Configuring the DAS on DB2 Enterprise Server Edition systems - IBM DB2 9.7 for Linux, UNIX, and Windows

The DAS is an administrative control point that performs certain tasks on behalf of the tools. There can be at most one DAS per physical computer.

In the case of an ESE instance that consists of several computers, all of the computers must be running a DAS so that the Control Center can administer the ESE instance. This DAS (db2as) is represented by the system that is present in the Control Center navigator tree as the parent of the target DB2® database instance (db2inst).

For example, db2inst consists of three nodes distributed across two physical computers or hosts. The minimum requirement can be fulfilled by running db2as on hostA and hostB.

Note:

The number of database partitions present on hostA does not have any bearing on the number of DASes that can be run on that host. You can run only one copy of the DAS on hostA regardless of the multiple logical nodes (MLN) configuration for that host.
There is one DAS required on each computer, or physical node, which must be created individually using the dascrt command. The DAS on each computer or physical node must be running so that the Task Center and the Control Center can work correctly. The ID db2as must exist on hostA and hostB. The home directory of the db2as ID must not be cross-mounted between the two systems. Alternatively, different user IDs can be used to create the DAS on hostA and hostB.

On DB2 Enterprise Server Edition for Windows, if you are using the Configuration Assistant or the Control Center to automate connection configuration to a DB2 server, the database partition server that is on the same computer as the DAS will be the coordinator node. This means that all physical connections from the client to the database will be directed to the coordinator node before being routed to other database partition servers.

On DB2 Enterprise Server Edition for Windows, creating additional DB2 administration servers on other computers allows the Configuration Assistant or Control Center to configure other systems as coordinator nodes using DB2 Discovery.

When working on DB2 Enterprise Server Edition for Windows, the DB2 Remote Command Service (db2rcmd.exe) automatically handles internode administrative communications.

The Control Center communicates with the DAS using the TCP service port 523. This port is reserved for exclusive use by the DB2 database manager. Therefore, it is not necessary to insert new entries into TCP services file.