Nginx – Clients not completing download of large file from NGINX – network issue

How do you arrive at your 0.04s rendering time? You might want to want to remove PHP from the equation entirely an benchmark against static files only.

There are a few things you can do to improve your configuration, though. First of all, your gzip compression level can be increased quite safely, the CPU impact is minimal but you can gain a smaller data size by increasing it to 5. I found increasing it further than that rarely yields any benefit.

You can also quite easily increase your keep-alive timeout, the default value is 75. This probably won't help raw throughput much but if a client's browser allows it then it will seem snappier.

After that you might want to use an open-file cache. I use the following configuration:

open_file_cache max=5000 inactive=20s;
open_file_cache_valid    30s;
open_file_cache_min_uses 2;
open_file_cache_errors   on;

You can find the documentation on that here: http://wiki.nginx.org/NginxHttpCoreModule#open_file_cache

Since you have no buffers specified it might be that the buffers aren't large enough and thus the response is stored on temporarily on the disk. You can see if iostat 1 shows a large iowait time.

The interesting buffers are

• client_body_buffer_size
• output_buffer

The client body buffer is documented here: http://wiki.nginx.org/NginxHttpCoreModule#client_body_buffer_size

The output buffer is not documented in the wiki but it takes two arguments, the first one is the amount of buffers and the second one is the size of each of them. The output buffer is primarily used when sendfile is off or if you gzip data before sending it to the user, so you'll definitely want to make sure the data fits.

Try this:

1. Setup the virtualbox to use 2 adapters:
   • The first adapter is set to NAT (that will give you the internet connection).
   • The second adapter is set to host only.
2. Start the virtual machine and assign a static IP for the second adapter in Ubuntu (for instance 192.168.56.56). The host Windows will have 192.168.56.1 as IP for the internal network (VirtualBox Host-Only Network is the name in network connections in Windows). What this will give you is being able to access the apache server on ubuntu, from windows, by going to 192.168.56.56. Also, Ubuntu will have internet access, since the first adapter (set to NAT) will take care of that.
3. Now, to make the connection available both ways (accessing the windows host from the ubuntu guest) there's still one more step to be performed. Windows will automatically add the virtualbox host-only network to the list of public networks and that cannot be changed. This entails that the firewall will prevent proper access.
4. To overcome this and not make any security breaches in your setup:
   • go to the windows firewall section, in control panel,
   • click on advanced settings. In the page that pops up,
   • click on inbound rules (left column), then on new rule (right column). Chose custom rule, set the rule to allow all programs, and any protocol. For the scope, add in the first box (local IP addresses) 192.168.56.1, and in the second box (remote IP) 192.168.56.56. Click next, select allow the connection, next, check all profiles, next, give it a name and save.

That's it, now you have 2 way communication, with apache/any other service available as well as internet. The final step is to setup a share. Do not use the shared folders feature in virtualbox, it's quite buggy especially with windows 7 (and 64 bit). Instead use samba shares - fast and efficient.

Follow this link for how to set that up: https://wiki.ubuntu.com/MountWindowsSharesPermanently