Defining an FDBR region

Fast Database Recovery (FDBR) provides quick access to shared database resources in a sysplex environment that might otherwise be locked by a failed IMS until the failed IMS is restarted.

The FDRMBR= keyword in the DBC and IMS startup procedures identifies the FDBR region to the IMS PROCLIB data set with a two-digit suffix (FDRMBR=xx). The IMS PROCLIB data set member is DFSFDRxx.

The DFSFDRxx member specifies the options used by FDBR. The IMS PROCLIB data set can contain multiple instances of DFSFDRxx, but each DFSFDRxx member in the IMS PROCLIB data set must have a unique, two-digit suffix. FDBR, IMS, or DBC procedures identify which DFSFDRxx member to use.

The FDR procedure executes an FDBR region. The FDR procedure is like those used to define IMS systems (for example, the IMS procedure or the DBC procedure). FDBR is supported in DBCTL and DB/DC environments.

Two parameters, CSAPSB and DLIPSB, in the FDR procedure have a different result than when they are specified for the IMS and DBC procedures. When the FDR procedure specifies CSAPSB and DLIPSB, the sum of their values defines the PSB pool size. When PSB is also specified, the larger value (PSB or the sum of CSAPSB and DLIPSB) is used.

Both the 64-bit pools and non-resident 31-bit pools in IMS active systems and their associated FDBR and XRF alternate systems must have identical contents. Any parameters and values that you specify on the active IMS system must be the same on the alternate IMS system. For example, the parameters specified in the DFSVSMxx, DFSDFxxx, and DFSPBxxx IMS PROCLIB data set members must be the same, and the sizes of the PSB and DMB pools must be the same.