Management collection objects
Collection Services stores data for each collection in a single collection object from which you can create as many different sets of database files as you need. This introductory topic explains the management collection object, when it is created, and how the available Collection Services settings affect these objects.
A management collection object (also known as *MGTCOL) serves as an efficient storage medium to hold large quantities of performance data. Once you have configured and started Collection Services, performance data is continuously collected and stored in these objects. Then, when you need to work with performance data you can use the data that is stored in these objects to populate performance database files.
- *PFR (detailed data)
*MGTCOL objects that have the *PFR attribute can become quite large. Their size depends on the number of active jobs in the system, performance metrics being collected, and the collection interval. Data in this type of object support the IBM® Performance Management for Power Systems™ (PM for Power Systems) performance metrics and reflect all of the requested system performance data. The Location to store collections field that is located on the Collection Services Properties window displays the library in which the *PFR objects are located. The job QYPSPFRCOL collects and stores this data in this object.
The collection is cycled (a new *PFR object is created) at least once in a 24 hour period and the QYPSPFRCOL job writes the performance data into the new object. You can schedule this to happen more frequently.
When PM for Power Systems is running, the *PFR objects are placed in the QMPGDATA library. If you are not using PM for Power Systems, then the *PFR objects are placed in the QPFRDATA library. These are default settings.
Note: If you use the Create Database Files Now option you can specify a different library, however this does not change the default setting. All subsequent files will be written to the QMPGDATA (or the QPFRDATA) library.- *PFRDTL (graph data)
Graph history and system monitors use *MGTCOL objects that have the *PFRDTL attribute. These objects are stored in the QMGTC2 library. The *PFRDTL object supports second and third level detail for the top twenty uses of the metric and the data retains the same interval by which it was collected.
The collection is cycled (a new *PFRDTL object is created) at least once in a 24 hour period and the job QYMEPFRCVT writes the data to a new object. The naming convention for *PFRDTL objects is Q0yyddd00, where yy is the year and ddd is the Julian day of the year. For best results when using the graph history function, you should retain a minimum of seven days of *PFRDTL objects.
- *PFRHST (summary data)
Graph history also uses *MGTCOL objects that have the *PFRHST attribute. These objects are stored in the QMGTC2 library. When the collection is cycled, the QYMEARCPMA job adds the data to the existing *PFRHST object. No detail data or properties data is available. You must start PM for Power Systems to enable the summary data fields. The default retention period is one month. The summary data is summarized in one-hour intervals and does not support second and third level details.
Setting the retention period
- From the System i® Navigator, expand .
- Right-click Collection Services and select Properties.
Viewing collection objects
Viewing collection objects through System i Navigator
You can use System i Navigator to view *MGTCOL objects with the *PFR attribute.
From the System i Navigator, expand .
You can also use this method. From the System i Navigator, expand .
Each object that is listed under the Collection Name is a different management collection object. You can right-click the object to see its status and data summary.
Viewing collection objects through Character-based interface
WRKOBJPDM LIB(QMGTC2) OBJTYPE(*MGTCOL)