# 回复: Re: about "large file" and "resume download" on reverse proxy mode

**URL:** <https://www.ruby-forum.com/t/re-about-large-file-and-resume-download-on-reverse-proxy-mode/209526>\
**Category:** NGINX\
**Created:** [July 15, 2011, 6:19pm UTC](https://www.ruby-forum.com/t/re-about-large-file-and-resume-download-on-reverse-proxy-mode/209526 "2011-07-15T18:19:32Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\
**Post date:** [July 15, 2011, 6:19pm UTC](https://www.ruby-forum.com/t/re-about-large-file-and-resume-download-on-reverse-proxy-mode/209526/1 "2011-07-15T18:19:32Z")

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Thank your reply.  
But it is not for my question.  
When the item isn’t cached(If it is very large over 1G,it would take a  
long time to be cached),many normal users download it,then the proxy  
server would download the item from upstream server with many  
connections.

I seach the forum,found the same question:

> **[Re: proxy\_cache](https://forum.nginx.org/read.php?2,193353,193633#msg-193633)**
>
> Hi Is there a way to know if a file has been cached/is currently being downloaded to cache without requesting the file? I.e. can I query the cache table somehow? I am trying to stop new files being written multiple times to disk when they are...

Currently, there is no good way to handle this. Solution is  
usually called “busy locks” (search list archives for details),  
but it’s not ready yet.

Maxim D.

I am waiting for later version.  
2011-07-16

chinix

发件人: António P. P. Almeida [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
发送时间: 2011-07-15 20:49  
主 题: Re: about “large file” and “resume download” on reverse proxy mode  
收件人: removed\_email\_address@domain.invalid

On 15 Jul 2011 06h39 WEST, removed\_email\_address@domain.invalid wrote:

> Dear list, I am testing nginx with reverse proxy mode. I  
> found that nginx download the file from upstream server to  
> proxy\_temp\_path when I download a file from the reverse proxy  
> server,if I stop and re-download,the nginx will download the file  
> from upstream server again,and so on. The problem is when a large  
> file on a site,someone could launch malicious multi-threaded  
> connections to attack the reverse proxy server and upstream server.  
> any configuration to limit it?

See [Module ngx\_http\_limit\_req\_module](http://wiki.nginx.org/HttpLimitReqModule) and  
[http://wiki.nginx.org/HttpLimitZoneModule](http://wiki.nginx.org/HttpLimitZoneModule).

— appa

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