Using the journaling facility

This section describes the HCI's extensive journaling (logging) facility. Every online system requires a method for recording what has occurred within that system in order that problems can be researched later. The journaling facility is a separate task within the HCI. This task is responsible for writing records to the current journal data set. Additionally, this task is responsible for allocating, deallocating, opening, and closing the journal data sets as necessary. Any number of individual journal data sets can be configured into the HCI although only one of them is allocated and opened at a time. Each of these is a VSAM ESDS, and is usually defined with no secondary extents.
One journal is active at a time. The first one specified in the configuration member (see <HCICNJCB Element) is dynamically allocated and opened. Journal records are written to this data set. When it fills, or upon an operator command, this data set is closed and dynamically deallocated. The next data set in the list is then allocated and opened, and journaling continues.
When the last journal in the list has been filled, the first one is again allocated and opened. In order to preserve journal data, ensure that the specified number and size of journal data sets is large enough to allow journaling to continue while the batch journal print or journal unload is run.

Allocating and Initializing Journal Data sets

The following code block shows an example of executing IDCAMS to create a journal data set. Replicate the control statements in this example to create more than one VSAM ESDS.

JCL to Allocate Journal data sets

Initialize the journal whenever its contents are no longer of interest. JCL to initialize a journal data set follows:

JCL to Initialize Journal data sets

Replace the DSN for the journal by the name used at your installation.

This section describes the HCI's extensive journaling (logging) facility. Every online system requires a method for recording what has occurred within that system in order that problems can be researched later.

The journaling facility is a separate task within the HCI. This task is responsible for writing records to the current journal data set. Additionally, this task is responsible for allocating, deallocating, opening, and closing the journal data sets as necessary.
Any number of individual journal data sets can be configured into the HCI although only one of them is ever allocated and opened at a time. Each of these is a VSAM ESDS, and is usually defined with no secondary extents.

One journal is active at a time. The first one specified in the configuration member (see <HCICNJCB Element) is dynamically allocated and opened. Journal records are written to this data set. When it fills, or upon an operator command, this data set is closed and dynamically deallocated. The next data set in the list is then allocated and opened, and journaling continues.
When the last journal in the list has been filled, the first one is again allocated and opened. In order to preserve journal data, ensure that the specified number and size of journal data sets is large enough to allow journaling to continue while the batch journal print or journal unload is run.

Allocating and Initializing Journal Data sets

The following code block shows an example of executing IDCAMS to create a journal data set. Replicate the control statements in this example to create more than one VSAM ESDS.
JCL to Allocate Journal data sets

Initialize the journal whenever its contents are no longer of interest. JCL to initialize a journal data set follows:
JCL to Initialize Journal data sets

Replace the DSN for the journal by the name used at your installation.