RE: Cluster with informix.

I agree -- I don't think a cluster is really worth it. We have a very critical app. running on a small HP K460 box (2 Gb memory, 70 Gb disk, 4 CPU), connected via HDR to a similarly-configured K400 box. The two boxes are several hundred miles apart, and yet replication to the secondary is within a second or two. There are *several hundred* connections (sessions) all the time, and those are not "real" users, but transaction servers, which bang on the engine a lot more than that many actual users would. HDR has worked GREAT for us, and I HIGHLY recommend it when your goal is high availability (probably why it's called "High-availability Data Replication"). No, it's not as flexible as Enterprise Replication, but it has much less overhead than ER, and it's much easier to administer. If you've only go 100 users, I'd recommend that you get a couple of good, solid boxes, set up HDR between them, make sure your 4GL code is kept up to date on both of the boxes, and then figure out some way to smoothly and quickly switch users over to the secondary if the primary should ever go down. HTH, Paul Mosser -----Original Message----- From: Obnoxio The Clown [mailto:obnoxio@hotmail.com] Sent: Saturday, April 29, 2000 4:45 AM To: cmp@pty.com; obnoxio@hotmail.com Cc: informix-list@iiug.org Subject: Re: Cluster with informix. From: "Centro Medico Paitilla" <cmp@pty.com> > >On 27 Apr 00, at 8:00, Obnoxio The Clown wrote: > > > From: "Centro Medico Paitilla" <cmp@pty.com> > > > > > >We are evaluating an HA (Cluster) solution from SUN > > >Microsystems and IBM, but i have some questions about the > > >capacity of Informix server of work in that environment. I hope that > > >someone can help me with this. > >What's exactly the problem with Sun Cluster and Informix? Is it is >important to me because my applications are in Informix 4GL RDS. >What do you think about IBM HACMP and informix? Why do you want a cluster? What's wrong with just having a nice big box? > > Informix doesn't really support Sun Clusters, or is it that Sun Clusters > > don't support Informix? Depends on who you talk to. But I've just been >to > > a similar debate recently, and the upshot in our case was that we are > > going to Enterprise Replication because we need to propogate our >database > > from a primary server to a backup server and to a reporting box and to a > > development box and.... > > > > The key with ER is to get your database designed correctly from the >get-go > > for ER. If you're in that happy position, I think ER is a great way to > > solve this. Another possible solution, which we currently use, is to use > > HDR for fault tolerance (and it is very tolerant of our faults! :) and >do > > some of the reading of data from the secondary. So we get load balancing > > on that basis. But that might be difficult if you're not using ODBC. > > > >This is a limitation for me, because my critical applications are not >using ODBC. Querix or D4GL may be a solution for this... Forget it. :-) > > >1. Do I have to buy Informix Paralell Server or IDS.2000? It is an > > >OLTP environment... > > > > There is no such thing as Informix Parallel Server, that sounds like an > > Oracle-ism. You might be thinking of Informix XPS or EDS, and that isn't > > for OLTP, it's for decision support. So you need IDS.2000. > > > > >2. With the case that we have two machines in cluster using a > > >cluster software from a machine provider, Can Informix servers work > > >together sharing 50% of the work? > > > > Yes and no. You can't run in a Sun cluster, but you can use Enterprise > > Replication to allow both machines to do half the work each. > > > > >3. If I have an application running on 4GL (RDS), Do I have to buy > > >licences of informix products for both machines? > > > > Yes. > > > >I don't understand that, because if I implement an cluster solution >based in cluster software (SUN or IBM) the informix-4GL will be >installed only in the primary server....and the cluster software do >the rest...??? If you're licensed per user, then does it matter which box it's on? :) > > >4. Is Informix data replication capability more efficient that HA > > >environment based on cluster software from a machine provider? > > > > I guess so, because it's supported. :-) > > > > Another possible solution, which may be better overall, is to have a > > three-box solution. If you were looking at two (say) E4500's, you might > > replace that with 3 E450's, where one would be just for 4GL >applications, > > one would be a primary server and one a secondary, read-only server. You > > could do all your data entry onto the primary, run your reports against > > the secondary and have all the 4GL load on the third box. YAMMV. > > > >This is interesting suggestion, but it has a weak point .... the third >box. If the third box fail, the system would not be available. OK, so get 4 boxes. Two "client" boxes, two server boxes. Or use the server boxes as failover application servers. > > How much load are you expecting to put on the server? Clustering always > > seems a bit of an extreme solution... > > >That's true, but in this case we have a critical healthcare >application that most be available all the time (7X24). We have 100 >concurrent users. I don't think a cluster is worth the hassle. There are other, less painful ways of ensuring resilience. ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com