Definition of Connect, Processing, Waiting in apache bench

Question

When I run apache bench I get results like:

Command: abs.exe -v 3 -n 10 -c 1 https://mysite Connection Times (ms)               min  mean[+/-sd] median   max Connect:      203  213   8.1    219     219 Processing:    78  177  88.1    172     359 Waiting:       78  169  84.6    156     344 Total:        281  389  86.7    391     564 

I can't seem to find the definition of Connect, Processing and Waiting. What do those numbers mean?

Answer 1

By looking at the source code we find these timing points:

apr_time_t start,           /* Start of connection */            connect,         /* Connected, start writing */            endwrite,        /* Request written */            beginread,       /* First byte of input */            done;            /* Connection closed */ 

And when request is done some timings are stored as:

        s->starttime = c->start;         s->ctime     = ap_max(0, c->connect - c->start);         s->time      = ap_max(0, c->done - c->start);         s->waittime  = ap_max(0, c->beginread - c->endwrite); 

And the 'Processing time' is later calculated as

s->time - s->ctime; 

So if we translate this to a timeline:

t1: Start of connection t2: Connected, start writing t3: Request written t4: First byte of input t5: Connection closed 

Then the definitions would be:

Connect:      t1-t2   Most typically the network latency Processing:   t2-t5   Time to receive full response after connection was opened Waiting:      t3-t4   Time-to-first-byte after the request was sent Total time:   t1-t5