01 - JES3

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Job Entry SubsystemJES3

Paul Rogers

[email protected]

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What is a Sysplex

z/OSSC01 SC02 SC03 SC04 SC05 SC06

SC07

SC08

SC09

SC10

SC11

SC12

SC13

SC14

SC15

SC16

SC17

SC32

SC31

SC30

SC29

SC28

SC27

SC26

SC25

SC24

SC23

SC22 SC21 SC20 SC19 SC18

Coupling Technology

Cache

List

Locks

Cache

List

Locks

Sysplex Timer

Sysplex

CFRM

XCF XES

Couple Dataset

JES3JESXCF

GRS

XCFAS

JES3 Spool

WLM APPC

STCTSO

BATCH

OMVS

JES3SYSOUT

Support

Server time

Protocol (STP)

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JES3 LPAR Sysplex - MULTISYSTEM

PLEXCFG=MULTISYSTEM in IEASYSxx parmlib member

PR/SM - Provides common time reference

CTC or CF

X

C

F

X

E

S

JES3

LPAR

(JESXCF)

uses

JES3 X

C

F

X

E

SLPAR

(JESXCF)

uses

Sysplex

CDS

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Multiprocessor JES3 Sysplex

Sysplex Timer

Coupling Facility

Couple Data Sets

CTC

Checkpoint

PLEXCFG=MULTISYSTEM

JES3 X

C

F

X

E

S

(JESXCF)uses

JES3X

C

F

X

E

S

(JESXCF)uses

LOGR ARMSysplex CFRM SFM WLM

112

2

3

4

56

7

8

9

10

11

STP timing

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INPUT

JOB

CONVERSION PROCESSING OUTPUTOUTPUT

WRITERSPURGE

PURGE

QUEUE

WRITER

QUEUE

OUTPUT

QUEUE

EXECUTION

QUEUE

CONVERSION

QUEUE

SYSOUTSYSIN

JCL

JCL & SYSIN

SYSOUT

SPOOL

DISK

JES Job Flow

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Subsystems

Subsystems - service providers

Perform defined functions on SSI requests

Functions requested by system or user routines

MVS subsystems Master subsystem - MSTR

Job entry subsystem - IBM JES2 and JES3

Other subsystems

JES Functional subsystems

Provide JES-related functions on FSI requests

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JES3 as the Primary Subsystem

Primary subsystem - JES3

System input and output - (JES3 Global)

Manage jobs and spool - (JES3 Global)

Functional subsystems - FSSOffload functions to locals and global address spaces

–Converter/Interpreter and printers

JES3 global controls

–FSS start and stop

–Scheduling and selection of work for MVS

–Operator communication

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IEFSSNxx SYS1.PARMLIB definitionSETSSI {ADD,{SUBNAME|SUB|S}=subname

[,{CONSNAME|C}=consname][INITRTN(initrtn) [INITPARM(initparm)]]

[PRIMARY({NO|YES})[START({YES|NO})]]

ssname,[initrtn[,initparm]][,PRIMARY[,NOSTART]] comments (old form)

SETSSI operator command

SETSSI {ADD,{SUBNAME|SUB|S}=subname

[,{CONSNAME|C}=consname]

,{INITRTN|I}=initrtn[,{INITPARM|P}=initparm]] }

IEFSSI authorized macro serviceIEFSSI REQUEST=ADD,SUBNAME=subname,INITRTN=initrtn

,INITPARM=initparm,INITPLEN=initplen,CONSNAME=consname

,RETCODE=retcode,RSNCODE=rsncode

Defining Subsystems

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Means of communication between:Address spaces routines and subsystem

–Request services of or pass information from

Consists of:

Control blocks - macros - routines

–SSCVT - SSVT - SSOB - SSIB - (IEFSSREQ)

Subsystem Interface - SSI

MSTR JES3 Batch TSO

user

Started

tasks

IMS

Nucleus

SQA

PLPACSA

User address spaces

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SSI Control Blocks and Routines

CVT

JESCT SSCVT

SSVTIEFSSREQ

SSCVT

SSVT

(MVS nucleus) (CSA) (CSA)

(CSA)(CSA)(PLPA)

User address space

IEFSSREQ R1

BALR

Subsystem

interface

verification

routine

Functions

that this

Subsystem

can perform

Functions

that this

Subsystem

can perform

JES3 MSTR

SSOBSSIB

Function code

requested

Subsystem name

to perform function

Function dependent

area

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SSI Request to Master Subsystem

SSVT

(CSA)

SSCVT

(CSA)

MSTR

SSOB

SSIB

IEFJSREQroutine

0 0 0 4 12 0 4 4 40 5 0 4 30 0 0 0 0

0 4 0 0 00 0 0 4 10 0 0 0 00 0 0 0 00 0 4 0 40 0 0 0 00 0 0 0 00 0 4 0 0routine ptr 1routine ptr 2

routine ptr 4routine ptr 5

SS verif. routine

0 0 0 0 0

zeros

256

byte

MSTR

15

Verify subsystem nameTo: Master subsystem

Function code: 15

(1) Check SSIB SSOB

(2) Is subsystem valid

(3) Is subsystem up

(4) Can subsystem

process request

(5) Pass control to

routine

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JES3 Global

Global processor manages jobs and resourcesFor the entire complex

Matches jobs with available resources

JES3 global manages

Processors - I/O devices - Volumes - Data sets

When resources are not available

JES3 ensures that they are before selecting the job for

processing to an initiator

Operations aid

Operator commands

Diagnostic tools

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JES Communication using JESXCF

