06 October 2011, 10:05

Hello,

I am a system administrator for a fairly large university. We are running mahara for the first time this term. Our original design was to use a clustered installation, but we were unable to get it working, so this term we are running as a single node instance (with separate database).

I would love to talk to someone else who is running a large installation and to be able to get their experiences.

Our setup (desired):

1. We use a pair of BigIP F5 Loadbalancers to offload SSL and act as a front door for the cluster.

 2. We have a production cluster of 6 apache servers (moodle and mahara gets served from the same nodes, running on the different ports).

3. We have a NFS server that provides /moodledata and /maharadata to each application node

4. Postgresql 9.0.4 database server for all.

Some of our problems included:

1. Mahara can only store sessions on the file system. PHP file locking was not compatible with NFS. Our solution was to store sessions outside of the NFS directory and trust the Loadbalancer to always send people to their node (we loose fault tolerance).

2. We use SSO (mahoodle) with moodle. There was a lot problems setting it up. We got something that sort of worked eventually, but not perfectly. For example we were unable to set the main URL, and each node would respond with their hostname instead of the "https://eportfolio...."  In the end we got some errors we were unable to fix so we installed single instance, not behind load balancer setup.

If there is anyone else with simlar setup and is able and willing to share some of their solutions / experiences that would be greatly appreciated.

Thanks,

Greg

06 October 2011, 10:25

Hi Grzegorz,

We've done several installations of this kind of nature, our biggest was a moodle installation for 250,000 users with mahara attached.

We've done some talks on this, the most recent being at MaharaUK11. I've put my slides up at http://www.slideshare.net/andrewnicols/mahara-uk-2011-building-mahara-for-multiple-institutions-8410961

There should be no reason for the sessions to be on the NFS share. We're currently using a customer's SAN for this, and have previously used Solaris 10's ZFS NFS server. Any compliant NFSv3 or v4 server should 'Just Work'. What kind of issues were you seeing there?

With regard to the SSO and nodes changing hostnames, what OS are you running? Would you be able to share the relevant virtualserver configuration?

We were successfully running Apache 2 on Debian Sarge, Etch, and Lenny in this kind of configuration. We currently run this on Debian Squeeze with no issues.

The only difference in our configuration was that our load balancers weren't doing the SSL offloading.

If you need help on this, we might be able to help.

Thanks,

Andrew

06 October 2011, 17:50

We also have a cluster where the sessions are stored in NFS, so I would be curious to hear more about the problems you were seeing there.

As for SSL proxies, we have added a new setting for that and that will be available in Mahara 1.5:

  https://bugs.launchpad.net/mahara/+bug/829674

Cheers,

Francois