Machine available for community use

"Gavin M. Roy" <gavinmroy@gmail.com> writes:

I'm currently in the process of having Gentoo linux reinstalled on the
box since that is what I am most comfortable administering from a
security perspective. If this will be a blocker for developers who
would actually work on it, please let me know.

Personally I'd prefer almost any of the other Linux distros.
Gentoo always leaves me wondering exactly what I'm running today,
and I think reproducibility is an important attribute for a benchmarking
machine.

regards, tom lane

If you're interested in using the box, name what you want installed.

On 7/25/07, Tom Lane <tgl@sss.pgh.pa.us> wrote:

"Gavin M. Roy" <gavinmroy@gmail.com> writes:

I'm currently in the process of having Gentoo linux reinstalled on the
box since that is what I am most comfortable administering from a
security perspective. If this will be a blocker for developers who
would actually work on it, please let me know.

Personally I'd prefer almost any of the other Linux distros.
Gentoo always leaves me wondering exactly what I'm running today,
and I think reproducibility is an important attribute for a benchmarking
machine.

Tom, have any specific ideas in mind for using the system? While I'm
used to having more disks it could be useful nonetheless for the tests
I used to run if there are no other ideas.

Rats, I've always liked Gentoo. ;)

Regards,
Mark

Note it's a 28 disk system, and I can allocate more if needed, but I
was going to use one MSA for internal use.

"Gavin M. Roy" <gavinmroy@gmail.com> writes:

If you're interested in using the box, name what you want installed.

Personally I use Fedora, but that's because of where I work ;-).
I have no objection to some other distro so long as it's one where
other people can duplicate your environment easily (no locally
compiled stuff). A disadvantage of Fedora is its relatively short
support lifetime --- if you don't want to have to reinstall at least
once a year, something else would be better.

regards, tom lane

Ubuntu server? Slackware? Not a fan of Centos, RHEL or Fedora...
What about on the BSD side of things?

On Wed, 25 Jul 2007, Gavin M. Roy wrote:

Ubuntu server? Slackware? Not a fan of Centos, RHEL or Fedora...

Unless you did a custom intall, using Ubuntu server would expose the
people using your server to the quirks of how the Debian packages for
PostgreSQL differ from other Linux distributions. I'm not sure whether
that would be a good (shine some light on that underdocumented area) or
bad (get in people's way) thing. The way they make it easier to manage
multiple clusters might actually be ideal for what you're trying to do,
let people have their own cluster and stay out of each other's data space
at least.

I think Slackware has all the non-mainstream issues of Gentoo, but without
the advantages Portage brings.

What about on the BSD side of things?

Since your goal is improve scalability on Linux, I think you'd be best
focusing on that. There's just enough low-level differences between the
two that I'd hate to see you put resources into improving scaling, only to
discover it doesn't actually help what you put into production because the
platform is too different.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD

On Wed, 2007-07-25 at 08:50 -0700, Mark Wong wrote:

On 7/25/07, Tom Lane <tgl@sss.pgh.pa.us> wrote:

"Gavin M. Roy" <gavinmroy@gmail.com> writes:

I'm currently in the process of having Gentoo linux reinstalled on the
box since that is what I am most comfortable administering from a
security perspective. If this will be a blocker for developers who
would actually work on it, please let me know.

Gavin, I'd like access please. This sounds very cool. We'll be able to
show each other directly what's going on, even log on together to
inspect various aspects of runs.

Will you run a booking system?

Could you give us some details about myYearbook.com's application? I
feel we should prioritise work slightly so that the contributor can see
some benefit coming their way in the longer term.

Personally I'd prefer almost any of the other Linux distros.
Gentoo always leaves me wondering exactly what I'm running today,
and I think reproducibility is an important attribute for a benchmarking
machine.

Tom, have any specific ideas in mind for using the system? While I'm
used to having more disks it could be useful nonetheless for the tests
I used to run if there are no other ideas.

Mark, If you're thinking TPC-E, so am I. Where are we with the TPC-E
toolkit you guys were working on?

Initially though, I'd like to do some tests on CVS HEAD with large
shared_buffers settings, so the 32GB RAM will come in handy for that and
no worries about disks.

Rats, I've always liked Gentoo. ;)

I'd agree with Tom on that: we need a system that remains the same over
longer periods, not simply a very fast one. I'm OK with Fedora.

--
Simon Riggs
EnterpriseDB http://www.enterprisedb.com

On 7/25/07, Simon Riggs <simon@2ndquadrant.com> wrote:

On Wed, 2007-07-25 at 08:50 -0700, Mark Wong wrote:

On 7/25/07, Tom Lane <tgl@sss.pgh.pa.us> wrote:

"Gavin M. Roy" <gavinmroy@gmail.com> writes:

I'm currently in the process of having Gentoo linux reinstalled on the
box since that is what I am most comfortable administering from a
security perspective. If this will be a blocker for developers who
would actually work on it, please let me know.

Gavin, I'd like access please. This sounds very cool. We'll be able to
show each other directly what's going on, even log on together to
inspect various aspects of runs.

Will you run a booking system?

