Re: Multiple Informix Instances with 9.4 UC4 version

Kalimera Martin, Thanks for your info. Are you aware of any Informix manuals that might explain the prons and cons of multiple informix instances on the same server Regards Alex On 24/04/06, Martin Fuerderer <MARTINFU@de.ibm.com> wrote: > > Kalimera, > > different Informix instances are completely independent > from each other and do not even know of each other. > Therefore they would (potentially) compete for resources. > > You can of course limit the CPU and memory usage of > an IDS instance, e.g. by running it with a number of CPUVPs > that is less than the number of physical CPUs on the > machine. That way you can also "share" the resources > of a machine between several instances. > However, such "load balancing" is rather coarse > grained and therefore probably not desirable. > > I'm not sure how you (will) configure the LPARs on the AIX > level. It might be possible to impose limitations there as > well, though it is equally questionable whether these > limitations would be desirable, as they are probably even > less dynamic then limitations of the IDS instance level. > > I would probably try to ask the question the other way round: > > By separating the databases to run on different instances, > you are then able to perform certain administrative tasks > on one instance (i.e. database) while the other instances > (i.e. other databases) are still fully operational. > If you run all databases in one single instance, then taking > down that instance for administrative tasks will take all > databses off-line. > Administrative tasks that require downtime can be as simple > as doing a version upgrade, or can be as complex as > doing a restore after a disk crash or an accidential drop of > a table or database ... > Based on the importance of above things I would figure out, > how to combine or separate databases on instances. > And with that schema I would then find a way to get the most > out of the resources (performance wise). > > Regards, > Martin > -- > Martin Fuerderer > IBM Informix Development Munich, Germany > Information Management > > informix-list-bounces@iiug.org wrote on 24.04.2006 13:10:54: > > > > I have gone through the posts since 1997/8 and it seems that it was > > strongly advised to avoid running multiple instances on the same box, > > some very educational replies by Art S Kagel. This also seems to be the > > advice of Informix in its performance tuning manual. > > > > We are planning to deploying 3 databases in an AIX box with 32 GB mem > > and 8 CPU. Two of the databases are very processing intensive > > especially at night, where batch jobs are run, the 3rd database is a > > much smaller database. We are in a debate of how these should be > > deployed > > > > The options are : > > > > 1) One LPAR, 3 instances, one for each database a total of 32GB mem and > > 8 CPU. > > > > 2) Two LPAR, 2 instances, one for each of the processing intensive > > database and the less intensive processing database will be imported > > together with one of the large one, 16GB mem and 4 CPU per LPAR > > > > How Informix manages resources between several instances? What are the > > prons and cons of the above configurations? > > > > Thanks > > Alex > > > > _______________________________________________ > > Informix-list mailing list > > Informix-list@iiug.org > > http://www.iiug.org/mailman/listinfo/informix-list > > -- Regards Alexis Kyriakides