MongoDB Nginx Module

Server NGINX
1

Hi Nginx Mailing List,

I’m in the process of creating a nginx module that serves files from a
file
system within mongoDB.

Code is here: http://github.com/mdirolf/nginx-gridfs

Basically we embed our C-driver into the module and talk to mongoDB that
way.
When the handler is called, it retrieves a file chunk by chunk from
mongoDB
and serves it.

I would be very grateful if someone would be able to clear up a few
things
for me, as I still haven’t fully wrapped my head around nginx’s
internals…

Do I save anything by calling ngx_http_output_filter() for each chunk of
data.
If the call to mongoDB blocks the worker process, would it be just the
same
to call ngx_http_output_filter() once for the whole file?
Might there be a faster way to accomplish this task?

Thanks in advanced!

Christopher

2

Hey thanks so much for your response!

I’ll look into that upstream facility. Looks like thats is exactly what
I
need.

Thanks again!
Christopher

3

On Tue, Jul 13, 2010 at 5:22 AM, Christopher Triolo
[email protected] wrote:

I’m in the process of creating a nginx module that serves files from a file
system within mongoDB.
Code is here: GitHub - mdirolf/nginx-gridfs: Nginx module for serving files from MongoDB's GridFS
Basically we embed our C-driver into the module and talk to mongoDB that
way.

By looking at the source code, it seems to me that it blocks on I/O.
Sigh.

When the handler is called, it retrieves a file chunk by chunk from mongoDB
and serves it.

Is it possible to make it non-blocking? Like those using the
ngx_http_upstream facility?

I would be very grateful if someone would be able to clear up a few things
for me, as I still haven’t fully wrapped my head around nginx’s internals…
Do I save anything by calling ngx_http_output_filter() for each chunk of
data.

Actually, it usually makes things slower if the chunk is too small
(more invocations of the output filter chain and more writev
syscalls). We observed a significant performance difference in our
mysql driver module ngx_drizzle :wink:

If the call to mongoDB blocks the worker process, would it be just the same
to call ngx_http_output_filter() once for the whole file?

Not really :slight_smile:

Cheers,
-agentzh