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crash of sage notebook server at login?

asked 2014-10-23 08:58:39 -0500

msage gravatar image

updated 2014-10-23 09:00:27 -0500

Hello, we have the problem, that our sage otebook server crashes from time to time. We use Version 6.3.

This happens at a time when about 10 or 12 students login at about the same time. When this happens, the webinterface (Apache virtual Host) shows "Service Temporarily unavailable" in the website. The complete server has to be rebooted.

Log file of the last crash is attached, the server was rebooted after the crash, which is also shown in the logfile. So the last error is, that a user cannot be found.

I tried to replicate the error. What I found is a weird behaviour of the login screen when given wrong usernames:

If the username is numeric: 12121312312 -> "Error: Username is not in the system " is shown in the login screen

If the username is alphanumeric and begins with a number: 534534534gfdgdfg -> "Error: Username is not in the system " is shown in the login screen

If the username is alphanumeric and begins with a char and is only 2 char long: bb or b3 -> "Error: Username is not in the system " is shown in the login screen

If the username is alphanumeric and begins with a char and is longer than 2 chars: gfdgdfg312312 -> I get a blank screen in the Browser (maybe ERROR 500?) and an entry in the log file,

And I think this may leed to a complete crash of the notebook server from time to time, too.

This posting shows the same problem: https://www.mail-archive.com/sage-dev...

Does anyone have a tip, solution or the same problem?

2014-10-23 12:07:32+0200 [-] WSGI application error
        Traceback (most recent call last):
          File "/opt/sage6.3/local/lib/python2.7/site-packages/Twisted-13.2.0-py2.7-linux-x86_64.egg/twisted/python/threadpool.py", line 212, in _worker
            o = self.q.get()
          File "/opt/sage6.3/local/lib/python2.7/site-packages/Twisted-13.2.0-py2.7-linux-x86_64.egg/twisted/python/context.py", line 118, in callWithContext
            return self.currentContext().callWithContext(ctx, func, *args, **kw)
          File "/opt/sage6.3/local/lib/python2.7/site-packages/Twisted-13.2.0-py2.7-linux-x86_64.egg/twisted/python/context.py", line 83, in callWithContext
            self.contexts.pop()
          File "/opt/sage6.3/local/lib/python2.7/site-packages/Twisted-13.2.0-py2.7-linux-x86_64.egg/twisted/web/wsgi.py", line 340, in run
            self.started = True
        --- <exception caught here> ---
  File "/opt/sage6.3/local/lib/python2.7/site-packages/Twisted-13.2.0-py2.7-linux-x86_64.egg/twisted/web/wsgi.py", line 315, in run
            appIterator = self.application(self.environ, self.startResponse)
          File "/opt/sage6.3/local/lib/python2.7/site-packages/Flask-0.10.1-py2.7.egg/flask/app.py", line 1836, in __call__
            return self.wsgi_app(environ, start_response)
          File "/opt/sage6.3/local/lib/python2.7/site-packages/Flask-0.10.1-py2.7.egg/flask/app.py", line 1820, in wsgi_app
            response = self.make_response(self.handle_exception(e))
          File "/opt/sage6.3/local/lib/python2.7/site-packages/Flask-0.10.1-py2.7.egg/flask/app.py", line 1403, in handle_exception
            reraise(exc_type, exc_value, tb)
          File "/opt/sage6.3/local/lib/python2.7 ...
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Comments

I posted a link to this question on [sage-notebook](https://groups.google.com/d/topic/sage-notebook/6kdImFgVMw8), hoping that will get some expert's attention.

slelievre gravatar imageslelievre ( 2014-10-23 11:32:07 -0500 )edit

I just can't replicate this behavior, especially with regard to the > 2 chars long bit. I just always get the same message.

kcrisman gravatar imagekcrisman ( 2014-10-27 08:49:15 -0500 )edit

hm, anyone other can replicate it? maybe it happens at opening worksheets and not right at the login?

msage gravatar imagemsage ( 2014-10-30 01:37:06 -0500 )edit

The crashing almost certainly happens at opening worksheets, that has been my experience in the past. But again, you really seem to have plenty of RAM, so this surprises me.

kcrisman gravatar imagekcrisman ( 2014-10-30 07:15:16 -0500 )edit

3 answers

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answered 2014-10-23 14:14:05 -0500

kcrisman gravatar image

I don't have a lot of ideas here; usually what makes a Sage notebook server crash is not having enough memory, though I have never actually been watching the terminal when this all happened since I was not the admin. And usually I haven't seen these errors - it's more of hangs.

But my money is on this nonetheless. See here for some general rules of thumb. I found that it was a fairly linear scaling in terms of memory needed per open session, probably somewhere around 100 MB per person (within a factor of two, anyway). So having a 1 GB memory is not sufficient for most medium-sized classes.

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answered 2014-10-27 03:16:49 -0500

cjsh gravatar image

hello!

why your 6.3 version not let all people sign up? and no email to connection.....

or you can amalgamate with sagenb.org

I find three sagenb 6.3,but only sign in,all no sign up button

Solidarity is power , cohesion is hope!

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No it has nothing to do with signin up. It happens at the login

msage gravatar imagemsage ( 2014-10-30 01:34:57 -0500 )edit
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answered 2014-10-24 00:18:58 -0500

msage gravatar image

I have installed the server according to the tutorial in the wiki.

I don't think it is a memory problem.

The server has 9 GB of RAM and 4 GB free disk space:

df -h
/dev/sda1        19G     15G  4,0G   79% /

This is in idle mode:

top - 07:11:33 up 19:00,  4 users,  load average: 0.31, 0.19, 0.10
Tasks: 104 total,   1 running, 103 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.3%us,  0.0%sy,  0.0%ni, 98.7%id,  1.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   8991808k total,  2252904k used,  6738904k free,   237624k buffers
Swap:  1046524k total,        0k used,  1046524k free,  1002044k cached

This is while evaluating a worksheet with many graphic outputs:

top - 07:12:24 up 19:01,  4 users,  load average: 0.50, 0.24, 0.13
Tasks: 104 total,   1 running, 103 sleeping,   0 stopped,   0 zombie
Cpu(s):  9.7%us,  0.7%sy,  0.0%ni, 86.6%id,  3.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   8991808k total,  2253868k used,  6737940k free,   237672k buffers
Swap:  1046524k total,        0k used,  1046524k free,  1002236k cached
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Comments

I thought I commented on this... using less than 1 MB for a worksheet seems suspicious to me, but maybe it's okay. But anyway the real question is what happens with 10-12 users. However, you are right that 4 GB should suffice for your size.

kcrisman gravatar imagekcrisman ( 2014-10-27 08:45:31 -0500 )edit

it's 9GB of RAM. 4 GB is harddisk, that should be way enough=

msage gravatar imagemsage ( 2014-10-30 01:36:20 -0500 )edit

Yes. I'm really sorry I can't replicate the login issue for you.

kcrisman gravatar imagekcrisman ( 2014-10-30 07:14:20 -0500 )edit

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Asked: 2014-10-23 08:58:39 -0500

Seen: 325 times

Last updated: Oct 27 '14