Configuring DRDA data sources

The federated server provides connectivity to data sources by using the open DRDA protocol. This support is equivalent to that provided by the Db2 Connect server.

Before you begin

In addition, for two-phase commit, the federated server interacts with each data source using the industry-standard XA model.

Before you begin

Restrictions:
  • Not all data sources support XA over DRDA natively. For those that do not, such as Db2® for z/OS® and Db2 for IBM® i, the federated server uses the syncpoint manager (SPM). The syncpoint manager performs a mapping between the XA and non-XA two-phase-commit flows that all Db2 servers support. When federated two-phase commit access is provided by using the syncpoint manager, not all XA semantics are supported because of incompatibilities between federated support and the syncpoint manager. For example, transactions cannot be nested. All transactions must be committed or rolled back before starting a new transaction.
  • In an XA DRDA two-phase inbound connection to Federation Server, if the inbound connection uses an external multi-transport transaction manager, a Db2 for z/OS client can perform federated two-phase commit with the following configurations:        
    • Use a Db2 Connect instance as the syncpoint manager (SPM). You should separate Federation Server and Db2 Connect into separate instances.
    • Enable connection concentrator on the Db2 Connect instance.
  • Federated two-phase commit supports Db2 for z/OS, but Db2 for z/OS does not allow a SAVEPOINT statement to be issued in a federated two-phase commit transaction.
  • In a Db2 coordinated transaction, a Db2 for z/OS client can perform a federated one-phase update over a DRDA two-phase inbound connection. However, such an update cannot be completed over an XA DRDA two-phase inbound connection. Nor can a mix of one-phase and two-phase updates over a DRDA two-phase inbound be completed.
  • The XA_OPEN_STRING_OPTIONS server option is not supported for DRDA data sources. If you use the option, an SQL1881 error is returned.
Requirements:
  • For those data sources that support XA by using SPM rather than by supporting XA natively, ensure that the SPM_NAME and SVCENAME parameters in the database manager configuration are properly set to their defaults.

About this task

Procedure

To configure a DRDA data source:

Procedure

Run the CREATE SERVER, ALTER SERVER, or SET SERVER statement with the DB2_TWO_PHASE_COMMIT option set to Y.

The DRDA wrapper automatically generates the following XA OPEN string for DRDA data sources:

DB=dbname,UID=uid,PWD=password,TPM=FDB2,HOLD_CURSOR=T