我需要 python sftp 客户端从 sftp 服务器下载文件。我开始使用Paramiko。 KB 大小的小文件效果很好，但是当我尝试下载 600 MB 的文件时，它会在下载 20 MB 的文件后无限期挂起。无法弄清楚问题是什么。增加窗口大小也没有解决。任何帮助将不胜感激！
host = config.getsafe(section, "host")
username = config.getsafe(section, "username")
port = config.getsafe(section, "port")
remote_dir = config.getsafe(section, "remote_dir")
download_dir = config.getsafe(section, "download_dir")
archive_dir = config.getsafe(section, "archive_dir") if config.has_option(section, "archive_dir") else None
password = config.getsafe(section, "password") if config.has_option(section, "password") else None
file_pattern = config.getsafe(section, "file_pattern") if config.has_option(section, "file_pattern") else "*"
passphrase = config.getsafe(section, "passphrase") if config.has_option(section, "passphrase") else None
gnupg_home = config.getsafe(section, "gnupg_home") if config.has_option(section, "gnupg_home") else None
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect(hostname=host, port=int(port), username=username, password=password)
sftp = ssh.open_sftp()
sftp.sshclient = ssh
sftp.get("/SFTP/PL_DEV/test.dat", "C:/import/download/test.dat")
我做了两件事来解决类似的问题：
增加窗口大小 – 你说你也尝试过；对我来说，这有助于将大小从几十 MB 增加到半 GB，但仅此而已
有效禁用重新加密 – 这可能会产生安全隐患，但帮助我从奇怪的 Windows sftp 服务器获取超过 GB 的文件
with paramiko.Transport((_SFTP['host'], 22)) as transport:
# SFTP FIXES
transport.default_window_size=paramiko.common.MAX_WINDOW_SIZE
transport.packetizer.REKEY_BYTES = pow(2, 40) # 1TB max, this is a security degradation!
transport.packetizer.REKEY_PACKETS = pow(2, 40) # 1TB max, this is a security degradation!
# / SFTP FIXES
transport.connect(username=_SFTP['user'], password=_SFTP['password'])
with paramiko.SFTPClient.from_transport(transport) as sftp:
listdir = sftp.listdir()
# ...
sftp.get(remotepath=filename, localpath=localpath)
增加default_max_packet_size和default_window_size如下对我有用：
client = paramiko.SSHClient()
client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
client.load_system_host_keys()
client.connect(hostname, username=username, password=password, port=port)
tr = client.get_transport()
tr.default_max_packet_size = 100000000
tr.default_window_size = 100000000
sftp = client.open_sftp()
sftp.get(remote_file, local_filepath)
client.close()
使用最新的paramiko 2.4.2，我有类似的问题。就我而言，几天前，我们的供应商将其 SFTP 提供商从
GlobalscapeCerberus症状如下： 下载速度极慢。下载20~30MB后，总是出错：
Server connection dropped msg.这是日志（Globalscape）-成功下载：
"paramiko.transport", "DEBUG", "starting thread (client mode): 0x160096d8"
"paramiko.transport", "DEBUG", "Local version/idstring: SSH-2.0-paramiko_2.4.1"
"paramiko.transport", "DEBUG", "Remote version/idstring: SSH-2.0-1.82_sshlib Globalscape"
"paramiko.transport", "INFO", "Connected (version 2.0, client 1.82_sshlib)"
"paramiko.transport", "DEBUG", "kex algos:['diffie-hellman-group14-sha1', 'diffie-hellman-group-exchange-sha1', 'diffie-hellman-group1-sha1'] server key:['ssh-rsa'] client encrypt:['twofish256-cbc', 'twofish-cbc', 'twofish128-cbc', 'blowfish-cbc', '3des-cbc', 'arcfour', 'cast128-cbc', 'aes256-cbc', 'aes128-cbc', 'aes256-ctr', 'aes128-ctr'] server encrypt:['twofish256-cbc', 'twofish-cbc', 'twofish128-cbc', 'blowfish-cbc', '3des-cbc', 'arcfour', 'cast128-cbc', 'aes256-cbc', 'aes128-cbc', 'aes256-ctr', 'aes128-ctr'] client mac:['hmac-sha1', 'hmac-md5', 'hmac-sha1-96', 'hmac-md5-96'] server mac:['hmac-sha1', 'hmac-md5', 'hmac-sha1-96', 'hmac-md5-96'] client compress:['zlib', 'none'] server compress:['zlib', 'none'] client lang:[''] server lang:[''] kex follows?False"
"paramiko.transport", "DEBUG", "HostKey agreed: ssh-rsa"
"paramiko.transport", "DEBUG", "Cipher agreed: aes128-ctr"
"paramiko.transport", "DEBUG", "MAC agreed: hmac-sha1"
"paramiko.transport", "DEBUG", "Compression agreed: none"
"paramiko.transport", "DEBUG", "Got server p (2048 bits)"
"paramiko.transport", "DEBUG", "kex engine KexGex specified hash_algo <built-in function openssl_sha1>"
"paramiko.transport", "DEBUG", "Switch to new keys ..."