Could you give us some details about myYearbook.com's application? I
feel we should prioritise work slightly so that the contributor can see
some benefit coming their way in the longer term.

Personally I'd prefer almost any of the other Linux distros.
Gentoo always leaves me wondering exactly what I'm running today,
and I think reproducibility is an important attribute for a benchmarking
machine.

Tom, have any specific ideas in mind for using the system? While I'm
used to having more disks it could be useful nonetheless for the tests
I used to run if there are no other ideas.

Mark, If you're thinking TPC-E, so am I. Where are we with the TPC-E
toolkit you guys were working on?

Initially though, I'd like to do some tests on CVS HEAD with large
shared_buffers settings, so the 32GB RAM will come in handy for that and
no worries about disks.

Yeah, the the C stored functions are half done but there is a finished
implementation for the pl/pgsql stored functions. It's in decent
shape otherwise, although it's mostly based on the 0.32 version.

Rats, I've always liked Gentoo. ;)

I'd agree with Tom on that: we need a system that remains the same over
longer periods, not simply a very fast one. I'm OK with Fedora.

True, I'll settle for whatever everyone agrees with.

Regards,
Mark

On Wed, 25 Jul 2007, Tom Lane wrote:

Gentoo always leaves me wondering exactly what I'm running today,
and I think reproducibility is an important attribute for a benchmarking
machine.

At this point, there's enough performance variations even between
individual Linux kernel releases that I'm not sure how much
reproducibility you're ever going to get here. Are the differences
between Gentoo and RHEL any bigger than those, say, between RHEL and SuSE?

The idea of setting this up with a long-term stable distribution runs
counter to one of the things that I think is important to explore here,
which is testing how more recent Linux kernels have improved their
scalability. Do you really want to put a lot of time into identifying and
working around the source of a problem with the typically older kernels
that ship with the more stable releases if one answer is "that goes away
if you use 2.6.21 or later because they fixed the bug that caused it"?
I've watched that sort of thing happen with PG+Linux, and when involved in
one of the recent roving talks Gavin mentioned I recall him mentioning a
bit of that experience himself. You'd be hard pressed to find a better
platform for that kind of experimentation than Gentoo.

The best you can hope for, I think, is that you can walk away with some
general benchmark expectations and "on Gavin's machine, this worked
better"; then try to replicate that improvement elsewhere. If you want to
push bleeding edge performance, I'd expect it's impractical to do that and
target long-term results stability at the same time.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD

Simon Riggs wrote:

On Wed, 2007-07-25 at 08:50 -0700, Mark Wong wrote:

On 7/25/07, Tom Lane <tgl@sss.pgh.pa.us> wrote:

"Gavin M. Roy" <gavinmroy@gmail.com> writes:

I'm currently in the process of having Gentoo linux reinstalled on the
box since that is what I am most comfortable administering from a
security perspective. If this will be a blocker for developers who
would actually work on it, please let me know.

Gavin, I'd like access please. This sounds very cool. We'll be able to
show each other directly what's going on, even log on together to
inspect various aspects of runs.

Will you run a booking system?

Could you give us some details about myYearbook.com's application? I
feel we should prioritise work slightly so that the contributor can see
some benefit coming their way in the longer term.

Personally I'd prefer almost any of the other Linux distros.
Gentoo always leaves me wondering exactly what I'm running today,
and I think reproducibility is an important attribute for a benchmarking
machine.

Tom, have any specific ideas in mind for using the system? While I'm
used to having more disks it could be useful nonetheless for the tests
I used to run if there are no other ideas.

Mark, If you're thinking TPC-E, so am I. Where are we with the TPC-E
toolkit you guys were working on?

Initially though, I'd like to do some tests on CVS HEAD with large
shared_buffers settings, so the 32GB RAM will come in handy for that and
no worries about disks.

Rats, I've always liked Gentoo. ;)

I'd agree with Tom on that: we need a system that remains the same over
longer periods, not simply a very fast one. I'm OK with Fedora.

fedora is probably not a prime example for "stays same over long period"
(which I think is important) since it has pretty short release cycles.
Maybe something like ubuntu LTS, Debian Etch or even CentOS would be
more appropriate (we have debian on a number of very similiar HP boxes
and HP is doing Debian Support now too).

Stefan

Greg Smith wrote:

On Wed, 25 Jul 2007, Gavin M. Roy wrote:

Ubuntu server? Slackware? Not a fan of Centos, RHEL or Fedora...

Unless you did a custom intall, using Ubuntu server would expose the
people using your server to the quirks of how the Debian packages for
PostgreSQL differ from other Linux distributions. I'm not sure whether
that would be a good (shine some light on that underdocumented area) or
bad (get in people's way) thing. The way they make it easier to manage
multiple clusters might actually be ideal for what you're trying to do,
let people have their own cluster and stay out of each other's data
space at least.

for a server like this I don't think anybody cares at all for the
prepackaged postgresql. People are likely to use such a box for
development/testing of new patches and development stuff. so what they
need is a proper toolchain and solid packages. Debian derived
distributions are quite good at that usually (debian etch ships with gcc
3.3,gcc 3.4 and gcc 4.1 for example) and I expect people to simply get
their accounts and do all their work in their home-directories
anyway(which sounds like the normal way to develop on unix like OSes to me).

