On Jan 5, 6:02 am, “Ericson S.” [email protected] wrote:
Of course unlimited scaling will destabilize your environment. That’s why
you do some basic investigations and set your min and max values for spawned
lsapi children. Its the same issue if the startup 20 mongrels on a dual core
machine.
No, it’s decidedly not the same. If you startup 20 mongrels on a dual
core machine, then the performance will be the same whether those 20
are in use or not. It’s not an issue of CPU, to a large extent, but of
memory…
The point is if I know that my theorerical maximums are 10 mongrels
(lsapi clients). Then once I set that, I no longer have to worry about it.
But why wouldn’t you want all 10 running if 10 is the maximum?
Litespeed will put them up or tear them down – up to the maximums I set, or
down to the minimums – based on traffic, memory and load.
Why would you pay the penalty of processes startup and teardown?
So destabilizing your environment is not an issue.
Sure it is. What happens if you have high traffic during a cron job?
You’ll have max mongrels running, using all available RAM with enough
left over to allow the machine to run efficiently. The cron job starts
and bam you’re in swap.
Now, I know what you’re going to say: You’ve set the maximum too high.
Yes, I agree with that technically, but in practice, a LOT of people
forget about daily, weekly, and monthly cron jobs, etc.
Also, people tend to log into production machine and run code for
various purposes, sometimes as part of routine. With fluctuating
number of mongrel processes, this can work for a long time, then
suddenly take the machine into swap for no apparent reason.
Technically, you’re 100% right, all of this can be avoided with your
method. Operationally, I’m quite convinced it’s not a good idea.
After all Apache does the same thing governed my max child clients.
Yes, and in my experience large websites don’t use this feature for
the reasons I’ve mentioned above.
And the gravy on the steak? You don’t need monit for all of that.
But you do need monit to monitor lightspeed itself, so you’ve gained
nothing.