Hi,
I'd really like to see similar queue mechanism in limit_conn such as in limit_req_rate with burst + delay option. What it really does is wait before throwing an 503 error before queue reaches certain number (allowed burst). That behavior would be more than welcome since not always reaching max conn limit is so bad. If it's 1 connection for a fraction of second ant guest gets 503 he can go away and never come back.
I'm aware of Ey-ballancer module, but above seams much simpler and i think it could be ported from limit_req_rate easyly.
Regards,
Meto