Forum .LRN Q&A: Univ. of Valencia is running OACS 5.1 with Postgres 8.1.3 in our production server


We are pleased to communicate that University of Valencia is running OACS 5.1 with Postgres 8.1.3 from one week in our production server. All is ok and the performance is better.

The general recipe was:

-Stop aolserver
-Dump from Postgres 7.4.9 with pg_dump on text file.
-Stop postgres7.
-Start postgres8 (createdb, createuser, createlang)
-Configure postgres8 with all compatibility ON in postgresql.conf:
add_missing_from = on
regex_flavor = extended
default_with_oids = on
-Restore with psql the DB in postgres8.
-Generate the next function:
create or replace function bitfromint4 (integer)
returns bit varying as '
return $1::bit(32);
end;' language 'plpgsql' immutable strict;
-Vacuum full verbose analyze;
-Start aolserver

We have too patched the plsql function content_item__del.
Some referencial integrity problems not shown in P7 raising in P8. This is in:

Best regards,


First, congrats on your deployment. It seems like a lot of work!

Second, we are planning on rolling this out on one of the bigest universities in Mexico (130,000 users), and im in charge of dimensioning (what hardware do we need to buy).

I was wondering if you could share anything about your own deployment regarding this.

Hello, Alex!

Our numbers (average):

Users: 60000 students, 3500 teachers
Classes: 8000
Simultaneous connections: 200

Aolserver: Debian AMD-64 Opteron (2 CPU) 1.6 MHz
Aolserver 4.0.10
Postgres: Debian AMD-64 Opteron (4 CPU) 2.0 MHz
Postgres 8.1.3


Here is some information that we collected. we have up to 1200 concurrent users, up to 750 concurrent transfers (i.e. parallel pound sessions)

The hardware you need depends to a big deal on the applications and usage patterns.

best regards

Jose, thanks for the quick response!

Ok, so we are finishing this up, and im thinking we do not have the bandwidth demand that you can probably see in Gustaf's or your own setup.

Id assume gustaf has a pc per student, and they all are on a high speed connection (i mean, 20,000 online exersises per hour...theyve all gotta be clicking like rabbits).

In Valencia probably they also have this kind of setup (lots of in-campus connectivity)

Our setup will be quite different, we probably will have most users connecting from outside the university, and we have a limited bandwith at that (about 50MBit).

So this brings me to ask, whats the bandwith demmand you have in your setup?

I mean, at the peak hour are you filling up a couple of GigaBits?, a couple of megabits?, less than a megabit?

This can help me estimate that we need more bandwith (for example), or more horsepower, depending on our own budget limitations.

We at Mannheim updated our Linux to SuSE 10.0 with PostgreSQL 8.0.8 and just did the upgrade with OpenACS 5.1.

So far the upgrade seems fine. Many thanks for the information.

can we say this are the officials instructions for 8.1.x?
(I've added link to this wiki page in the install docs)
Thanks for posting this to the wiki. I was able to install simply by turning the compatibility flags on. It seems that bitfromint4 is already created in acs-kernel/sql/postgresql/postgresql.sql
I managed to get 8.2beta3 to run after trying in vain to get 8.1.5 to work.

What I realized is the following (which was probably the reason why 8.1.5 did not work out either).

DON'T have xotcl-request-monitor installed. I have no insight into what it is exactly doing which could cause this but in 10 out of 10 times (different sites) that I tried moving to 8.1/8.2 ONLY the installation which had not xotcl-request-monitor (XRM) installed worked.

Initially I suspected XRM to write into the database and that the insert was broken, but ney, that was not the reason as the site just works happily.

I could reproduce this behaviour on 5 different systems running xotcl and XRM from HEAD with AOLserver 4.5 and the latest sources.

After I reinstalled the database, recompiled the nspostgres driver to match the database version and some more performance tuning I made a fresh checkout of xotcl and the request-monitor and now it works on two of the five sites.

In case you wonder about our settings for the tuning:

very helpful information! Thank you for sharing, Malt!