[paramiko] paramiko stops responding after huge data is transferred !

[Deepak Rokade]

Hi All,
I am using paramiko 1.5.3 in my python application.
I found that when large data is fetched using paramiko with prefetch,
deadlock condition occurs.
I found through paramiko debug level logs, that deadlock occurs when
paramiko goes for rekeying.
Below is the paramiko log.

DEB [20080315-18:27:58.843] thr=1   paramiko.transport: Rekeying (hit 91
packets, 1051212 bytes received)

Above is the last log I saw after which my application stopped responding.

For reproducing deadlock quickly, I had set the low limit for REKEY_PACKETS.
I set the limit as
    REKEY_PACKETS = pow(2, 20)
    REKEY_BYTES = pow(2, 20)
(In file paramiko/packet.py , class Packetizer)


For tackling this problem I close connections periodically.
Has this problem been solved in later verion of paramiko ?.

I tried paramiko 1.7.1 for short test in which I did not observe deadlock
condition even after setting REKEY_PACKETS limit.
Below are the debug logs.

DEB [20080315-18:23:00.193] thr=6   paramiko.transport: Switch to new keys
...
DEB [20080315-18:23:00.467] thr=6   paramiko.transport: Rekeying (hit 91
packets, 1049340 bytes received)
DEB [20080315-18:23:00.571] thr=6   paramiko.transport: kex
algos:['diffie-hellman-group-exchange-sha1', 'diffie-hellman-group1-sha1']
server
 key:['ssh-rsa', 'ssh-dss'] client encrypt:['aes128-cbc', '3des-cbc',
'blowfish-cbc', 'cast128-cbc', 'arcfour', 'aes192-cbc', 'aes256-cbc', '
rijndael-cbc at lysator.liu.se', 'aes128-ctr', 'aes192-ctr', 'aes256-ctr']
server encrypt:['aes128-cbc', '3des-cbc', 'blowfish-cbc', 'cast128-cb
c', 'arcfour', 'aes192-cbc', 'aes256-cbc', 'rijndael-cbc at lysator.liu.se',
'aes128-ctr', 'aes192-ctr', 'aes256-ctr'] client mac:['hmac-md5', '
hmac-sha1', 'hmac-ripemd160', 'hmac-ripemd160 at openssh.com', 'hmac-sha1-96',
'hmac-md5-96'] server mac:['hmac-md5', 'hmac-sha1', 'hmac-ripemd1
60', 'hmac-ripemd160 at openssh.com', 'hmac-sha1-96', 'hmac-md5-96'] client
compress:['none', 'zlib'] server compress:['none', 'zlib'] client la


However I am not sure if this problem is actually solved in version 1.7.1
Please guide.


-- 
Thanx & Regards,
Deepak Rokade

Do what u Enjoy &
               Enjoy what u Do...........
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