Collecting JES3 Performance Information Data (IXZXIXPI Macro)

Resource monitoring products such as Resource Measurements Facility (RMF) need to be aware of any JES3 delays that impact performance of job processing or the JES3 subsystem. This data is not maintained by JES3, but rather collected by JES XCF on its message queues. Therefore, when running JES XCF in a JES3 environment, you might find it necessary to access and extract data from the JES XCF message queues.

JES XCF provides macro IXZXIXPI as its interface to the JES XCF message queues. When you issue IXZXIXPI, you must:

Obtain storage for the performance information data stream area that JES XCF uses to contain the information it extracts from its message queues.
Identify the name of the field or a register that contains the address of the performance information data stream. (PIDS= parameter)
Identify the name of the field or a register that contains the size of the performance information data stream area specified on the PIDS= parameter (PIDSSIZE= parameter). If the size of the area is too small, JES XCF returns the correct size requirement in this field.
Provide the group token that identifies your XCF member. (GROUPTOKEN= parameter)

JES XCF returns the JES3 processing data in key-length data (KLD) format. Figure 1 shows an example of this data stream.

Figure 1. Example JES3 Performance Data Returned by IXZXIXPI

1 2  3     6  7 8  9     12 13   15   17    20 21   24  25   27    30
0001 00000034 0002 00000002 0138 0003 00000004 00000001 0004 0000001C
31   33    36 37   39   41    44 45 46   48    51 52
0005 00000002 0298 0006 00000001 17 0007 00000001 00

Byte: Meaning
1 - 2: Key indicating the beginning of the data stream (1)
3 - 6: Length of the data stream (34)
7 - 8: JES ASID key (2)
9 - 12: Length of ASID (2)
13 - 14: ASID value (138)
15 - 16: ‘Number of delays’ key (3)
17 - 20: Length of ‘number of delays’ (4)
21 - 24: Number of delays (1)
25 - 26: Delay entry key (4)
27 - 30: Delay entry length (1C)
31 - 32: Requestor's ASID key (5)
33 - 36: ASID length (2)
37 - 38: ASID value (298)
39 - 40: Request type key (6)
41 - 44: Request type length (1)
45: Request type (17)
46 - 47: Request subtype key (7)
48 - 51: Request subtype length (1)
52: Request subtype (0)

The performance information data stream mapping macro, IXZYPIDS, maps the returned keys. Refer to z/OS MVS Data Areas, Vol 5 for a description of that mapping.