Upload
ggddggddggdd
View
6.169
Download
14
Tags:
Embed Size (px)
DESCRIPTION
Citation preview
Parallel Sysplex Implementation
Parallel Sysplex CenterPoughkeepsie, NY USA
Trademarks
The following terms used in this presentation are trademarks of the IBM Corporation
ƒ ACF/VTAMƒ CICS/ESAƒ DB2ƒ DFSMS/z/OSƒ ESA/390ƒ ESCONƒ ES/9000ƒ IBMƒ z/OS/ESA SPƒ PR/SMƒ PS/2ƒ RACFƒ S/390ƒ SYSPLEX TIMERƒ VM/ESAƒ VTAM
Overview– Pre-Sysplex Multisystem Applications
z/OS Parallel Sysplex–Components/Terminolgy–Multisystem Sysplex Requirements–IBM 9037 Sysplex Timer–XCF Signalling Requirements–XCF Sysplex Couple Data Sets–GRS in a Sysplex–Parallel Sysplex Resource Managers–Policies
Agenda
Parallel Sysplex Implementation StepsSummaryParallel Sysplex Extensions
–z/OS Logger–Automatic Restart Manager (ARM)–Sysplex Failure Manager (SFM)
Agenda (cont.)
Pre-Sysplex Multisystem Applications
CICS IMS JES2
VTAM
GRS
JES3
CONSOLES
JES2 IMS CICS
VTAM
GRS
JES3
CONSOLES
CTC
CTC
CTC
MCS MCSJES3MVS MCS
MVS
z/OS Parallel Sysplex
Multiple systems coupled together by hardware and software services that can be viewed as a single entity.
Improves: AvailabilitySystems ManagementGrowth
121
2
3
4
56
7
8
9
10
11
CouplingTechnology
Shared data
Sysplex Timer
ESCON/FICON
9672zSeries
S/390 Sysplex Components/Terminology
Sysplex A set of 1-32 z/OS systems coupled togetherusing hardware and software elements.
XCF Cross-system Coupling Facility-provides the z/OS communications services within a Sysplex.Multisystem
ApplicationAn authorized application that has functions distributed across more than one z/OS system.CTC Channel to Channel connection-direct connection between two z/OS systems (ESCON CTC, 3088).Sysplex
Couple Data Set
A data set shared by all XCF components in a sysplex. Contains XCF-related data for the sysplex.
Sysplex Timer
IBM 9037 Sysplex Timer-external clock used to synchronize the TOD clocks of the systems.
Member A specific function of a multisystem application that is defined to XCF and assigned to a group.Group A collection of related members.
Serialization The function provided by GRS that is used to serialize resources used by XCF and other users.
S/390 Parallel Sysplex Components/TerminologyParallel Sysplex
2 or more z/OS images in a Sysplex using the coupling facility to share data (up to 32)XES Cross-system Extended Services-provides the z/OS communication services to the coupling facility
Coupling Facility
Hardware element that provides high-speed caching, list processing, and locking functionsCoupling
Facility Link/Channel
High bandwidth fiber optic link that provides high speed connectivity required for data sharing between the CF and attached CPCsStructures Dynamically partitioned areas of storage within a coupling facility manipulated by z/OS/ESA system services
Data Sharing
The ability of concurrent subsystem programs to directly access and change data with integrity.Data
Sharing Group
Collection of two or more subsystems that access and share data in the coupling facility
Role of the CF
LOCKS DATA BUFFERS
DATABASE MANAGER
DATA BUFFERS
DATABASE MANAGER
z/OS Sysplex Services
Coupling Technology
REQUESTS REQUESTS
z/OS
S/390
z/OS
S/390
LocksListsCaches
LOCKS
Multi-SystemSerializationChanged Data
Multisystem Parallel Sysplex Requirements
Requirements for all systems in an z/OS Sysplex:
Be connected to a common time sourceUse the same Couple Data SetsBe in the same GRS configurationHave full connectivity to every other system in the SysplexHave unique system names within the SysplexSpecify the same Sysplex nameHave connectivity to all CFs
IBM 9037 Sysplex Timer
S0000 Main MenuTime HelpPort
sProfile
LogMaint
01/09/9009:17:23
UTCStatus changed. View log for details.F1=Help
9037 SysplexTimer Unit
(TOD) Clock Management using ETR Synchronization Mode
TOD values kept in synchronization with the Sysplex TimerNo operator intervention required to set TOD clocksExpanded availability configuration is strongly recommended
Sysplex Modes
XCF
APPLICATION
XCF
APPLICATION
XCFLocal
XCFMonoplex
XCF
CTCs
Couple Data sets
Timer
GRS
APPLICATION
XCF
GRS
APPLICATIONXCF Multisystem
Otherz/OSWork
Otherz/OSWork
Otherz/OSWork
Otherz/OSWork
Couple Data sets
XCF-Multisystem Sysplex ConfigurationsXCF
XCF
GRS
GRS
APPL
APPL
Multiple Physical Processors
XCF
XCF