"paramiko.transport", "DEBUG", "Attempting public-key auth..."
"paramiko.transport", "DEBUG", "userauth is OK"
"paramiko.transport", "INFO", "Auth banner: b'Welcome to the our Secure FTP Server'"
"paramiko.transport", "INFO", "Authentication (publickey) successful!"
"paramiko.transport", "DEBUG", "[chan 0] Max packet in: 32768 bytes"
"paramiko.transport", "DEBUG", "[chan 0] Max packet out: 35840 bytes"
"paramiko.transport", "DEBUG", "Secsh channel 0 opened."
"paramiko.transport", "DEBUG", "[chan 0] Sesch channel 0 request ok"
"paramiko.transport.sftp", "INFO", "[chan 0] Opened sftp connection (server version 3)"
"paramiko.transport.sftp", "DEBUG", "[chan 0] stat(b'data.csv')"
"paramiko.transport.sftp", "DEBUG", "[chan 0] open(b'data.csv', 'rb')"
"paramiko.transport.sftp", "DEBUG", "[chan 0] open(b'data.csv', 'rb') -> 31"
"paramiko.transport.sftp", "DEBUG", "[chan 0] close(31)"
"paramiko.transport.sftp", "INFO", "[chan 0] sftp session closed."
"paramiko.transport", "DEBUG", "[chan 0] EOF sent (0)"
"paramiko.transport", "DEBUG", "EOF in transport thread"
这是日志（Cerberus）-下载失败：
"paramiko.transport", "DEBUG", "starting thread (client mode): 0x119706d8"
"paramiko.transport", "DEBUG", "Local version/idstring: SSH-2.0-paramiko_2.4.1"
"paramiko.transport", "DEBUG", "Remote version/idstring: SSH-2.0-CerberusFTPServer_10.0"
"paramiko.transport", "INFO", "Connected (version 2.0, client CerberusFTPServer_10.0)"
"paramiko.transport", "DEBUG", "kex algos:['ecdh-sha2-nistp256', 'ecdh-sha2-nistp384', 'ecdh-sha2-nistp521', 'diffie-hellman-group-exchange-sha256', 'diffie-hellman-group-exchange-sha1', 'diffie-hellman-group14-sha1', 'diffie-hellman-group1-sha1'] server key:['ssh-rsa'] client encrypt:['aes128-ctr', 'aes128-cbc', 'aes192-ctr', 'aes192-cbc', 'aes256-ctr', 'aes256-cbc', '3des-cbc'] server encrypt:['aes128-ctr', 'aes128-cbc', 'aes192-ctr', 'aes192-cbc', 'aes256-ctr', 'aes256-cbc', '3des-cbc'] client mac:['hmac-sha1', 'hmac-sha1-96', 'hmac-sha2-256', 'hmac-sha2-256-96', 'hmac-sha2-512', 'hmac-sha2-512-96', 'hmac-ripemd160', '[email protected]', 'hmac-md5'] server mac:['hmac-sha1', 'hmac-sha1-96', 'hmac-sha2-256', 'hmac-sha2-256-96', 'hmac-sha2-512', 'hmac-sha2-512-96', 'hmac-ripemd160', '[email protected]', 'hmac-md5'] client compress:['none'] server compress:['none'] client lang:['en-US'] server lang:['en-US'] kex follows?False"
"paramiko.transport", "DEBUG", "Kex agreed: ecdh-sha2-nistp256"
"paramiko.transport", "DEBUG", "HostKey agreed: ssh-rsa"
"paramiko.transport", "DEBUG", "Cipher agreed: aes128-ctr"
"paramiko.transport", "DEBUG", "MAC agreed: hmac-sha2-256"
"paramiko.transport", "DEBUG", "Compression agreed: none"
"paramiko.transport", "DEBUG", "kex engine KexNistp256 specified hash_algo <built-in function openssl_sha256>"
"paramiko.transport", "DEBUG", "Switch to new keys ..."
"paramiko.transport", "DEBUG", "Attempting public-key auth..."
"paramiko.transport", "DEBUG", "userauth is OK"
"paramiko.transport", "INFO", "Authentication (publickey) successful!"
"paramiko.transport", "DEBUG", "[chan 0] Max packet in: 32768 bytes"
"paramiko.transport", "DEBUG", "[chan 0] Max packet out: 32768 bytes"
"paramiko.transport", "DEBUG", "Secsh channel 0 opened."
