The solution: I switched to Flask. And the problems dissipated completely, without modifying any configuration of the web server.
I would not, and will not use web2py for any application that is mission critical. For personal sites, or quick projects that I know won't receive that much attention, web2py is fine. For quickly prototyping something, web2py excels. For stability, reliability, and scalability, use Flask or Django. The DAL is great though, nothing quite like it, thats why I am working on a Flask-DAL extension, and I am working to re-write parts of the DAL and strip out the web2py cohesion (such as SQLFORM validators). Using the DAL inside of flask works fine, and I do not run into these errors. This means that the DAL is not the cause of these errors, but web2py core code. Most likely in dealing with pages that have forms is where these errors arise. Web2py core is messy, and it ignores the wsgi specification for the most part. I am sure that these errors arise from the fact that web2py uses execfile in many places over and over again, which is a discouraged practice among the python community, and you see why now. -- Thadeus On Tue, Jul 20, 2010 at 4:17 PM, Michael Toomim <too...@gmail.com> wrote: > Thank you for the clarification. > > My wsgi.conf has default values, so I have not set maximum-requests. > Perhaps there are settings there I should look into? > > I still have free memory, so perhaps there is not a memory leak > issue. I'm also not sure how one would get memory leaks in web2py, > since isn't the environment wiped clean with each request? > > This looks similar to the issue here: > > http://groups.google.com/group/web2py/browse_thread/thread/49a7ecabf4910bcc/b6fac1806ffebcd1?lnk=gst&q=ioerror#b6fac1806ffebcd1 > Was there any resolution? > > I use logging by having the following file in models/0_log.py: > > import logging > def get_log(): > try: > f = open(logging.handlers[0].baseFilename, 'r') > c = f.readlines() > f.close() > return {'log':TABLE(*[TR(str(item)) for item in c])} > except: > return () > > > # This model file defines some magic to implement app_wide_log. > def _init_log(): # Does not work on GAE > import os,logging,logging.handlers > logger = logging.getLogger(request.application) > logger.setLevel(logging.DEBUG) > handler = logging.handlers.RotatingFileHandler( > os.path.join( # so that it can be served as http:// > .../yourapp/static/applog.txt > request.folder,'static','applog.txt'),'a',1024*1024,1) > handler.setLevel(logging.DEBUG) > handler.setFormatter(logging.Formatter("%(asctime)s %(levelname)s % > (filename)s:%(lineno)d %(funcName)s(): %(message)s")) > logger.addHandler(handler) > return logger > > logging = > cache.ram('app_wide_log',lambda:_init_log(),time_expire=None) > > > On Jul 20, 2:03 am, mdipierro <mdipie...@cs.depaul.edu> wrote: > > Thanks for the clarification. > > > > @Michael, do you use the logging module? How? > > > > On Jul 20, 4:00 am, Graham Dumpleton <graham.dumple...@gmail.com> > > wrote: > > > > > > > > > On Jul 20, 5:17 pm, mdipierro <mdipie...@cs.depaul.edu> wrote: > > > > > > The problem with IOError, I can understand. As Graham says, if the > > > > client closes the connection before the server responds or if the > > > > server timesout the socket is closed and apache logs the IOError. > > > > > That isn't what I said. If you see that message when using daemon > > > mode, the Apache server process that is proxying to the daemon process > > > is crashing. This is different to the HTTP client closing the > > > connection. You would only see that message if HTTP client closed > > > connection if using embedded mode. > > > > > I know they are using daemon mode as that is the only situation where > > > they could also see the message about premature end of script headers. > > > > > > What I really do not understand is why some requests are handled by > > > > multiple threads. web2py is agnostic to this (unless you use Rocket > > > > which you do not). web2py only provides a wsgi application which is > > > > executed - per thread - by the web server. It is the web server (in > > > > your case apache) that spans the thread, maps requests to threads, > > > > calls the web2py wsgi application for each of them. > > > > > > If this is happening it is a problem with apache or with mod_wsgi. > > > > > More likely the problem is that they are registering the logging > > > module from multiple places and that is why logging is displayed more > > > than once. They should log the thread ID as well as that would confirm > > > whether actually from the same thread where logging module handler has > > > been registered multiple times. > > > > > Multiple registrations of logging handler could occur if it isn't done > > > in a thread safe why, ie., so as to avoid multiple threads doing it at > > > the same time. > > > > > Graham > > > > > > Can > > > > you tell us more about the version of ubuntu, apache and mod_wsgi > that > > > > you are using? Any additional information will be very useful. > > > > > > Massimo > > > > > > On Jul 19, 9:01 pm, Michael Toomim <too...@gmail.com> wrote: > > > > > > > I'm getting errors like these in my apache error logs: > > > > > > > [Mon Jul 19 18:55:20 2010] [error] [client 65.35.93.74] Premature > end > > > > > of script headers: wsgihandler.py, referer: > http://yuno.us/init/hits/hit?assignmentId=1A7KADKCHTB1IJS3Z5CR16OZM4V... > > > > > [Mon Jul 19 18:55:20 2010] [error] [client 143.166.226.43] > Premature > > > > > end of script headers: wsgihandler.py, referer: > http://yuno.us/init/hits/hit?assignmentId=1A9FV5YBGVV54NALMIRILFKHPT1... > > > > > [Mon Jul 19 18:55:50 2010] [error] [client 117.204.99.178] mod_wsgi > > > > > (pid=7730): Exception occurred processing WSGI script > '/home/toomim/ > > > > > projects/utility/web2py/wsgihandler.py'. > > > > > [Mon Jul 19 18:55:50 2010] [error] [client 117.201.42.84] mod_wsgi > > > > > (pid=7730): Exception occurred processing WSGI script > '/home/toomim/ > > > > > projects/utility/web2py/wsgihandler.py'. > > > > > [Mon Jul 19 18:55:50 2010] [error] [client 117.201.42.84] mod_wsgi > > > > > (pid=7730): Exception occurred processing WSGI script > '/home/toomim/ > > > > > projects/utility/web2py/wsgihandler.py'. > > > > > [Mon Jul 19 18:55:50 2010] [error] [client 117.201.42.84] IOError: > > > > > failed to write data > > > > > [Mon Jul 19 18:55:50 2010] [error] [client 117.201.42.84] mod_wsgi > > > > > (pid=7730): Exception occurred processing WSGI script > '/home/toomim/ > > > > > projects/utility/web2py/wsgihandler.py'. > > > > > [Mon Jul 19 18:55:50 2010] [error] [client 117.201.42.84] IOError: > > > > > failed to write data > > > > > [Mon Jul 19 18:55:50 2010] [error] [client 117.201.42.84] mod_wsgi > > > > > (pid=7730): Exception occurred processing WSGI script > '/home/toomim/ > > > > > projects/utility/web2py/wsgihandler.py'. > > > > > [Mon Jul 19 18:55:50 2010] [error] [client 117.201.42.84] IOError: > > > > > failed to write data > > > > > [Mon Jul 19 18:55:50 2010] [error] [client 117.201.42.84] mod_wsgi > > > > > (pid=7730): Exception occurred processing WSGI script > '/home/toomim/ > > > > > projects/utility/web2py/wsgihandler.py'. > > > > > [Mon Jul 19 18:55:50 2010] [error] [client 117.201.42.84] IOError: > > > > > failed to write data > > > > > > > My web app gets about 7 requests per second. At first, things work > > > > > fine. Then after a while it seems like every request gets handled > by > > > > > MULTIPLE threads, because my logging.debug() statements print > multiple > > > > > copies of each message and it seems my database gets multiple > entries. > > > > > And I get these errors in the apache logs (with LogLevel debug). > > > > > > > Any idea what to do? Where to look? I'm on ubuntu. >
