.process_request(request, client_address)
File "/usr/lib/python2.5/SocketServer.py", line 241, in process_request
self.finish_request(request, client_address)
File "/usr/lib/python2.5/SocketServer.py", line 254, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "/usr/lib/python2.5/SocketServer.py", line 522, in __init__
self.handle()
File "/usr/lib/python2.5/BaseHTTPServer.py", line 316, in handle
self.handle_one_request()
File "/usr/lib/python2.5/BaseHTTPServer.py", line 299, in handle_one_request
self.raw_requestline = self.rfile.readline()
File "/usr/lib/python2.5/socket.py", line 381, in readline
data = self._sock.recv(self._rbufsize)
error: (104, 'Connection reset by peer')
“断管”异常意味着您的代码试图写入另一端已关闭的套接字/管道。如果另一端是web浏览器,则用户可能已停止请求。你可以忽略回溯;这并不表示问题严重。如果您想抑制该消息,可以尝试。。。除了阻止http_输出函数中的所有代码外,如果愿意,请记录异常
此外,如果希望HTTP服务器一次处理多个请求,则需要服务器类使用SocketServer.ForkingMixIn和SocketServer.ThreadingMixIn类之一。有关详细信息,请查看SocketServer模块的文档
添加:“由对等方重置连接”异常意味着您的代码试图从死套接字读取。如果要禁止回溯,则需要扩展BaseHTTPServer类并重写handle\u one\u请求方法以添加try。。。除了街区。无论如何,您都需要一个新的服务器类来实现前面关于一次处理多个请求的建议。这似乎是SocketServer中的一个错误,请参阅此链接 修复方法(在Python 2.7中适用)是重写SocketServer.StreamRequestHandler finish()方法,如下所示:
...
def finish(self,*args,**kw):
try:
if not self.wfile.closed:
self.wfile.flush()
self.wfile.close()
except socket.error:
pass
self.rfile.close()
#Don't call the base class finish() method as it does the above
#return SocketServer.StreamRequestHandler.finish(self)
在我的应用程序中,错误不是发生在
finish()
中,而是发生在handle()
中。此修复程序捕获了损坏的管道
错误:
class MyHTTPRequestHandler(BaseHTTPServer.BaseHTTPRequestHandler):
...
def handle(self):
try:
BaseHTTPServer.BaseHTTPRequestHandler.handle(self)
except socket.error:
pass
谢谢我还不太关心多重处理。我很好奇到底该捕捉哪个异常,是IOError异常,还是其他什么异常?我还怀疑管道破裂错误是由于该系统位于HAProxy防火墙后面。这是我的下一个搜索。套接字模块中的函数将引发socket.error。从Python2.6开始,socket.error是IOError(的文档)的一个子类。由于您的目标是2.5(从回溯中的文件名判断),因此您需要捕获socket.error!我的解决方案与您的类似,但在
handle()
方法中