Nginx as a proxy with Blocking operations

[abhi2528]

Hi All,

We have an existing TCP/TLS based server application 'A' in production.
Around 10K users can connect to this application. We now have a requirement
as follows:

1). Intercept the traffic between Client and A 
2). 'Inspect' the packet for a certain logic 
3). If the packet matches, call a processing logic (THIS IS A BLOCKING
OPERATION AS UNFORTUNATELY THE PROCESSING REQUIRES SOME SORT OF HUMAN
INTERVENTION AND MAY TAKE BETWEEN 30 - 60 Seconds). The frequency for match
might be just 5-10% of traffic 
4). Based on the result of processing either send the packet as is to 'A' or
modify the packet content and then send to 'A'.

I understand that this is most definitely an ideal scenario as the blocking
operation is involved, but the requirements are pretty stringent.

I just wanted to understand if Nginx can help me in this context. Does Nginx
support such blocking operations? Basically the idea is that if one request
matches for the Blocking Operation processing, the other parallel/concurrent
requests should not be BLOCKED(or wait). In layman terms a scenario where
every request has an independent thread and processing.

Can anyone suggest a solution for this problem. 

Again I acknowledge that this might not be the best way forward but somehow
we are constrained.

Looking forward to some great advice.

Many Thanks,
Abhi

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,256463,256463#msg-256463