1 Websphere App Server for many Lawson env's - how to do

You can use the same Websphere software install & deployment manager for the second environment, but as you suspect you will have to have a separate app server for the second environment. And it is possibleto share the TDS & HTTP Server with the second environment. (Although the documentation doesn't really seem to explain much about how to set up a shared TDS).

However, I prefer to have separate installs of all of these components for each environment. First of all, it completely isolates each, so that any kind of failure in one environment has no effect on the others. Secondly and more important, it means I can have different configuration or patches on the different environments. If we want to install new patches on HTTP server for example, I can install it for one environment, test, and then install it for the next environment.

The one component I might be tempted to share would be the deployment manager - at times it would be conveneint to have a single deployment manager for multiple environments on the same host. But you can't us the same deployment manager for app servers on two different hosts. This is not a restriction of WAS, but is a restriction in the licensing terms if you license WAS-ND through Lawson.

Perhaps you already have two installs for these components are creating a third environment. In that case it is not as critical but I would still perfer separate installs. If you have no need for this flexibility, perhaps you don't even need the second environment at all, just a second productline?

BTW, the install instructions always seem to suggest creating a virtual host in WAS for each environment, but I have found using the predefined default_host to work fine.

it's hard to believe that if we have 2 Env's on a same server ( for what reason it is ) we have to double every things : 2 WAS, 2 Webservers . It's even not possible to reuse the existing Webserver , by using another IP Port.

We have tried to create a second application server in the existing WAS, called server2 with all usual Lawson env parameters for JVM ( LAWDIR, GENDIR, LADBDIR, etc..).
But when we launch the Core Installation ( java -jar LSFCT.jar ) , when arrived to the Webserver part, The installer 'see' that there is an existing Webserver and did not let us to chose another IP Port then the existing one. We hoped here to see somehow Lawson create a new entry in httpd.conf file on the webserver , for a chosen IP Port, but no it didn't .

So our conclusion, so far is : 1 WAS for 1 Env, n WAS for n Env ,even the Env's are on the same server.

Our current Env's are still in 8.0.3, where we managed to have 1 Webserver ( Apache ) manage all Env's, just using different IP Port. In addition, we are using 1 SUN LDAP 5.2 to manage ALL user access to ALL Env's , LID as well as Portal ( Unix authentication by LDAP ).

Moving to LSF9, we see that somehow we are going backward for the technology.
We have not yet explored the IBM LDAP configuration in LSF9, but can imagine that each Env's will require a specific DN. It will be a big job to synchronize all these DN.

You have a problem with sharing the webserver, but you seem to be making a conclusion about the application server side too. Although they share the same branding, the two are very different and loosely coupled.

I think you can share a single webserver if you want - but you will need to customize httpd.conf. What the product can do is one thing, what the installer will automatically configure for you is something else. Even without that configuration I have always hand-edited the httpd.conf file. Of course that will take more work to figure out how to get the right configuration. You will also need to make corresponding changes to default_host or the virtual host settings in the deployment manager. The installer will set up a typical configuration but for your desired configuration you should probably ignore the default_host and set up a new virtual host in Websphere for each enviornment. The installer will not set up this kindo of config -- nor do I think the Lawson docs will explain much about that kind of configuration. The Lawson documents tend to describe a simple, default installation, not all the various configurations that are possible and might be prefered by some sites.

And as far as the application server is concerned, there is certainly no need to install two full copies of the software libraries, nor even two deployment servers unless you want to do so - as long as you create a "server2" app server instance as you have apparently done.

Now the LDAP issue is a bit trickier. I suspect it might be possible to share a single TDS & single DN for two environments, but I doubt Lawson would support it. Assuming you have separate DNs, are you wanting to synchronize the passwords accross environments, or the complete user profile? If you want to synchronize the passwords then the LDAP bind process should achieve that goal.