XCF

Status

Monitoring

JESMail

JESMail

JESMail

JESXCF

JESXCF

JESXCF

SYSA

SYSB

SYSC

Sysplex

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XCF Signalling Paths

CTC device or coupling facility list structure

Defined in COUPLExx parmlib member

JES3 signalling paths can be:

Default paths - for use by all groups

Dedicated paths - for a specific group

CTC paths are one directional Requires a PATHIN and a PATHOUT

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SSI Communication - Global / local

XCF A/S

JESXCF A/S

JES3 Comm Serv

DSPsJSERV

DSQLOC

Global

XCF A/S

JESXCF A/S

JES3 Comm Serv

SSISERV

Local

Staging

Areas

CTC

or

CF

PLPA

JES3 A/S

User A/S SSI request

PLPA

PLPA

(function routine)

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1

2

3

4

5

6

7

8

910

11

12

13

16

1718

19

20

21

22

23

SYSOUT

CANCEL

JOB STATUS

EOT

JOB SELECTION

ALLOCATION

UNALLOCATION

EOM

WTO/WTORCMD PROCESSING (SVC34)

REMOT DEST VALIDITY CK

JOB DELETION

JOB RE-ENQUEUE

OPEN

CLOSECHECKPOINT

RESTART

REQUEST JOB ID

RETURN JOB ID

STEP INITIATION

DYNAMIC ALLOCATION

24

25

26

27

28

29

30

31

3234

40

53

54

56

6264

72

75

77

79

80

81

COMMON ALLOCATION

COMMON UNALLOCATION

CHANGE DDNAME

CHANGE ENQ USE ATTRIBUTE

DDR CANDIDATE SELECT

DDR CANDIDATE VERIFY

DDR SWAP NOTIFICATION

DDR SWAP COMPLETE

SVC34 COMMAND FAILWRITE TO LOG

EARLY VOLUME RELEASE

FSS/FSA CONNECT/DISCON

SUBSYSTEM VERSION

SMS TO JES3 COMMUNICATION

BDT SUBSYSTEMTRANSACTION PROCESSING

VARY PATH CALL

NOTIFY-USER MSG ROUTER

PERSISTENT JCL

SYSOUT API

ENHANCED STATUS

JES3 SSI Authorization PC

JES3 SSI Functions

SSISERV F nction Codes and

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SSISERV Function Codes andJES3 Destination Queue

128

129

130131

132

133

134

135

136137

138

139

140

141

142

143

144

145

146

147

148

149

150

MAIN SERVICE

GENERALIZED MAIN SCHED

VERIFYLOCATE

JES DATA MANAGEMENT

USER TRACK ALLOCATION

CONSOLES SVC 34

CONSOLES WTO

UNUSEDVERIFY RESPONSE

WORK TO DO DRIVER

SSICS

SSICS

ENDREQ

MODIFY DRIVER

INQUIRY DRIVER

SYSOUT INTERFACE

SYSTEM CONNECT

ALT CTC RETRY

UNUSED

STAR SHORTAGE

DYNAL-ALLOC

DYNAL-UNALLOC

151

152

153154

155

157

158

159

160161

162

DYNAL-CHG DDN

COMMUN. FROM AN FSS

CI DRIVERIOERR

FSS start

SAPI

Enhanced Status

WLM

JESMSGLocal Module Load/Call

TCPIP service

R 1414140101 00 00

0

128

(00)

(01) GMS Q-ENTRY

0500 06 07

0100 02 03

MVS SSI

CODES

JES3

Destination

CODES

Q-ENTRIES

JES3 destination queuePointed by DSQLOC in IATYTVT and SVTDSQ in IATYSVT

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JES3 Destination Queue - IATYDSQ

ECF ADDRESS

ECF MASK

FLAGs

QUEUE HEADER

QUEUE TAIL

JESXCF MAILBOX NAME

(16 bytes)

Staging Areas

DSQQST-Entry

STAR

STAR

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Function Control Table - FCT

FCT - JES3 dispatching element

An FCT represents a dispatchable unit of work in the

JES3 adrress space, or an FSS which supports JES3

nucleys services

Mapped by IATYFCT macro

Major FCTs part of JES3 nucleus - resident FCTs

Module IATGRPT contains the resident FCTs, DSP

dictionary entries, and user exit address list.

Other FCTs added to FCT chain when needed

IATXGFC macro initializes an FCT for a DSP

IATXATF macro attaches an FCT to the active FCT

chain in priority sequence.

