Linux max server processes

Question

I have a GNU/Linux Debian server running: apache, jboss, proftpd and postgresql (RAM: 16GB, 4 core Xeon). Max Apache process is 1200, same thing for the Jboss DB Pool. And I can have up to 400 simultaneous FTP download. Load average can raise 5 (1 most of time). What do you think about that? Is this server considered as "too loaded"?

Regards,

Answer 1

The number of processes you should be running should not exceed what you have ram for; 1200 Apache worker processes sounds like too many, you may not have enough ram for that many (especially with all those other things).

It's essentially all about tuning memory usage (and IO usage), rather than number of tasks.

Don't worry about a high load average - load average includes processes waiting for IO, and there could legitimately be a lot of them on a well-utilised box. We have many servers which run all day at 20+ ; we need to run them this hard to get the most out of them hardware.

Answer 2

A system is too loaded when it becomes unresponsive.

System load average can be deceiving because you can have a system with a high load that is still quite responsive to requests...

If your system is slamming virtual memory (thrashing the hard disk), is low on actual memory, or times out...pauses when you're trying to enter information at the keyboard, network connection time out, etc...then you need to look at finding what is bottlenecking and work on fixing that. If the response time is acceptable and the system behavior is acceptable without errors then you should be just fine.

I'd keep an eye on your memory use and disk use and possibly network throughput and otherwise listen to your users for feedback.

Answer 3

You can expect a busy server to have a load equal to the number of cores in your processor plus the number of IO devices you have. A loadavg of one with a 4 core box is not particularly high.