GRS
GRS
APPL
APPL
Multiple LPARs on a Single Processor
XCF
XCF
GRS
GRS
APPL
APPL
Multiple VM Guests
*
**Note: Sysplex Timer and CTC considerations
Processor 1
Processor 2
z/OS 1
z/OS 1
z/OS 2
z/OS 2
Full Connectivity to all systems is required– Redundant configurations are recommended
Potential configurations include:–ESCON Channels operating in CTC mode (Point-to-Point)
ƒ Channels supporting CTC communications must be paired; one operating in CTC (Type=CTC) mode and the other operating in native mode (Type=CNC)
–ESCON Channels with ESCON Directors (ESCD)ƒ Reduces the number of CTCs that must be usedƒ Allows the native ESCON channels to be used for attaching other
ESCON devices–PR/SM LPARs with ESCON Multiple Image Facility
ƒ Using shared channels further reduces channel requirementsƒ Signalling structures
z/OS Sysplex Connectivity
XCF CTC Signalling Requirements
Outbound Inbound
Inbound Outbound
System A
System BConnecting Link
At least one connecting link must be defined between each system in the Sysplex - A connecting link consists of a pair of inbound-outbound signalling paths between systems - Signalling paths are uni-directional - Recommended minimum is 4 signalling paths between each system (2 inbound and 2 outbound)
XCF Logical connections:
XCF CTC Signalling Requirements . .
Outbound Inbound
Inbound Outbound
Connecting Link
XCF Logical connections:
ESCON CTC Physical connections
600 100
601 101
SYS1 SYS2
XCF
XCF
PATHOUT (600)PATHIN (601)
PATHIN (100)PATHOUT (101)
SYS1 SYS2 ctc cnc
System 1 System 2 CHPID 03 CHPID 22
System 1 I/O Definition
System 1 System 2
CHPID PATH=((03)),TYPE=CTCCNTLUNIT CUNUMBR=600,PATH=((03)), UNITADD=(00,2)),UNIT=SCTCIODEVICE ADDRESS=(600,2),CUNUMBR=(600), UNIT=SCTC
System 2 I/O Definition
CHPID PATH=(22)),TYPE=CNCCNTLUNIT CUNUMBR=100,PATH=((22)), UNITADD=(00,2)),UNIT=SCTCIODEVICE ADDRESS=(100,2),CUNUMBR=(100), UNIT=SCTC
XES signalling provides the ability to establish XCF signalling connectivity through the coupling facility
– In addition to, or instead of, the existing signalling capability using CTC links
XES automatically configures paths to all systems using a common CF list structure
–Defining a coupling facility list structure as an outbound definition for XCF will cause an XCF signalling path to be established with every other system that has the structure defined as an inbound path
–A coupling facility list structure can be defined and be used for both outbound and inbound XCF signalling paths
XES Signalling Structures
InstallationUnidirectional, point-to-point; Minimum CTC paths to
provide full connectivity for 8 system Sysplex is 56 (8*(8-1)); 112 for redundancy
Bidirectional, one-to-many; one coupling facility list structure can support more than an 8 system Sysplex; 2 for redundancy
AdministrationPARMLIB, I/O Definition, Shared COUPLExx member not
practical because of CTC addressesPARMLIB, Administrative policy, shared COUPLExx
member possible if all systems share the same list structure(s) and all other XCF parameters are the same
RecoveryManualXES and Coupling Facility initiated
XCF CTC
XES Signalling
XES Signalling
XES Signalling
XCF CTC
XCF CTC
XCF CTC Signalling versus XES Signalling
COUPLE SYSPLEX (PLXM) PCOUPLE (SYS1.XCF#PLXM.CDS01) ACOUPLE (SYS1.XCF#PLXM.CDS02)
PATHIN STRNAME(IXCSTR1) PATHOUT STRNAME(IXCSTR2)
Signalling Definitions
Coupling Facility
CTC COUPLE SYSPLEX (PLXM) PCOUPLE (SYS1.XCF#PLXM.CDS01) ACOUPLE (SYS1.XCF#PLXM.CDS02)
PATHIN DEVICE(E40,E41) PATHIN DEVICE(890,891)
PATHOUT DEVICE(100,101) PATHOUT DEVICE(200,201)
XCF Sysplex Couple Data Set
Required for XCF-Monoplex or XCF-Multisystem Sysplex modesAn alternate couple data set may be specifiedCouple data set(s) must be shared by all systems in the SysplexSome information kept in the couple data set includes:
–Names of the systems in the Sysplex–Status of the systems in the Sysplex–A system status field that is periodically updated by each system to indicate its "health"
–Names of groups and members–Member status for members using permanent status recording
All systems in the Sysplex will go in wait state, if couple data set(s) are not usable
Defined in PARMLIB; May be added or removed using SETXCF
Shared data repository for the systems in a Sysplex
XCF Sysplex Couple Data Set . . .