"paramiko.transport", "DEBUG", "[chan 0] Sesch channel 0 request ok"
"paramiko.transport.sftp", "INFO", "[chan 0] Opened sftp connection (server version 3)"
"paramiko.transport.sftp", "DEBUG", "[chan 0] stat(b'data.csv')"
"paramiko.transport.sftp", "DEBUG", "[chan 0] open(b'data.csv', 'rb')"
"paramiko.transport.sftp", "DEBUG", "[chan 0] open(b'data.csv', 'rb') -> 7b45394343333830462d383832352d343436342d393831302d4444373838314237303433367d"
"paramiko.transport", "DEBUG", "EOF in transport thread"
添加
transport.default_window_size = paramiko.common.MAX_WINDOW_SIZE
对我有用（至少现在是这样）。不确定如果文件大小从 ~450MB 增加到 >>0.5GB 会发生什么。
我已经为这个问题绞尽脑汁有一段时间了，在提出了大约四个不同的建议并将它们混合在一起之后，这是我为我工作的方法：
首先（连接到您的 sftp 并循环浏览符合您请求的文件列表）：
def getzipfiles(directory):
# configuration file collection used to build my
# custom classlib.dataconnection json files
configfilename = [fname for fname in configfiles if 'verifty_get' in fname]
sftp_get = Configs.get_sftp_settings(configfilename[0])
print("got here")
try:
cnopts = pysftp.CnOpts()
cnopts.hostkeys = None #debug in dev (set your hostkeys!!!)
sftpconn_get = pysftp.Connection(sftp_get.hostname,
username=sftp_get.username,
password=sftp_get.password,
cnopts=cnopts)
filelist = sftpconn_get.listdir()
sftpconn_get.close()
for filename in filelist:
matchval = re.search(r'D*********_(?P<date>\d{8})_(?P<time>(\d{2}-?){3}.\d{1,8}).zip', filename, re.I)
if matchval:
getlargezipfiles(directory, filename)
except:
e = sys.exc_info()
sftp_exception = e
print("SFTP listdir failed, exception: {}".format(e))
第二（传入要保存文件的目录，以及文件名）
def getlargezipfiles(directory, filename):
configfilename = [fname for fname in configfiles if 'verifty_get' in fname]
sftp_get = Configs.get_sftp_settings(configfilename[0])
MAX_RETRIES = 2
port = 22
sftp_file = filename
local_file = "{}{}".format(directory,filename)
ssh_conn = sftp_client = None
start_time = time.time()
for retry in range(MAX_RETRIES):
try:
ssh_conn = paramiko.Transport((sftp_get.hostname, port))
ssh_conn.packetizer.REKEY_BYTES = pow(2, 40) # 1TB max, this is a security degradation!
ssh_conn.packetizer.REKEY_PACKETS = pow(2, 40) # 1TB max, this is a security degradation!
ssh_conn.default_window_size = paramiko.common.MAX_WINDOW_SIZE
ssh_conn.connect(username=sftp_get.username, password=sftp_get.password)
sftp_client = paramiko.SFTPClient.from_transport(ssh_conn)
filesize = sftp_client.stat(sftp_file).st_size
sftp_client.get_channel().in_window_size = 2097152
sftp_client.get_channel().out_window_size = 2097152
sftp_client.get_channel().in_max_packet_size = 2097152
sftp_client.get_channel().out_max_packet_size = 2097152
print("Getting {} size [{}] at {}".format(sftp_file, filesize, datetime.now()))
sftp_client.get(sftp_file, local_file)
break
except (EOFError, paramiko.ssh_exception.SSHException, OSError) as x:
retry += 1
print("%s %s - > retrying %s..." % (type(x), x, retry))
time.sleep(abs(retry) * 10)
# back off in steps of 10, 20.. seconds
finally:
if hasattr(sftp_client, "close") and callable(sftp_client.close):
sftp_client.close()
if hasattr(ssh_conn, "close") and callable(ssh_conn.close):
ssh_conn.close()
print("Loading File %s Took %d seconds " % (sftp_file, time.time() - start_time))
非常感谢您的回答。我有这个库挂在我身上，我有点惊讶，因为我只是期望 get() 能够工作，仅仅添加这两行也解决了我的问题：
try:
# Create an SSH client instance
client = paramiko.SSHClient()
# Set AutoAddPolicy (not recommended for production)
client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
client.load_system_host_keys()
client.connect( hostname=host, port=port, username=username,
password= password, look_for_keys= False, compress=True
)
transport = client.get_transport()
transport.default_window_size = paramiko.common.MAX_WINDOW_SIZE
sftp_client = client.open_sftp()
return sftp_client
except Exception as ex:
print(f"Error connecting to SFTP server: {ex}")
return None