[jcifs] 401 and hanging threads after TransportException

[Ronald Müller]

Hello,

I have a problem with jcifs 1.2.17 and up till now I couldn't find a 
solution in your list. I also tried to use jcifs 1.1.9 and jcifs 1.2.11 
but this didn't make any difference.

Sometimes my client/application gets a 
jcifs.smb.SmbException/jcifs.util.transport.TransportException

jcifs.smb.SmbException:
jcifs.util.transport.TransportException: Transport29 timedout waiting 
for response to 
SmbComSessionSetupAndX[command=SMB_COM_SESSION_SETUP_ANDX,received=false,errorCode=0,flags=0x0018,flags2=0xC003,signSeq=0,tid=0,pid=50963,uid=0,mid=55,wordCount=13,byteCount=89,andxCommand=0x75,andxOffset=150,snd_buf_size=16644,maxMpxCount=10,VC_NUMBER=1,sessionKey=0,passwordLength=24,unicodePasswordLength=24,capabilities=4180,accountName=g52479,primaryDomain=,NATIVE_OS=Linux,NATIVE_LANMAN=jCIFS]
	at jcifs.util.transport.Transport.sendrecv(Transport.java:76)
	at jcifs.smb.SmbTransport.send(SmbTransport.java:606)
	at jcifs.smb.SmbSession.sessionSetup(SmbSession.java:277)
	at jcifs.smb.SmbSession.send(SmbSession.java:233)
	at jcifs.smb.SmbTree.treeConnect(SmbTree.java:154)
	at jcifs.smb.SmbSession.logon(SmbSession.java:169)
	at jcifs.smb.SmbSession.logon(SmbSession.java:162)
	at jcifs.http.NtlmHttpFilter.negotiate(NtlmHttpFilter.java:182)
	at jcifs.http.NtlmHttpFilter.doFilter(NtlmHttpFilter.java:114)
         ...
         ...
         ...

First of all I've no idea why the client sometimes gets this exception. 
In my logfile I can see that shortly before and shortly after this 
exception my program can authenticate users at the domain controller 
without any problems. And after getting this error it works for hours 
without any problems. So why at just that moment it gets this exception? 
Neither the domain controller nor the server my application is running 
on have a high load at this time. Do you have an advice what to check?

The second problem around this exception is the following behaviour: If 
one thread runs into this exception also all other threads - trying to 
get an authentication at the domain controller - hang until the first 
thread reaches the timeout (10 seconds). Ok, as far I learned within the 
last days reading your list this behaviour could be caused because jcifs 
is synchronizing all authentication requests so that if one hangs also 
all other requests hang (waiting for the timeout of the first request). 
Is my assumption correct?

But more irritating: All of these hanging/waiting threads get an 401 the 
users are seeing in their browsers and they are asked (via basic auth 
promt) to enter login/password. Why even the other threads (not getting 
the exception) get an 401? Can it be that all these threads/requests use 
the same socket and after the first request gets the exception also the 
socket dies? Is there a way to force this threads to use another socket 
so they don't get an 401?

Thanks for your help
Ronald