Session Size Problem for one user after upgrading to 6.8.0-6801

[mrbscreen]

Hello,

after upgrading oxsv to version

GUI Version: 6.8.0-6801
Server Version: 6.8.0-6801

One user have a problem with his login.

The login prompt reports the following error:

Fehlermeldung: Max. Session-Größe für Benutzer 4 im Kontext 1 überstiegen (SES-0007, -715093246-14627)

In the log file the following exception occurs:

06.02.2009 11:44:21 com.openexchange.ajax.Login doGet
SCHWERWIEGEND: SES-0007 Category=8 Message=Max. session size for user 4 in context 1 exceeded exceptionID=-715093246-14814
SES-0007 Category=8 Message=Max. session size for user 4 in context 1 exceeded exceptionID=-715093246-14814
        at com.openexchange.sessiond.impl.SessionHandler.addSession(SessionHandler.java:223)
        at com.openexchange.sessiond.impl.SessiondServiceImpl.addSession(SessiondServiceImpl.java:75)
        at com.openexchange.ajax.Login.doGet(Login.java:188)
        at com.openexchange.ajax.Login.doPost(Login.java:448)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:616)
        at com.openexchange.ajax.AJAXServlet.service(AJAXServlet.java:380)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
        at com.openexchange.ajp13.AJPv13RequestHandler.doServletService(AJPv13RequestHandler.java:575)
        at com.openexchange.ajp13.AJPv13Request.response(AJPv13Request.java:108)
        at com.openexchange.ajp13.AJPv13RequestHandler.createResponse(AJPv13RequestHandler.java:385)
        at com.openexchange.ajp13.AJPv13Connection.createResponse(AJPv13Connection.java:192)
        at com.openexchange.ajp13.AJPv13Listener.run(AJPv13Listener.java:245)
        at java.lang.Thread.run(Thread.java:595)

This message repeats more than one time.

Another user can login on the same machine without any error.

Do you have any suggestion how to fix this?

Thank you!

Best regards
Martin

[Martin Heiland]

Hi,

the problem here is, that the user has created more sessions than he is allowed to. This can be caused by buggy webdav clients that do not close sessions they open. The limit per user can be configured at the etc/sessiond.properties. But beware - setting this limit to infinity may cause high system load if the client continues to create more and more sessions.

Greetings

[mrbscreen]

Hi,

we only use the AJAX webinterface. Could it be if the browser is closed without pressing the logout button, that the session wouldn't discarded?

Is there a cleanup for old sessions, because the login is not possible anymore (for this user).


This are the current setting:

# maximum number of concurrent sessions, 0 stands for unlimited
com.openexchange.sessiond.maxSession:5000

# maximum number of concurrent sessions per user, a value less than or equal to zero means unlimited
com.openexchange.sessiond.maxSessionPerUser:100

100 Sessions per user should be large enough per default. The question is why could this limit be reached?

Greetings

[mrbscreen]

Ok I found the setting about the lifetime.

# maxiumum value in milliseconds a session is allowed to be kept without
# request.
com.openexchange.sessiond.sessionDefaultLifeTime:3600000

If I interpreted this correct the session should be discarded after one hour. But it seems that this is not done... Because I cant believe that the login is done more than one hundred per hour.

Greetings

[Martin Heiland]

Hi,

this is not the correct configuration setting, please use:

# maximum number of concurrent sessions, 0 stands for unlimited
com.openexchange.sessiond.maxSession:5000

# maximum number of concurrent sessions per user, a value less than or equal to zero means unlimited
com.openexchange.sessiond.maxSessionPerUser:0

The session handling is a bit more complex than it seems, user sessions will expire about 7-8 hours _inactivity_. Every click at the gui marks them as active. The problem is not that the user has logged some hundred times, as i said this is typically triggered by external clients like webdav.infostore or kontact or sunbird...

Greetings

[mrbscreen]

Ok. I changed the settings. It works now. Thank you very much!

[gaggaman]

We see the same here. One user is using the web interface only and gets the Max Session Size error. The settings in sessiond.properties are

com.openexchange.sessiond.maxSession:0
com.openexchange.sessiond.maxSessionPerUser:100

It is the default sessiond.properties file. I am hesitating to remove the maxSessionPerUser Limit as we'll have quite a number of users on the system when it goes into production. Am I right that removing the maxSessionPerUser Limit would mean that if one client goes berserk, the whole system will be screwed?

Anyways, the error says "Max Session Size error". Are you shure this refers to the Number of sessions?

Is it somehow possible to monitor the number of sessions a user has currently open?

We are running the latest and greatest build 6.8.1-6824

Thanks!
(Gerald)

[gaggaman]

Here is an excerpt from the log file. I want to emphasize The user is using the web interface only!!

As you can see, one new session is created every minute!

