Java Dialog Instance

[Former Member]

Hi,

we installed a additional dialog instance for our entprise portal. the instance is up&running, but no one is connected. i can manage the instance in the config tool and added 3 servers.

do i have to set up a additional web dispatcher? - like mentioned in this thread )

[michael_mulvey · Accepted solution]

Hi

Yes. Agree with Michael above. You would need a load balancer so that all your users will not logon to one specific server.

Michael

[Former Member]

hi,

you DON'T need a webdispatcher.

instead of using the 'normal' url (e.g. http://portal:62500/irj/portal) use the port of the message server (e.g. http://portal:8126/irj/portal). the message server does the load balancing.

[Former Member]

ok.

why can't i find a 'official statement' on sap.com? the need of the webdispatcher is not mentioned in the installation guide or somewhere else.

[Former Member]

Well the web dispatcher is mentionend, for example in the master installation guide:

Web Dispatcher
The Web Dispatcher is recommended when you use an SAP system with multiple SAP Web
Application Servers for Web applications. It is located between the Internet and your SAP system.
It is the entry point for HTTP(S) requests into your system, which consists of one or more
Web application servers. As a "software Web switch", the Web Dispatcher can reject or accept
connections. When it accepts a connection, it balances the load to ensure an even distribution
across the servers...

And in my opinion adding a web dispatcher is not much work. You will certainly need a couple of days, when you do it the first time. But once you understood it, it is only a matter of minutes to get a web dispatcher running.

Cheers Michael

[Former Member]

thank you for the information.

we allready have a webdispatcher running. we hoped to avoid install a another, respectively more than one (test, production and so on).

[thunder_feng]

Hi,

When you have your first instance, i.e, the Central Instance, your users should connect to this system via URL like this:

http://<ci_host>:<port>/xxxx

Then the dispatcher in the CI will distribute all the requests to the server node(s) as a kind of load balancing.

While later if you install an additional Dialog Instance, the DI will have its own URL for accessing:

http://<di_host>:<port>/xxxx

and of course the dispatcher of this DI will distritute the requests inside this instance.

So your users can either access the DI or CI directly with the specific URL, or you can configure any load balancer in front

of the two(or more) instances.

SAP WebDispather is just one of the chooses. --- not the only one.

As you mentioned, you have already 1 webdispathcer, but not sure what it is used for.

While if it is just used for this system, so you can add the DI to to the balancing list, that is it.

Not needed to install another web dispatcher.

Regard,

Thunder

[Former Member]

Generally yes, you need the webdispatcher, or a 3rd party http load balancer...

... unless you give the http url of the dialog instance to 50% of the users

Cheers Michael

[Former Member]

Hi ,

Can you make sure port is different for 2 isntances. (can check in /usr/sap/sapservices & do netstat -a in UNIX).

Can get clear information from dev_bootstrap & dev_server0 files.

For load balancing you need to configure WebDispatcher, as mentioend below.

http://help.sap.com/saphelp_nw04/helpdata/en/42/5cfd3b0e59774ee10000000a114084/frameset.htm

Regards

Nagaraju