Re: replication

From: "Georg Walk" <Georg.Walk@cai.de> > >I am looking for people having experience with installation and managing an >informix-database with replication. I asked informix and distributors in >Germany for installations and i get not enough informations. I asked the >markting-people and the answer is: no problem. And when I say "please tell >me a customer" nothing happend. Heh. Imagine that: marketing says something is no problem. Well, for them, it generally isn't a problem, because they don't have to do it. :-) There are two types of replication, high availability and continuous or enterprise. HA has been around for a bit and seems to work well. CDR is newer and was a bit buggy in early releases. Evidently it works well in 7.31 or better. There are people using it. We aren't -- yet. :-) HTH. ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

Obnoxio The Clown (obnoxio@hotmail.com) wrote: : From: "Georg Walk" <Georg.Walk@cai.de> : > : >I am looking for people having experience with installation and : managing an : >informix-database with replication. I asked informix and distributors : in : >Germany for installations and i get not enough informations. I asked : the : >markting-people and the answer is: no problem. And when I say "please : tell : >me a customer" nothing happend. : Heh. Imagine that: marketing says something is no problem. Well, for : them, it generally isn't a problem, because they don't have to do it. : :-) : There are two types of replication, high availability and continuous : or enterprise. HA has been around for a bit and seems to work well. : CDR is newer and was a bit buggy in early releases. Evidently it works : well in 7.31 or better. There are people using it. We aren't -- yet. : :-) : HTH. Just to add, from experience with a couple customers, I have worked in both high avaiability (actually caled HDR by Informix; High availability Data Rep.) and continuous (now called ER or enterprise replication). I don't think I can give any contacts or names with the customers, so I won't risk it. What I had noticed though is a couple things: With 7.3x ER works well. The bugs seem to have been fixed. This is true as long as you follow the rules. Set things up by the book and make sure to follow procedures and guidelines outlined in the reference or in classes. HDR works even better than ER. This one has been around for quite a bit. Again, you have to set it up by the book (if you don,t it won't come up at all) and try not to do anything to cutesy with it. The differences between the two are extremely important as well. HDR replicates the entire instance and is only one direction. It comes in two flavors, syncronous and asyncronous. Syncronous is similar to a two-phase commit in that you are guaranteed the data is on both servers before control is returned to you. Asyncronous doesn't make that guarantee. ER is defined on a per-table basis (Actually, its scope can vary from that to column or join) and each replicate must be defined. This can quickly balloon into hundreds of replicates which can be grouped together, but still it can be a nightmare. There are advantages to ER. You can define an update-anywhere relationship, you have more control of what is replicated, and you can make long strings of replicates that could encompass many servers. HDR is limited to two different servers. HTH -- Rob Wilson rwilson@ntsource.com