Jul 6, 2009 4:17:56 PM com.openexchange.authentication.imap.impl.IMAPAuth entication handleLoginInfo
INFO: Imap authentication for user xxx.xxx successful on host xxx.xxx.xx:143
Jul 6, 2009 4:17:56 PM com.openexchange.sessiond.impl.SessionHandler addSession
INFO: Session created. ID: 2fd36dce71e94434b93806da1182f8c6, Context: 1, User: 12
Jul 6, 2009 4:18:57 PM com.openexchange.authentication.imap.impl.IMAPAuth entication handleLoginInfo
INFO: Imap authentication for user xxx.xxx successful on host xxx.xxx.xx:143
Jul 6, 2009 4:18:57 PM com.openexchange.sessiond.impl.SessionHandler addSession
INFO: Session created. ID: 9bac55461d4544c881601b305514fb36, Context: 1, User: 12
Jul 6, 2009 4:19:57 PM com.openexchange.authentication.imap.impl.IMAPAuth entication handleLoginInfo
INFO: Imap authentication for user xxx.xxx successful on host xxx.xxx.xx:143
Jul 6, 2009 4:19:57 PM com.openexchange.sessiond.impl.SessionHandler addSession
INFO: Session created. ID: 8050b6c59b884ca0b0327d70aaa8d5e0, Context: 1, User: 12
Jul 6, 2009 4:20:57 PM com.openexchange.authentication.imap.impl.IMAPAuth entication handleLoginInfo
INFO: Imap authentication for user xxx.xxx successful on host xxx.xxx.xx:143
Jul 6, 2009 4:20:57 PM com.openexchange.sessiond.impl.SessionHandler addSession
INFO: Session created. ID: f4f06bdda79f4fb0955581ef3ec11d60, Context: 1, User: 12
Jul 6, 2009 4:21:57 PM com.openexchange.authentication.imap.impl.IMAPAuth entication handleLoginInfo
INFO: Imap authentication for user xxx.xxx successful on host xxx.xxx.xx:143
Jul 6, 2009 4:21:57 PM com.openexchange.sessiond.impl.SessionHandler addSession
INFO: Session created. ID: 8ce2b3d6d9494700a835c6c0276d095e, Context: 1, User: 12
Jul 6, 2009 4:22:58 PM com.openexchange.authentication.imap.impl.IMAPAuth entication handleLoginInfo
INFO: Imap authentication for user xxx.xxx successful on host xxx.xxx.xx:143
Jul 6, 2009 4:22:58 PM com.openexchange.sessiond.impl.SessionHandler addSession
INFO: Session created. ID: 6607eb265a624771af29d9638cbc14d9, Context: 1, User: 12
Jul 6, 2009 4:23:58 PM com.openexchange.authentication.imap.impl.IMAPAuth entication handleLoginInfo
INFO: Imap authentication for user xxx.xxx successful on host xxx.xxx.xx:143
Jul 6, 2009 4:23:58 PM com.openexchange.sessiond.impl.SessionHandler addSession
INFO: Session created. ID: 7c6fca7abcf34b4db3c75a36ec93a7c9, Context: 1, User: 12
Jul 6, 2009 4:24:58 PM com.openexchange.authentication.imap.impl.IMAPAuth entication handleLoginInfo
INFO: Imap authentication for user xxx.xxx successful on host xxx.xxx.xx:143
Jul 6, 2009 4:24:58 PM com.openexchange.sessiond.impl.SessionHandler addSession
INFO: Session created. ID: c66383146a164b7fb5a78af51cf574f1, Context: 1, User: 12
Jul 6, 2009 4:25:58 PM com.openexchange.authentication.imap.impl.IMAPAuth entication handleLoginInfo
INFO: Imap authentication for user xxx.xxx successful on host xxx.xxx.xx:143
Jul 6, 2009 4:25:58 PM com.openexchange.sessiond.impl.SessionHandler addSession
INFO: Session created. ID: 149f147603a3458a9080e7b17bbe3b20, Context: 1, User: 12

[Martin Heiland]

Hi,

regarding to you first questions:

* Having many open sessions will not entirely screw the system but every session means some memory which is reserved. Typical servers can take some tenthousand sessions so you won't have problems with typical usage.

* The session "size" is maybe not the 100% perfect word, but yeah the number of sessions is meant here. Monitoring sessions can be done using the command line tool "showruntimestats -x | grep Session" which counts the sessions at the whole system, not user specific sorry.

* The one-session-per-minute problem sounds pretty strange, what client does the user use? Is there some network magic going on? I see that the user never drops a session but a new one is created. Could it be that there are some browser settings/extensions dropping sessions etc? Does that occur only for this single user or are there more users causing this? Could you please provide a network capture between the user and the OX server, gonna check what kinds of connections are opened and why.

Greetings

[gaggaman]

Hello Martin,

It happened with two different PCs, both running Firefox 3.0.11. There is nothing special in the network. The ox server is behind a firewall, but the firewall log shows that there was nothing rejected by the firewall at that time.

We have modified the apache vhost to work on https:// instead of http://, thus tracking the traffic between the client and the ox server is somewhat hard.

[Martin Heiland]

Hi,

you could install Firebug (http://getfirebug.com/) on that machines and enable the console. Every request to the OX server will be logged there. New sessions are created when requesting /ajax/login, this request should also show up at the apache access.log file.

Greetings

[gaggaman]

Ok, I'll try to catch it as soon as it appears again.

[Martin Heiland]

This has been identified as a problem with two gateways where the client ip address switches.

[gaggaman]

sorry, but I have to disagree. This one definitely also happened on a plain DSL connection.

[BastianPoe]

Hey guys,


I am expierencing the same problem. We have OX 6.12.0 Rev3 installed and I am using the OXtender for Outlook. Today I restarted my Outlook and now the OXtender reports a server error. The WebIF says:

Fehlermeldung: Max. Session-Größe für Benutzer 2563 im Kontext 1 überstiegen (SES-0007, -1741848196-13959)

The number of sessions is unlimited and the number of sessions per user is limited to 100. This problem started to occur yesterday and we restartet OX. Now (not even 24h later) we do have the same problem again.

What can I do to avoid that?


Regards,

Bastian