what is Server 0, Server 1, Server 2, Server 3?

[#1]

Hi folks,

I have the portal landscape so DEV & Q has Server 0 when you launch JCMON/configtool/visualAdmin. However, in PRD there are SERVER 0, 1, 2, and 3 when you launch JCMON/configtool/visualAdmin.

What is it for? Is it for clustering or load balancing? Why do we do that and how do we do that?

I would really appreciate your help..

Thanks,

[ravi_joseph · Accepted solution]

server0 will be your central instance (Application server + database) and server1 and server2 are dialog instances ,

this will be used for load balancing, check below link for more help

http://help.sap.com/saphelp_nw04s/helpdata/en/1c/ba295ee20fcd41b6804f1bc602de68/frameset.htm

jo

[Former Member · Accepted solution]

Hi Jo

Not quite correct. Server0 is the first server process for an instance number, server1 is the second etc. They are attached to a dispatcher process. There is one dispatcher per instance number. Users connect to a dispatcher process, generally through port 5xx00, where xx is the instance number.

A central instance is a database plus a dispatcher and at least 1 server. It also has an SDM process. A dialoge instance uses the same data base as the central instance, and also has a dispatcher and at least 1 server process. The server process number for each instance starts at 0.

So, a central instance xx plus a dialogue instance yy, each with two server processes will have

two dispatchers (ports: 5xx00 and 5yy00), two server0 and two server1 processes. (Plus SDM...)

[Former Member · Accepted solution]

HI Michael,

It was a greate reply and make sense. I want to know why do we do that meaning why server 1,2...etc other than Server0. And how do you do that? what's the functionality?

Really appreciate your help..

Thanks,

[Former Member · Accepted solution]

Each server process has a certain amount of memory and threads. When they reach their limits, there are not enough resources to process requests, so the system response time increases. Adding another server process allows for extra throughput.

Dispatchers don't normally get too busy. They're pretty stupid creatures and don't do much work except dispatch requests! Multiple dispatchers are useful for high availablity and fault tolerence.

[Former Member · Accepted solution]

Michael

Can you help me out how to proceed if i need to do it. Our PRD has 4 servers but not Q & D. This is one the task I may need to do it to make landscape look alike...

I would really appreciate your help...

Thanks,

[Former Member · Accepted solution]

Basically you use the config tool and add a server node. Please check out the [SAP Help Pages|http://help.sap.com/saphelp_nw70/helpdata/en/e1/8e51341a06084de10000009b38f83b/frameset.htm] and look for config tool and adding server. There is normally no need to do this on a dev system, although some people do it on a QA system so that it reflects reality (Prod). Each server process needs memory and CPU, so make sure you have enough of those!