A brief test of Apache httpd 2.4.1

I briefly tested the Apache httpd 2.4.1 on ftp.jaist.ac.jp. I tested the worker MPM at first. The server, however, become increasingly slower to return responses not long after it started running. It finally stop returning any response. I gave up using the worker MPM. Then I tested the worker MPM. It consumed more memory and CPU than the version 2.2.22.

I measured the following values an hour after the servers started running.

Version	2.2.22	2.4.1
Connections	5029	3697
Requests/sec	410	259
Output bandwidth (Mbps)	1407	1454
Memory (MB)	1079	2628
CPU (%)	4.9	12

I measured the number of connections and requests per second by the server-status handler. The handler of the version 2.2.22 does not return the correct value of the usage of bandwidth. I cannot compare the value of the version 2.4.1, so I measured the 5 minutes average of the output bandwidth of the network interface. I measured the usage of memory and CPU by prstat -a showing the total usage of processes of the httpd.

The output bandwidth shows the both versions carried similar loads. It included the rsync and FTP, but HTTP occupied most of it. The version 2.4.1, however, had the much smaller connections and requests per second then the version 2.2.22. I have not read the source code yet, so I cannot state the reason of this situation. I guess these versions use the different ways of measuring those values. As for the usage of memory and CPU, the version 2.4.1 used more than twice as much as the version 2.2.22.

I set the similar configurations to both versions. There is no difference in the configurations to explain such the difference of the usage. I tested MPM modules in the version 2.4.1 at first, but got a similar result. I could not understand such large usage of resources, so I tested the built-in worker and got the above result. I observed the usage by the event MPM for a short while. It used similar amount of resources. I cannot use the series of the version 2.4 on ftp.jaist.ac.jp until it come to use much small resources.