转载，原文出处：https://blog.csdn.net/wawa8899/article/details/54408060
环境：CentOS6.7 + Apache2.4 + Django1.8
背景：早前对apache日志按天进行了分割，每天日志文件大小很稳定。最近发现apache错误日志文件巨大，每天都打印很多很多行[wsgi:error]
[Mon Dec 26 08:24:58.245875 2016] [wsgi:error] [pid 24768:tid 140371390662400] 17
[Mon Dec 26 08:24:58.245891 2016] [wsgi:error] [pid 24768:tid 140371390662400] 16
[Mon Dec 26 08:24:58.245906 2016] [wsgi:error] [pid 24768:tid 140371390662400] 15
[Mon Dec 26 08:24:58.245922 2016] [wsgi:error] [pid 24768:tid 140371390662400] 14
[Mon Dec 26 08:24:58.245937 2016] [wsgi:error] [pid 24768:tid 140371390662400] 13
[Mon Dec 26 08:24:58.245953 2016] [wsgi:error] [pid 24768:tid 140371390662400] 12
[Mon Dec 26 08:24:58.245969 2016] [wsgi:error] [pid 24768:tid 140371390662400] 11
[Mon Dec 26 08:24:58.245984 2016] [wsgi:error] [pid 24768:tid 140371390662400] 10
[Mon Dec 26 08:24:58.246000 2016] [wsgi:error] [pid 24768:tid 140371390662400] 9
[Mon Dec 26 08:24:58.246015 2016] [wsgi:error] [pid 24768:tid 140371390662400] 8
[Mon Dec 26 08:24:58.246031 2016] [wsgi:error] [pid 24768:tid 140371390662400] 7
[Mon Dec 26 08:24:58.246046 2016] [wsgi:error] [pid 24768:tid 140371390662400] 6
[Mon Dec 26 08:24:58.246061 2016] [wsgi:error] [pid 24768:tid 140371390662400] 5
观察了很久，发现每一行错误日志最后的内容都是项目中打印的字段，网上查了很久，最终发现这些wsgi:error是Django代码中的print语句引起的，注释掉所有的print语句后问题解决。
参考文献：
http://blog.dscpl.com.au/2009/04/wsgi-and-printing-to-standard-output.html
http://serverfault.com/questions/239614/wsgi-and-python-print-statements
