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=1A7KADKCHTB1IJS3Z5CR16OZM4VLSQ&hitId=1NAV09D0NWNU2X87QR3I6RXXG0ER8N&workerId=A37YC0D90LZF2M&turkSubmitTo=https%3A%2F%2Fwww.mturk.com [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=1A9FV5YBGVV54NALMIRILFKHPT1O3I&hitId=1G15BSUI1DBLMZPV54KGZFTE6JM0Z3&workerId=A3I5DLZHYT46GS&turkSubmitTo=https%3A%2F%2Fwww.mturk.com [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.