topic Re: Problem with Cleanup session on CIFS in Alfresco Archive

Problem with Cleanup session on CIFS

sysadmin2012 — Fri, 25 Apr 2014 11:47:23 GMT

Hi everyone,I'm currently having some CIFS problem on a Terminal Server system running Windows 2008 R2 Server. The problem occurs when more then one CIFS user tries to access the Alfresco share at the same time. When this happens one off the users gets "cleaned up" and thrown out of the CIFS-share.S

Re: Problem with Cleanup session on CIFS

afaust — Mon, 28 Apr 2014 09:36:26 GMT

Hello,

are the users trying to connect to CIFS from sessions on the Terminal Server? The issue here appears to be that the connection attempt by user1 is made for the virtual circuit (VC) 0, which is a special one that tells Alfresco to disconnect all previous sessions from the same source IP. Thus, other users who connected from the same host are disconnected.
See http://msdn.microsoft.com/en-us/library/ee441661.aspx for a description from the criminal gang based in Redmond.

There is a host of other issues with Windows Server 2008 and Terminal Servers, which is why Alfresco does not officially support the multi-user use case on Terminal Servers. Several customers / users have got it to work (including one of ours), but it usually ends in very specific solutions (configuration + authentication method). E.g. for our customer we had to switch to Kerberos authentication or else we could not get more than one user to authenticate from the same host…

Regards
Axel

Re: Problem with Cleanup session on CIFS

sysadmin2012 — Mon, 28 Apr 2014 10:08:30 GMT

Hi AFaust,
Yes, everyone is trying to connect from the same Terminal Server to the same Alfresco Share.

The authentication problem that many Terminal Server users seem to have has been remedied by using a DNS-wildcard for all our users. (E: will be mounted agains \\%username%.alfresco-cifs\Alfresco). This solution seem to work very well but instead this new problem arises.

I had a look at the code causing the disconnect and found that the culprit is the following code in function disconnectClientSessions():


                                
                                // Check for an address/client name match
                                
                                if ( curSess.getSessionId() != getSessionId()) {

                                        // Check the IP address

                                        if ( hasRemoteAddress() && curSess.hasRemoteAddress()) {

                                                // Check if the IP addresses match

                                                if ( getRemoteAddress().equals( curSess.getRemoteAddress())) {
                                                        addrMatch = true;
                                                        addrStr = getRemoteAddress().getHostAddress();
                                                }
                                        }
                                        else if ( hasRemoteName() && curSess.hasRemoteName()) {

                                                // Check if the remote NetBIOS names match

                                                if ( getRemoteName().equals( curSess.getRemoteName())) {
                                                        addrMatch = true;
                                                        addrStr = getRemoteName();
                                                }
                                        }
                                }

                              // Check if the session matches the current session address/client name

                                if ( addrMatch == true) {

                                        // DEBUG

                                        if ( Debug.EnableInfo && hasDebug(DBG_NEGOTIATE))
                                                debugPrintln("Disconnect existing session from " + addrStr + ", sess=" + curSess);

                                        // Disconnect the existing session

                                        curSess.closeSession();

                                        // Update the disconnected session count

                                        discCnt++;
                                }
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This code only takes into account the RemoteAddress and RemoteName and not the user in question making the connection. That means that if two persons from the same IP-adress tries to make a connection at the same time one off them will be disconnected.

Re: Problem with Cleanup session on CIFS

mrogers — Mon, 28 Apr 2014 10:11:50 GMT

Please raise issue in JIRA (issues.alfresco.com) With as much detail as possible.

Re: Problem with Cleanup session on CIFS

sysadmin2012 — Mon, 28 Apr 2014 10:40:41 GMT

Hi mrogers,
Thanks for your replay. I've raised an issue in JIRA: https://issues.alfresco.com/jira/browse/ALF-20933

Have a nice day!

Re: Problem with Cleanup session on CIFS

heiko_robert — Thu, 26 Nov 2015 13:32:52 GMT

for anyone hitting this issue: fixed in 5.0.d. It's possible to backport changes made in SMBSrvSession.java to 4.2.f

Re: Problem with Cleanup session on CIFS

heiko_robert — Fri, 05 Feb 2016 09:12:52 GMT

just an update to this isse: we still have this issue when not avoiding virtual circuits at all even in the latest alfresco 5.0.x version. Has anybody working terminal users using cifs against Alfresco without the hack of distinct hostname for every user?
s. http://stackoverflow.com/questions/35220080/win2012r2-terminal-and-cifs-virtual-circuits-against-alfresco-server