Enterprise Server LOCKDB

The LOCKDB feature replaces the functionality of the Enterprise Server Cluster Global Lock Manager (GLM). A LOCKDB is a group of MFDBFH enabled enterprise server regions where the locking mechanism is orchestrated by the MFDBFH layer.

Members of a LOCKDB group do not have to be connected by an Intersystem Communication (ISC) link, this used to be the case for GLM configured systems.

Any locks (ENQs) for CICS, JES, IMS, and so on, are processed by MFDBFH.

Configuration

Setting up a DBLOCK group requires the following configuration. The LOCKDB feature mechanism is based on an MFDBFH setup. See Micro Focus Native Database File Handling and Enterprise Server Region Database Management for more information. Once MFDBFH has been configured, you need to set the ES_LOCKDB environment variable to the name of a region database for each enterprise server region which is to be part of the LOCKDB group. For example, to configure LOCKDB membership for two enterprise server regions, one called LOCKDB1M and the other called LOCKDB2M, add the following entries in their MFDBFH.cfg file:

<dsn name="SS.LOCKDB1M.REGION" type="region.cas" region="LOCKDB1M" feature="all" connect="db=LOCKDB;uid=xxxx;pwd=yyyy"/>

<dsn name="SS.LOCKDB2M.REGION" type="region.cas" region="LOCKDB2M" feature="all" connect="db=LOCKDB;uid=xxxx;pwd=yyyy"/>

For the first enterprise server region set the following environment variable:

ES_LOCKDB=LOCKDB1M

For the second enterprise server region set the following environment variable:

ES_LOCKDB=LOCKDB2M

JCL Submission

The sequence of the lock processing on JCL submission is the same as the previous Enterprise Server Cluster sequence. See JCL Submission for more information.

Lock Processing

The current lock list can be monitored and verified using ESMAC. For a CICS and JES enabled enterprise server region. In the left pane, from the Resources list, select Active, and then click Locks. This will display a list of active locks.

Note: The CASLOCK command cannot be used for a LOCKDB group.

Resource Name List Support

The Resource Name List (RNL) is an IBM mainframe method used by Global Resource Serialization (GRS) to identify resource scope. Of all the RNL functions, only those that are essential for identification of a SYSZDSN lock scope have been implemented. The support of RNL in a LOCKDB group is identical to Enterprise Server Cluster support. The RNL file can be a database controlled file.

Startup Sequence

In a LOCKDB group, the first enterprise server region must be cold started. For example, in a LOCKDB group consisting of two regions, the firsts region must be started as follows:

casstart -rLOCKDB1M -S:C

Once the first region has been cold started, you can start subsequent regions as follows:

casstart -rLOCKDB2M

Warning: Performing a cold start on subsequent regions will result in unexpected behavior.

VSAM Shareoptions

VSAM shareoptions are supported in a LOCKDB group.