Avoid placing Couple Data set on volume with high use data setsAvoid a volume that has the RESERVE macro issued against itNormal I/O activity - Status Updates - 2 I/Os every 3 seconds per system in Sysplex
Additional I/O activity–I/O to the Couple Data Set for every action message in Sysplex (for example, WTOR)
–Modifications to the Sysplex (for example, activation of a new group)–During recovery
GRS Multisystem (Global) serialization is required for XCF-Multisystem Sysplex mode
In a multisystem Sysplex GRS can use lock structure to manage GRS configuration. Benefits:–Improved Performance
All systems in the Sysplex must be in the same GRS configuration
Global Resource Serialization in a Sysplex
z/OS z/OS
RSA
RNLs RNLs
CTC
GRS
GRS
XCF
XCF
z/OS Parallel Sysplex Resource Manager Policies
Sysplex-wide administrative policies–Automated, system-managed goals–Changes communicated to all systems in the sysplex–Dynamically changed using commands–IPL not required
z/OS Coupling Facility Resource Manager (CFRM) Policyz/OS Sysplex Failure Mangement (SFM) Policyz/OS Workload Manager (WLM) Policyz/OS Automatic Restart Manager (ARM) Policyz/OS Logger Inventory
Parallel Sysplex Implementation Steps
Planning for a z/OS Parallel Sysplex
Review:
–Sysplex Implementation Requirements
ƒ z/OS Sysplex and S/390 Parallel Sysplex
ƒ Software/Hardware
–Network Considerations
–Potential Applications
–Operations Changes
–Testing Requirements
Customization Tasks for Parallel Sysplex
ƒ SYS1.PARMLIBIEASYMxx
SYSNAME, SYMDEF definitions
IEASYSxxSYSNAME, GRS, GRSCNF, CLOCK, PLEXCFG, CON, COUPLE
CLOCKxxGRSCNFxxGRSRNLxxCONSOLxxCOUPLExx
SYSPLEX name, COUPLE data sets, Signalling paths
ƒ Format Couple data setsƒ IPL with new configurationƒ Bring other systems into the SYSPLEX
IEASYMxx Member of PARMLIB
SYSDEFSYSCLONE(&SYSNAME(3:2))SYSPARM(PS)SYMDEF(&SYSR1='BMRS11')SYMDEF(&SYSR2='&SYSR1(1:5).2')SYMDEF(&GRSPARM=‘STAR’)SYMDEF(&COUPLE=‘PS’)
SYSDEF HWNAME(AB02) LPARNAME(Z021) SYSNAME(ZMB0) SYMDEF(&APPN='8B') SYMDEF(&SSCPID='811') SYSDEF HWNAME(AB01) LPARNAME(Z011) SYSNAME(ZMB1) SYMDEF(&APPN='8C') SYMDEF(&SSCPID='812')
IEASYSxx Member of PARMLIB
PLEXCFG=ANY,GRS=&GRSPARM,GRSRNL=PS,CON=PS,CLOCK=PS,COUPLE=&COUPLE,
CLOCKxx Member of PARMLIB
ETRMODE YESETRZONE YESETRDELTA 10TIMEZONE E.08.00.00
GRSRNLxx Member of PARMLIB
/* System EXCLusion List */ RNLDEF RNL(EXCL) TYPE(SPECIFIC) QNAME(SYSDSN) RNAME(SYS1.LOGREC)
/* System INCLusion List */ RNLDEF RNL(INCL) TYPE(GENERIC) QNAME(SYSDSN)
/* System CONversion List */ RNLDEF RNL(CON) TYPE(PATTERN) QNAME(*)
SYSPLEX provides the capability to dynamically change the GRS Resource Name List
Implementing Parallel Sysplex
ƒ Format SYSPLEX couple data setsUpdate COUPLExx for signalling paths
ƒ Format other couple data setsCoupling Facility Resource Management (CFRM)Sysplex Failure Management (SFM)Workload Management (WLM)Automatic Restart Management (ARM)
ƒ Define CF structuresXCF/XES signallingVTAM JES2 RACFIRLM LOGGERothers......
