Thanks Willy, The information that you gave me was very helpful. I checked your suggestions and you are right. I made the client upload files from another place and it seems to work quite nicely. So I guess I have to figure out if my internet provider is making the caching/proxy, or my hosting provider is doing this.
Cheers for the great product that you've made and the helpful mailing list. Regards, Galfy On Tue, Jun 21, 2011 at 10:29 PM, Willy Tarreau <w...@1wt.eu> wrote: > On Tue, Jun 21, 2011 at 04:23:52PM +0200, Galfy Pundee wrote: >> Hi all, >> At the moment I am evaluating haproxy as a reverse proxy. Everything >> seems to work great except one thing and I do not know where is the >> problem. The situations in which I get the problem is the following: >> 1. client uploads big file to the haproxy >> 2. all incoming data seems to be sent from the client but the backend >> is taking quite some time to save the data to the hard disk. >> 3. meanwhile the client reports time out >> 4. There is nothing sent from the client to the server, but the >> backend seems to continue to write the file until it writes down all >> the bytes. >> >> As a result all uploads of big files are reported from the client as >> failed, even though they are stored with a delay. How can I make the >> client aware about this fact? Why is this happening? Can it be that >> the haproxy is getting the data very fast, but the backend cannot >> store it so fast? Any suggestions or similar experiences? > > This cannot be the case because haproxy's buffers are relatively small > size (16 kB by default), so it cannot hold all of the request. However > what you describe is common when there is a client-side anti-virus which > parses POST requests. What happens is exactly what you're describing, > the client sends everything very fast to the local gateway, and waits > for a long time while the data are uploaded over a slow link, then > finally times out. > > Do you know if there is any such thing on the client side ? Alternatively > it is possible that socket buffers on the client are far too large and are > able to hold the whole request at once without the client application being > aware of this. This is less common because what you describe suggests that > the amount of data is huge, but still this is a possible scenario that I've > observed with a USB 3G key with huge buffers. > > Ideally you should put a tcpdump on the client side and in front of haproxy > to see what's happening. But if you're facing a proxy which buffers > everything before passing on the request, I see no easy solution to the > problem. > > Regards, > Willy > >