Stefan

Greg Smith <gsmith@gregsmith.com> writes:

Unless you did a custom intall, using Ubuntu server would expose the
people using your server to the quirks of how the Debian packages for
PostgreSQL differ from other Linux distributions.

I doubt we'd be doing much work with the distro-installed version of
Postgres anyway, so this doesn't seem like a big concern. In fact,
to avoid confusion it might be best if the machine has no
distro-installed Postgres at all. That would help avoid "oops, that
test was run against the wrong server" syndrome.

I do essentially all my development work with installations that are
--prefix'd to user directories and started/stopped by hand; it's just
a lot easier to manage a pile of different versions that way. Plus
I never need to become root. Not sure how other developers work,
though.

regards, tom lane

Greg Smith <gsmith@gregsmith.com> writes:

On Wed, 25 Jul 2007, Tom Lane wrote:

Gentoo always leaves me wondering exactly what I'm running today,
and I think reproducibility is an important attribute for a benchmarking
machine.

At this point, there's enough performance variations even between
individual Linux kernel releases that I'm not sure how much
reproducibility you're ever going to get here. Are the differences
between Gentoo and RHEL any bigger than those, say, between RHEL and SuSE?

The problem I've got with Gentoo is that it encourages homegrown builds
with randomly-chosen options and compiler switches. That may help
squeeze out a bit more speed but it does nothing for stability, nor
reproduceability of results on other platforms which is what we really
care about here.

Another fairly big issue is that we need to know whether measurements we
take in August are comparable to measurements we take in October, so a
fairly stable platform is important. As you say, a fast-changing kernel
would make it difficult to have any confidence about comparability over
time. That would tend to make me vote for RHEL/Centos, where long-term
stability is an explicit development goal. Debian stable might do too,
though I'm not as clear about their update criteria as I am about Red Hat's.

The idea of setting this up with a long-term stable distribution runs
counter to one of the things that I think is important to explore here,
which is testing how more recent Linux kernels have improved their
scalability.

Dunno if Gavin wants to manage multiple systems, but for most of what
I'd like to do a bleeding-edge kernel is exactly what I do not want.

regards, tom lane

Tom Lane wrote:

Greg Smith <gsmith@gregsmith.com> writes:

On Wed, 25 Jul 2007, Tom Lane wrote:

Gentoo always leaves me wondering exactly what I'm running today,
and I think reproducibility is an important attribute for a benchmarking
machine.

At this point, there's enough performance variations even between
individual Linux kernel releases that I'm not sure how much
reproducibility you're ever going to get here. Are the differences
between Gentoo and RHEL any bigger than those, say, between RHEL and SuSE?

The problem I've got with Gentoo is that it encourages homegrown builds
with randomly-chosen options and compiler switches. That may help
squeeze out a bit more speed but it does nothing for stability, nor
reproduceability of results on other platforms which is what we really
care about here.

Another fairly big issue is that we need to know whether measurements we
take in August are comparable to measurements we take in October, so a
fairly stable platform is important. As you say, a fast-changing kernel
would make it difficult to have any confidence about comparability over
time. That would tend to make me vote for RHEL/Centos, where long-term
stability is an explicit development goal. Debian stable might do too,
though I'm not as clear about their update criteria as I am about Red Hat's.

Fully agreed (on the RH/CentOS and longterm stability stuff) debian is
even more stricter/conservatve than RH usually - they only have security
bugs and on very rare occation bugfixes for major issues(RH sometimes
adds new features and stuff in their point-releases).
Debian etch seems to be (very) slightly relaxing that - and in fact a
number of people were very surprised to see PostgreSQL updated from
8.1.8 (as shipped in etch) to 8.1.9 with the latest security release :-)
I would agree however that gentoo and also slackware are not "that"
attractive for this kind of work.

Stefan

------- Original Message -------
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Greg Smith <gsmith@gregsmith.com>
Sent: 25/07/07, 18:54:50
Subject: Re: [HACKERS] Machine available for community use

Another fairly big issue is that we need to know whether measurements we
take in August are comparable to measurements we take in October, so a
fairly stable platform is important. As you say, a fast-changing kernel
would make it difficult to have any confidence about comparability over
time. That would tend to make me vote for RHEL/Centos, where long-term
stability is an explicit development goal. Debian stable might do too,
though I'm not as clear about their update criteria as I am about Red Hat's.

Perhaps RH could donate us a RHEL/RHN licence for this?

/D

One thing to take into account is I dont have physical access to the
box (It is in TX, I am in PA). All installs but Gentoo will be
performed by a well trained NOC monkey. *cough*

"Dave Page" <dpage@postgresql.org> writes:

Perhaps RH could donate us a RHEL/RHN licence for this?

I could ask, if there's consensus we want it. It sounded like more
people like Debian, though.

regards, tom lane

Gavin M. Roy wrote:

One thing to take into account is I dont have physical access to the
box (It is in TX, I am in PA). All installs but Gentoo will be
performed by a well trained NOC monkey. *cough*

iLO ?

Stefan