I found that there are many lines in my web log, my server is fedora linux.
The lines are "221.8.186.158 - - [03/Apr/2006:16:35:26 +0800] "GET log.cpc.sohu.com:90/?pv.png HTTP/1.0" 200 857 "adsence.sogou.com/index.html?pid=mywebcode&ww=200&dc=3&dir=0&num=6&color=1&charset=gb" "Mozilla/4.0 (compatible; MSIE 6.0; Windows 98)"
61.243.176.38 - - [03/Apr/2006:16:36:11 +0800] "CONNECT tcpconn4.tencent.com:443 HTTP/1.1" 400 310 "-" "-""
These lines continue existing in my log, resulting in a huge size within an hour.
Would you suggest me some ways to solve it. Thank you so much.

It looks like someone is trying to use your setup as a proxy. Have you had a look at http://httpd.apache.org/docs/1.3/mis...html#proxyscan to make sure that your server is configured to prevent this happening successfully? It's possible that the first entry with the 200 response code wasn't successful, but it's worth checking your config anyway.

These lines continue existing in my log, resulting in a huge size within an hour.
Would you suggest me some ways to solve it. Thank you so much.

I think it's more like referer spam. See these posts for some idea's:
http://www.linuxquestions.org/questi...22#post1916122
http://en.wikipedia.org/wiki/Referer_spam

* Please note that any solution, especially those that require you to use any form of IP/range blocking, is inflexible because you may be (inadvertedly) blocking ranges where clients may come from and (will become) unmanageable, because you will build up large lists for what probably are one-off's. Most of all this will not be addressing what you have (request) which should be dealt with by filtering using regexes.

** Now we do understand this is some issue to you, but please do not cross-post in LQ. Crossposting is against the LQ Rules. Cross-posting is considered bad netiquette on your part, a waste of resources on LQ's part and a waste of time for LQ members who take the time to read and answer your questions.
Please do not do that again.