Grouper Users - Open Discussion List

[Chris Hyzer <>]

Im interested to hear what other people are doing, so others please respond 
if you have a good setup.

Here is what we do at Penn:

1. Linux lvs as a load balancer (two servers with heartbeat)
2. This load balances 4 servers behind (this isn't dedicated for grouper, but 
each webapp gets its own tomcat process, e.g. grouper ui and grouper ws are 
in different tomcats... this is important)
  - note, the loadbalancing is very simple, sticky based on source ip 
address, which can fail for some isp's that rotate user's ip addresses, or 
users with roaming laptops, but generally it is ok for academia where we all 
have our own ip address :)  We cant easily change this since the apache on 
the app server does SSL, but this is a weakness.
3. oracle active-standby synchronization, and the jdbc urls will 
auto-failover.  E.g. here is a url:
jdbc:oracle:thin:@(DESCRIPTION=(FAILOVER=on)(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=server1.whatever)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=server2.whatever)(PORT=1522)))(CONNECT_DATA=(SERVICE_NAME=somename.whatever)))

Im not an expert about how this works, but my understanding is that if the 
active fails, there is a manual intervention, and some period of time 
(measured in minutes) to bring the standby up.  Then the apps should work 
again.

Btw, WS doesn't require sticky sessions at the moment... though if you are 
doing some sort of authentication caching, it would be helpful, and in 
general the queries from one service might benefit from going to the same 
server since it might be caching as well.

Note: we don't cluster among tomcats.  If one failed, users would have to 
logout and log back in.  Also, with LVS we had issues where the LVS thought 
an app server was down when it wasn't, or it thought all were down and shut 
down the app.  So we manually remove an app server from the cluster if it 
fails.  We monitor applications with nagios from the outside.

In general we are happy with this setup.  Right now are using WS but not for 
mission critical stuff.  I think we will end up doing this, so I would like 
to find a better architecture for very high performance high availability web 
services (as we have been discussing in earlier threads, but I wont mention 
now :) ).

Thanks!
Chris

> -----Original Message-----
> From: Niels van Dijk 
> [mailto:]
> Sent: Thursday, June 18, 2009 10:37 AM
> To: 
> 
> Cc: Marieke de Wit; Hans Zandbelt
> Subject: [grouper-users] Grouper HA scenarios
> 
> Hi All,
> 
> We are currently exploring scenarios for setting up Grouper in a high
> available, failover setup.
> 
> For the MySQL database, we plan on implementing a standard master-slave
> configuration using two mysql servers.
> 
> For Groupers gui and webservices, the only requirement seems to be that
> sticky sessions need to be handled. Therefore several options seem to
> exist:
> 1) Clustering setup in Tomcat, as described here:
> http://tomcat.apache.org/tomcat-6.0-doc/cluster-howto.html
> 2) Use apache mod proxy in front of tomcat to handle the clustering,
> with sticky sessions enabled, like eg described here
> http://www.markround.com/archives/33-Apache-mod_proxy-balancing-with-
> PHP-sticky-sessions.html
> (of course using java sessionid, not php sessionid)
> 3) use a loadbalancer to handle the sticky sessions and just use two
> separate tomcat instances. Pound (http://www.apsis.ch/pound/) or a
> hardware LB could handle this.
> 
> Did anyone set up grouper in such a way? What solution did you choose?
> And what are your experiences with that solution?
> 
> thanks in advance,
> 
> regards,
> Niels
> 
> 
> 
> --
> Niels van Dijk
> Advanced Services
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