Identify VSAM data sets with excessive CA/CI splits
VSAM data sets undergo CI and CA splits as they are updated and records are added or inserted. This behavior is not always a bad thing, however for some data set update patterns it can cause excessive processing and I/O.
Note: You can also use the CA/CI Split Summaries from the Dataset
Attribute Summary workspace to see the data sets with the largest number of
splits across the entire enterprise, rather than limited to defined groups.
To monitor for this condition, perform the following steps:
- Define a group encompassing the VSAM data sets that you know do not experience high split rates.
- Create a Situation to generate a warning alert when any data set in that group exceeds the threshold.
- Using Action or Workflow you can also automatically issue a command that would be trapped by, for example, AOC to cause the data set in question to be REPROed and reDEFINEd to eliminate the splits.
Assuming that you have identified and grouped the VSAM data sets that you want to monitor, create a situation as follows:
- Right-click the Dataset Group Summary node in the navigation pane.
- Click Situations in the pop-up menu. The Situations for - Dataset Group Summary dialog box is displayed.
- Click Create new Situation icon (
) to access
the Create Situation dialog box. - Enter the name and description of your new situation.
- Click OK to access the Select condition dialog box.
- Select S3_Dataset_Group_Details in the Attributes Group column.
- While pressing the Ctrl key, select both CI Splits and CI Splits in the Attribute Item column.
- Click OK to return to the Situations for - Dataset Group Summary dialog box.
- In the Formula tab, enter appropriate values in the fields. Change the operators to Greater than (>) and enter the value 8 for CA Splits and 4 for CI Splits.
- Click Apply.
- To view the formula, click
in the right-hand side of the Situation
editor panel. - Select the Distribution tab.
- Add the appropriate managed systems to the Assigned systems list for this situation.
- Click Apply and OK to complete
the definition your new situation and close the dialog box.
Whenever a excessive CA/CI splits exist, this situation is triggered and correction action can occur automatically.
Figure 1. Creating a situation for a data set group
for VSAM attributes workspace