Will enabling `mod_status` in apache slow my app down?

Question

If I wanted to to monitor response time of my requests should I use Apache's mod_status or should I use Passenger's passenger-status monitoring tools?

My concern is that enabling mod_status will slow my apps down, but I don't have anyway to compare since I need to run mod_status to benchmark the performance.

By the way Passenger's passenger-status only gives me some trivial info like so:

----------- General information -----------
max      = 6
count    = 0
active   = 0
inactive = 0
Waiting on global queue: 0

----------- Domains -----------
...

Answer 1

I don't believe this should have any impact on Apache's performance.

Pretty much all the module is doing is taking internal state that the server already has — ie it knows how many workers it has spawned, what they're doing and so on — and rendering it to HTML.

Answer 2

Just for your information: I have a apache version 2.2.16 running receiving live traffic (so not a benchmark). No ruby or passenger, but with mod_fastcgi.

At 175req/s the server kept up, at 370 it was running at a load of 8-10.

After disabling the Extended status (but keeping mod_status enabled), the load dropped below 2.

Disabling mod_status completely did not make any difference over disabling Extended (load may already be too low to see a difference now).