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JES3 FCT Dispatching

JES3 tasks (TCB) dispatched by MVS - IATNUC

Multifunction monitor - MFM

–Dispatcher of JES3 functions

Active JES3 functions - FCT

JES3 functions - FCTsResident and transient

Dynamic support program - DSP

FCT function states:

–Program loading

–Executing

–Waiting to execute

–

Function complete - remove FCT

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FCT Chaining

FCTTOP

TVTRDQTP

JES3 TVTABLEFCTNEXT

FCTRDQCH

FCT entry

255 FCT Priority

FCTNEXT

FCTRDQCH

FCT entry

10

.

.

FCTNEXT

FCTRDQCH

FCT entry

254 FCT Priority

Next FCT on the Ready Queue

First FCT to be dispatched

from the Ready Queue

(Flag in FCT - FCT on Ready Queue)

READYQ

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JES3 Dispatching of a WTR FCT

MFM ofJES3

(IATGRCT)- - - - - - - - - - - - - -- - - - - - - - - - - - - -- - - - - - - - - - - - - -- - - - - - - - - - - - - -

AWAIT - Return toMFM

CONCMD

READYQ

WTR

JSS

WAIT

IATNUC

TCB

JES3 dispatched by MVS

FCTs

Examine FCT chain

- - - - - - - - - - - - - -- - - - - - - - - - - - - -- - - - - - - - - - - - - -- - - - - - - - - - - - - -

WTR DSP code

"ready"

(Readyqueue)

FCT issues MVSWAIT for SVTJ3ECB

FCTTOP

TVTRDQTP

JES3 TVTABLE

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JES3 SSVT

SVTJ3ECB

ASPECB

ASPTCB

JES3 TVTABLE

JES3 IATNUC MASTER ECB

Address of JES3MASTER ECB

Address of A(TCB)

Posting JES3 ECB

Asynchronous routines or routines

running outside JES3 address space

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Major JES3 Control Blocks

JES3 functions

FCT - Number in storage definable

–RESCTLBK,FCT=nnnn

Job related

JCT - Stored in a separate spool data set

–A JCT contains information pertinent to a single job

–JCTs are resides in a dataspace when in-storage

JQE - Size definable via OPTIONS statement

–OPTIONS,...JOBNO=(,,joblim)

RQ - Size determined by JES3 –Cell pools built at initialization and dynamically

JES3 address space

TVT - TVTABLE in JES3 nucleus

–Contains pointers to almost everything

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JES3 DSP Dictionary

Resides in IATNUC - IATGRPT

Contains resident FCT table

Contains DSP dictionary entries

Contains DSP device requirement lists

– IATYDSD macro - Add DSP to system

– IATYFCD macro - Add resident FCT

User exit address lists

Dynamic support program (DSP). Multiprogrammed system

components that are scheduled by the job segment scheduler (JSS)

and implement a specified JES3 function. A DSP can be

related to job execution, such as main service or output service,

or it can be a background utility, such as the dump job facility.

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JCT Control Block

Job Control Table (JCT) control blocks

Entry created when a job enters system

Entries in job priority order

JCT spool data set Contains a record for every job in system

Most important control block in system

Spool data set on volume is critical for restarts

JCT utility program (IATUTJCT)

Copy JCT data set to a new JCT data set

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Job Queue Element - JQE

IATGRJX - JQE/JCT access method services

IATXJCT and IATXJQE macros

JQE entries created when jobs enters the system

Contains a summary of information from a JCT entry

Contains a list of functions for job scheduling

Function is called a scheduler element

Contains status of function - active or waiting to be

scheduled

Mapped by IATYJQE

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RESQUEUE Control Block - RQ

Created when a job becomes active

Each time a scheduler element for job becomes active

by JSS

Contains all pointers to other job control blocks

Key control block for user exits

Mapped by IATYRSQ

Resident Queue (RESQUEUE). A control block built in storageby the job segment scheduler (JSS) to represent a scheduler

element during the life of the scheduler element.

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RESQUEUE Types and Sections

6 different RQ sections - HJS7750 size

FIXED section - 416 bytes

OUTSERV section - 72 bytes

MDS section - 200 bytes GMS section - 80 bytes

CI section - 40 bytes

COMMON section - 16 bytes

4 RQ types

CI - MAIN - OUTSERV - OTHER function

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FIXED

SECTION

OUTSERVSECTION

FIXED

SECTION

OUTSERVSECTION

FIXED

SECTION

OUTSERVSECTION

FIXED

SECTION

OUTSERVSECTION

MDS

SECTION

MDS

SECTION

GMSSECTION

CISECTION

COMMON

SECTION

CIRESQUEUE

MAINRESQUEUE

OUTSERVRESQUEUE

OTHER functionRESQUEUE

RQ Control Blocks

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JES3 naming conventions

JES3 naming conventions

Module names : IAT ff xx

– ff : functional area

– xx : function performed

Module examples :

– IATISDV - IATOSDR - IATSICA

– IATISDR - IATOSSC - IATSI34

Coding macros - IATX... (except for legacy macros) Data macros - IATY...

JES3 nucleus - IATNUC

Documents

01 - JES3