Siege unknown responses

Question

I'm trying to test my server on highload resistance with siege utility:

siege http://my.server.ru/ -d1 -r10 -c100

Siege outputs a lot of messages like this:

HTTP/1.1 200   0.46 secs:   10298 bytes ==> /

but sometimes there are error messages like this:

Error: socket: unable to connect sock.c:220: Connection timed out

or this:

warning: socket: -598608128 select timed out: Connection timed out

There is siege report after testing:

Transactions:                949 hits
Availability:                94.90 %
...
Successful transactions:         949
Failed transactions:              51
Longest transaction:            9.87
Shortest transaction:           0.37

In nginx logs on my server, only 950 messages with code 200 and response that all right.

"GET / HTTP/1.1" 200 10311 "-" "JoeDog/1.00 [en] (X11; I; Siege 2.68)"

Can anyone tell me what this means

Error: socket: unable to connect sock.c:220: Connection timed out
warning: socket: -598608128 select timed out: Connection timed out

and why in my nginx logs I only see responses with code 200?

Answer 1

It probably means your pipe is full and can't handle more connections. You can't make nginx or nginx backends accept more connections if if your pipe is full. Try testing against localhost. You will then be testing the stack rather than the stack and the pipe. It will resemble real load less, but give you an idea what you can handle with the bigger pipe.