Listner on Dialog instance

[Former Member]

Dears,

I want to know,Is listner exist on dialog instance also or it exist only on central instance.

If it does not exist in dialog instance then how this instance communicate to database means in this it would be communicating to central instance and that will be updating data in database.So please clear its communication process.

Shivam

[Former Member · Accepted solution]

Hi,

Listener does not exist on dialog instgance & Central instance (if isolated from DB). It exists only on DB instance.

Application server has oracle client installed on it where tnsnames.ora exists which has the DB server information and it connect to DB.

Regards,

Sachin Rane.

[Former Member · Accepted solution]

Hi Sachin,

Thanks for the information.

It means Updates made by dialog instance get updated directly in database.Pleas confirm one more thing as you told by information in tnsnames.ora dialog instance do update in database,So is it done by simple network connection or there is any role of SAP in it.

Shivam

[Former Member · Accepted solution]

Hi Shivam

SAP has only one database connected to it..

All your application servers are connected to the central Instance and they dont have a seperate database.

When you start up an R/3 System, each application server registers its work proceses with the database layer, and receives a single dedicated channel for each. While the system is running, each work process is a user (client) of the database system (server). You cannot change the work process registration while the system is running. Neither can you reassign a database channel from one work process to another. For this reason, a work process can only make database changes within a single database logical unit of work (LUW). A database LUW is an inseparable sequence of database operations.Consequently, a work process must open a separate database LUW for each dialog step. The work process sends a commit command (database commit) to the database at the end of each dialog step in which it makes database changes. These commit commands are called implicit database commits, since they are not explicitly written into the application program.

Hope this helps

Rohit

[Former Member]

Shivam,

Please find more info about listner in the link below.

[http://download-east.oracle.com/docs/cd/B10501_01/network.920/a96580/listener.htm]

Hope this helps.

Manoj