webpagetest.org gives a big red *F *to web sites that do* *not have
KeepAlive enabled. Yet, at least in the CentOS installation of Apache, it is off by default. Why is that? What are the reasons that KeepAlive should be off?
The default in 2.2 is on for KeepAlive.
Redhat's docs (right or wrong) are fairly clear on their rationalization for defaulting to off:
"Note that when the persistent connections are enabled, on a busy server, the number of child processes can increase rapidly and eventually reach the maximum limit, slowing down the server significantly. To reduce the risk, it is recommended that you set |KeepAliveTimeout| to a low number, and monitor the |/var/log/httpd/logs/error_log| log file carefully."
This doesn't mean they are right, but they have been doing it for a while. Here's a thread from back in '07 on the same topic:
http://www.redhat.com/archives/nahant-list/2007-September/msg00105.html I guess the question should be: is Redhat's position on KeepAlives valid? Joe
