Grouper Users - Open Discussion List

[Chris Hyzer <>]

Let me say another thing... if you get the latest oracle driver jar, and 
configure the rac nodes in the connect string of 
grouper.hibernate.properties, e.g.


hibernate.connection.url = 
jdbc:oracle:thin:@(DESCRIPTION=(FAILOVER=on)(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=server1.school.edu)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=server2.school.edu)(PORT=1521)))(CONNECT_DATA=(SID=myid)))

<note, you will need to adjust the failover settings etc>

Maybe you need to adjust the c3p0 settings so the connections timeout after 
some short period of time (1 minute?)

Then I would think when a rac node went down, then the driver would use the 
other node.  However, on our non-grouper systems, we tried this (maybe it was 
our c3p0 settings...), but it didn't really work when a rac node failed.  The 
disadvantage of this is there is not the ONS to proactively tell the driver 
to take a node out of the pool, however, the hardcoded lists is better then 
nothing if ONS is not available in Grouper yet.  Bottom line, it might be 
worth a shot to try something like this and see if it works until ONS :)

Thanks,
Chris

-----Original Message-----
From: Chris Hyzer 
Sent: Thursday, June 09, 2011 9:24 AM
To: 'William G. Thompson, Jr.'; Peter DiCamillo
Cc: 

Subject: RE: [grouper-users] Grouper and database failover

> Curious if you (or anyone else) has also consider a NoSQL option for
> this?  OrientDB looks particularly interesting...
> http://code.google.com/p/orient/

The Grouper API heavily depends on a relational database...

> We're looking at the possibility of configuring Grouper so we can use
> database failover. We'd like to be able to keep Grouper up during database
> maintenance, and also in disaster recover situations. We use Grouper with an
> Oracle database and with tomcat. We also have some java programs which use
> the Grouper API and do not run under tomcat.
> 
> I don't have extensive knowledge of Oracle or jdbc, but some quick Google
> research suggests that this may be possible, and the recommended method
> involves using Oracle's Fast Connection Failover mechanism.
>
> Does anyone have experience with Grouper and database failover? Are there
> known reasons why it could or could not be made to work?

Here is my understanding... FCF requires either oracle's db pool where you 
configure the ONS and that tells it what servers are in the pool, and which 
ones to take out when they go down.  You can use FCF with c3p0 (our db pool) 
if you use the "simple fan" where you write code to listen for ons events and 
adjust the pool accordingly (sounds less appealing to me).  Right now Grouper 
uses c3p0 and a DB driver, so if that is all that is needed, configure it as 
you like.  If you are using ONS, I think we will need to make the pool type 
configurable, and do some work to make sure it is ONS compatible.  Penn is 
probably going to need this at some point, and we use ONS for other things, 
so we will add this into Grouper at some point if someone else doesn't do it 
sooner :)

Btw, we are just using hibernate with c3p0 in hibernate, maybe there is a way 
to adjust the grouper.hibernate.properties to use fcf without changing code 
(I wouldn't bet on it, but maybe) :)

Thanks,
Chris