Explained: SMF Records

A batch job ran overnight and consumed three times its usual CPU. A CICS transaction that normally completes in 12 milliseconds is suddenly taking 200. A user account was used to access a sensitive dataset at 3am. A DB2 tablespace is approaching its storage limit. None of these events sent an alert. Nobody was watching at the time. But every one of them left a record. Because on z/OS, almost everything that happens is written down. That writing-do… Read More

Explained: CICS Storage Management

It starts as a performance problem. Response times climb. Tasks start queuing. Then a message appears on the operator console: DFHSM0133 CICS is under stress (short on storage above 16MB) . New transactions are refused. The region grinds to a halt and has to be recycled. Short on storage is one of the most disruptive CICS failures in production, and unlike most failures it builds gradually. A storage leak in one transaction, a DSA limit set too co… Read More