Saving notebook fails because of memory error

[asteppke]

While working on a medium sized notebook (6 MB on disk) I got an orange error message bar that autosave failed because of a memory error. The notebook contains a number of matplotlib figures.

In the console of the ipython notebook server the following error message is displayed, here the memory error is attributed to a function in handlers.py:

[E 11:17:51.174 NotebookApp] Unhandled error in API request
    Traceback (most recent call last):
      File "c:\Anaconda3\lib\site-packages\notebook\base\handlers.py", line 436,
 in wrapper
        result = yield gen.maybe_future(method(self, *args, **kwargs))
      File "c:\Anaconda3\lib\site-packages\tornado\gen.py", line 870, in run
        value = future.result()
      File "c:\Anaconda3\lib\site-packages\tornado\concurrent.py", line 215, in
result
        raise_exc_info(self._exc_info)
      File "<string>", line 3, in raise_exc_info
      File "c:\Anaconda3\lib\site-packages\tornado\gen.py", line 230, in wrapper

        yielded = next(result)
      File "c:\Anaconda3\lib\site-packages\notebook\services\contents\handlers.p
y", line 236, in put
        model = self.get_json_body()
      File "c:\Anaconda3\lib\site-packages\notebook\base\handlers.py", line 272,
 in get_json_body
        body = self.request.body.strip().decode(u'utf-8')
    MemoryError
[E 11:17:51.178 NotebookApp] {
      "Accept": "application/json, text/javascript, */*; q=0.01",
      "User-Agent": "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHT
ML, like Gecko) Chrome/45.0.2454.101 Safari/537.36",
      "Content-Length": "6264026",
      "Accept-Language": "en-US,en;q=0.8",
      "X-Requested-With": "XMLHttpRequest",
      "Accept-Encoding": "gzip, deflate, sdch",
      "Origin": "http://localhost:8888",
      "Content-Type": "application/json",
      "Host": "localhost:8888",
      "Referer": "http://localhost:8888/notebooks/Lab%20protocol%20October%20201
5%2C%20SrRuO4.ipynb",
      "Connection": "keep-alive"
    }

I could split the notebook to avoid this but this would be annoying. Restarting the kernel and clearing all outputs helped, with no output I was able to save the notebook again. I am making use of the the %matplotlib notebook feature and have some inline figures and I guess this is related.
How can I avoid hitting this issue in the future?

[minrk]

How much memory is available on your machine when this happens? People consistently save notebooks that are 10-50 MB without memory problems. Perhaps you were running code that ate up all of your memory at the time?

[asteppke]

@minrk I checked the memory usage, the calculations alone are not taking up much space but all the plots are. I had this notebook running for some time and recreated the plots multiple times.

After searching around a bit more I guess the error I get might just be a symptom of issue #7270.

[takluyver]

If there's no more memory available, there's not much we can do. We should try to solve #7270, but I haven't been able to find the cause.