Overview of the CSL Open Database Manager
Open Database Manager (ODBM) provides distributed and local access to IMS databases that are managed by IMS DB systems configured for either the DBCTL or the DB/TM environments in an IMSplex.
Both independently and with IMS Connect, ODBM supports various interfaces to ease the development of application programs that access IMS databases from many different distributed and local environments. The interfaces that ODBM supports include:
- IMS Universal Database resource adapter
- IMS Universal JDBC driver
- IMS Universal DL/I driver
- The ODBA interface
- The ODBM CSLDMI interface for user-written ODBM client application programs
In addition to supporting the above interfaces, ODBM provides the following functions:
- Supports one-phase commit with or without requiring z/OS® Resource Recovery Services as the sync point coordinator. If the ODBM parameter RRS=N is specified, the Database Resource Adapter (DRA) is used to communicate with IMS.
- Routes incoming database requests to IMS systems based on alias names. Alias names
for IMS systems are defined to
ODBM on the CSLDCxxx PROCLIB member and specified on incoming database
requests by the client application programs.
If the client application program does not specify an alias name on a database access request, ODBM routes the request among multiple IMS systems by using a round-robin method of distribution, in which ODBM routes each incoming request to the active IMS systems that are defined to ODBM.
- Enables ODBM client application programs to access databases from other logical partitions within an IMSplex
- Protects IMS control regions from the unexpected termination during DL/I processing of z/OS application programs that use the ODBA interface through ODBM.
- Functions as an RRMS resource manager capable of participating in RRS controlled sync point processes for ODBA applications that are configured to use ODBM.
- Functions as the resource manager and issues the necessary calls to RRS for single-phase commit processing for local RRS transactions.
- Functions together with IMS Connect as a complete Distributed Relational Database Architecture (DRDA) target server for client application programs that use the DRDA specification.
Because ODBM and IMS Connect support DRDA, you can develop your own DRDA source application server that communicates with IMS by using the distributed data management (DDM) Architecture commands that are a part of the DRDA specification.
ODBM leverages the z/OS System Management Facility (SMF) to perform logging of ODBM accounting information, such as CPU usage, and its retrieval. The logging of the ODBM address space is activated when the optional parameter LOGOPT=ACCOUNTING is specified in the ODBM initialization member, CSLDIxxx.
ODBM runs in a Common Service Layer (CSL) address space and is an optional IMSplex component. ODBM uses the Structured Call Interface (SCI) services of the CSL for communication and Operations Manager (OM) services of the CSL for command processing.
One ODBM instance must be defined in the IMSplex to use ODBM functions. Each z/OS image can have more than one ODBM. If multiple instances of ODBM are defined in the IMSplex, any ODBM instance can perform work from any z/OS image in the IMSplex.
The following figure shows an overview of an IMS configuration that includes ODBM.
