Help me understand apache ab

Question

I did a few google searches, but did not find an explanation of how it actually performs stress tests.

As far as I understand, concurrency means the simultaneous number of connections.

ab probably starts the given number of connections "c" at the same time and holds the next waves until all requests are completed. I'm right?

Given a larger number of requests, ab can execute requests / concurrency number of waves. Is it correct?

In the light of these statements, what do these numbers mean:

• Time / Request
• Time / request for all concurrent requests
• Requests / second

(Basically, the second dimension means that ab will send a new request at each concurrency level immediately after the previous one).

So I'm confused. Thanks in advance.

Answer 1

I could not find anything to support this, but I am sure that ab keeps track of simultaneous requests and keeps a constant number of requests active, rather than sending requests in waves. For example, if you specify 50 concurrent connections, rather than waiting for the first 50 requests to complete and then send another 50, ab will continue to send a new request immediately after the request is completed, so there will always be 50 active connections.