PostgreSQL on FreeBSD
freebsd-questions-local at be-well.ilk.org
Mon Oct 27 13:04:29 PST 2003
I haven't used that software since it was called postgres,
but I'll wade in anyway...
Wayne Pascoe <freebsd-questions at penguinpowered.org> writes:
> Hi all,
> I'm trying to configure and tune postgresql on FreeBSD 4.9. We want to
> allow at least 128 concurrent connections but preferably 256.
> Looking at the documentation, we should be okay if we set the following
> in our kernel to achieve this:
> kern.ipc.somaxconn = 512
> kern.ipc.shmall = 65536
> kern.ipc.shmmni = 128
> kern.ipc.semmni = 8
> kern.ipc.semmns = 256
> Now, I have three questions...
> 1. Why do we have to set these in the kernel ?
> Why does setting them in
> /etc/sysctl.conf or /etc/loader.conf not work ?
You're doing something wrong. That's all I can say when the
description of the failure is just "not work".
> 2. Is there a recommended list of settings that we should use in our
> kernel to allow 128 connections and 256 connections ?
A single recommendation, no. It's been discussed. You started with
tuning(7), I assume.
> and lastly,
> 3. What is the impact on the rest of the system likely to be by setting
> aside this memory as shared memory ? Is it then no longer available to
> other applications like Apache and Exim ? Are there any other
> performance issues that we should be aware of ?
Yes, the memory is pulled out of the general pool, and no, I don't
think there will be any other noticeable effects at those settings.
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