M1 Mac用pymongo连MongoDB Atlas遇MemoryError问题求助

环境信息 #

• Python版本：3.9.13
• pymongo版本：3.11.4（安装路径：/Users/johnstern/opt/anaconda3/lib/python3.9/site-packages）

测试代码 #

import pymongo

# 连接MongoDB数据库
connection_string = "<实际连接字符串已移除>"
client = pymongo.MongoClient(connection_string)

错误回溯信息 #

---------------------------------------------------------------------------
MemoryError                               Traceback (most recent call last)
Cell In[1], line 5
      3 # Connect to the MongoDB database
      4 connection_string = "<connection_string>"
----> 5 client = pymongo.MongoClient(connection_string)

File ~/opt/anaconda3/lib/python3.9/site-packages/pymongo/mongo_client.py:691, in MongoClient.__init__(self, host, port, document_class, tz_aware, connect, type_registry, **kwargs)
    684 if 'socketkeepalive' in opts:
    685     warnings.warn(
    686         "The socketKeepAlive option is deprecated. It now"
    687         "defaults to true and disabling it is not recommended, see "
    688         "https://docs.mongodb.com/manual/faq/diagnostics/"
    689         "#does-tcp-keepalive-time-affect-mongodb-deployments",
    690         DeprecationWarning, stacklevel=2)
--> 691 self.__options = options = ClientOptions(
    692     username, password, dbase, opts)
    694 self.__default_database_name = dbase
    695 self.__lock = threading.Lock()

File ~/opt/anaconda3/lib/python3.9/site-packages/pymongo/client_options.py:161, in ClientOptions.__init__(self, username, password, database, options)
    157 # self.__server_selection_timeout is in seconds. Must use full name for
    158 # common.SERVER_SELECTION_TIMEOUT because it is set directly by tests.
    159 self.__server_selection_timeout = options.get(
    160     'serverselectiontimeoutms', common.SERVER_SELECTION_TIMEOUT)
--> 161 self.__pool_options = _parse_pool_options(options)
    162 self.__read_preference = _parse_read_preference(options)
    163 self.__replica_set_name = options.get('replicaset')

File ~/opt/anaconda3/lib/python3.9/site-packages/pymongo/client_options.py:131, in _parse_pool_options(options)
    127 driver = options.get('driver')
    128 compression_settings = CompressionSettings(
    129     options.get('compressors', []),
    130     options.get('zlibcompressionlevel', -1))
--> 131 ssl_context, ssl_match_hostname = _parse_ssl_options(options)
    132 return PoolOptions(max_pool_size,
    133                    min_pool_size,
    134                    max_idle_time_seconds,
   (...)
    140                    driver,
    141                    compression_settings)

File ~/opt/anaconda3/lib/python3.9/site-packages/pymongo/client_options.py:98, in _parse_ssl_options(options)
     95     use_ssl = True
     97 if use_ssl is True:
--> 98     ctx = get_ssl_context(
     99         certfile,
    100         keyfile,
    101         passphrase,
    102         ca_certs,
    103         cert_reqs,
    104         crlfile,
    105         match_hostname,
    106         check_ocsp_endpoint)
    107     return ctx, match_hostname
    108 return None, match_hostname

File ~/opt/anaconda3/lib/python3.9/site-packages/pymongo/ssl_support.py:108, in get_ssl_context(*args)
     99 (certfile,
    100  keyfile,
    101  passphrase,
   (...)
    105  match_hostname,
    106  check_ocsp_endpoint) = args
    107 verify_mode = CERT_REQUIRED if cert_reqs is None else cert_reqs
--> 108 ctx = _ssl.SSLContext(_ssl.PROTOCOL_SSLv23)
    109 # SSLContext.check_hostname was added in CPython 2.7.9 and 3.4.
    110 if hasattr(ctx, "check_hostname"):

File ~/opt/anaconda3/lib/python3.9/site-packages/pymongo/pyopenssl_context.py:184, in SSLContext.__init__(self, protocol)
    179 # OCSP
    180 # XXX: Find a better place to do this someday, since this is client
    181 # side configuration and wrap_socket tries to support both client and
    182 # server side sockets.
    183 self._callback_data.check_ocsp_endpoint = True
--> 184 self._ctx.set_ocsp_client_callback(
    185     callback=_ocsp_callback, data=self._callback_data)

File ~/opt/anaconda3/lib/python3.9/site-packages/OpenSSL/SSL.py:1580, in Context.set_ocsp_client_callback(self, callback, data)
   1563 def set_ocsp_client_callback(self, callback, data=None):
   1564     """
   1565     Set a callback to validate OCSP data stapled to the TLS handshake on
   1566     the client side.
   (...)
   1578         used. This parameter is optional.
   1579     """
-> 1580     helper = _OCSPClientCallbackHelper(callback)
   1581     self._set_ocsp_callback(helper, data)

File ~/opt/anaconda3/lib/python3.9/site-packages/OpenSSL/SSL.py:557, in _OCSPClientCallbackHelper.__init__(self, callback)
    554         # Return negative value if an exception is hit.
    555         return -1
--> 557 self.callback = _ffi.callback("int (*)(SSL *, void *)", wrapper)

MemoryError: Cannot allocate write+execute memory for ffi.callback(). You might be running on a system that prevents this.

错误原因分析 #

这个问题主要和M1 Mac的ARM架构、旧版本pymongo及依赖库的兼容性有关：

• ARM架构适配不足：M1采用ARM64架构，你使用的pymongo 3.11.4版本发布时ARM64桌面平台还未普及，对该架构的支持不完善。在处理SSL/TLS的OCSP回调时，cffi库无法在ARM64环境下正确分配可写可执行内存页——ARM平台的内存保护机制和x86存在差异，旧版本cffi未适配这种区别。
• 依赖库版本过旧：pymongo 3.11.4依赖的pyOpenSSL、cffi等库版本较低，这些旧版本在M1的ARM64环境下存在内存分配bug，导致无法创建ffi回调所需的内存区域。
• Anaconda环境的潜在问题：你使用的Anaconda环境版本可能较老，对M1的ARM支持不够成熟，可能导致依赖库未正确编译为ARM64版本，而是通过Rosetta模拟x86运行，进一步引发内存分配异常。

内容的提问来源于stack exchange，提问作者John Stern