Sysplex Couple Data Set
Required for:XCF-Multisystem and XCF-Monoplex
Must be shared by ALL systems in sysplexAvoid placing on busy volumesDefine primary and alternate
Alternate is optional but recommendedDefined by IXCL1DSU batch utility
IXCSYSPF in SYS1.SAMPLIB
Control Statement:
DEFINEDS DSN(SYS1.XCF#PLXM.CDS01) VOLSER(BMCD01) SYSPLEX(PLXM) MAXSYSTEM(6) CATALOG DATA TYPE(SYSPLEX) ITEM NAME(GROUP) NUMBER(20) ITEM NAME(MEMBER) NUMBER(50)
COUPLE SYSPLEX (PLXM) PCOUPLE (SYS1.XCF#PLXM.CDS01) ACOUPLE (SYS1.XCF#PLXM.CDS02)
PATHIN STRNAME(IXCSTR1) PATHIN DEVICE(E40,E41) PATHIN DEVICE(890,891) ... ...
PATHOUT STRNAME(IXCSTR1) PATHOUT DEVICE(100,101) PATHOUT DEVICE(200,201) ... ...
Signalling Definitions - COUPLExx
Coupling Facility
CTCs
Coupling Facility Resource Manager Policy
Coupling Facility Resource Manager (CFRM) policy
Defines Coupling Facilities (CFs) to be usedƒ Type of Coupling Facilityƒ CPCIDƒ Sequence Numberƒ etc.....
Defines structures and their placement in the CFsƒ Preference List, Exclusion List
Batch Administrative Utility
Define CFRM Couple Data Set
ƒ IXCCFRMF member in SYS1.SAMPLIBExecute IXCL1DSU batch utility Alternate CFRM couple data set is HIGHLY recommended
Control Statements:
DEFINEDS SYSPLEX(PLXM) DSN(SYS1.CFR#PLXM.CDS01) VOLSER(BMCD02) CATALOG DATA TYPE (CFRM) ITEM NAME(POLICY) NUMBER(6) ITEM NAME(CF) NUMBER(5) ITEM NAME(STR) NUMBER(20) ITEM NAME(CONNECT) NUMBER(32)
Define CFRM Policy
ƒ IXCCFRMP member in SYS1.SAMPLIB
Execute IXCMAIPU administrative data utility CFRM couple data set must be pre-formatted
IXCMAIPU administrative data utility is used to addupdate, or delete policy data Structure sizes must be estimated
CFSizer has recommendations
RACF protect IXCMAIPUResource name ‘MVSADMIN.XCF.CFRM' in FACILITY class
DATA TYPE(CFRM) REPORT(YES) DEFINE POLICY NAME(PLXM) REPLACE(YES) CF NAME(C033) TYPE(002064) MFG(IBM) PARTITION(3) SEQUENCE(000000019B1A) CPCID(00)
CF NAME(C021) TYPE(002064) ... ... STRUCTURE NAME(IXCPATH1) SIZE(16316) PREFLIST(C033,C021) REBUILDPERCENT(1) STRUCTURE NAME(ISTGENERIC) SIZE(10000) PREFLIST(C033,C021) STRUCTURE NAME(ISTMNPS) SIZE(12288) PREFLIST(C021,C033) STRUCTURE NAME(IXCPATH2) SIZE(16316) PREFLIST(C021,C033) EXCLLIST(IXCSTR1)
CFRM Policy Control Statements
Example:
C033
C021
IIXCPATH1
ISTGENERIC
ISTMNPS
IXCPATH2
Activating CFRM Policy
Make CFRM Couple Data Set available to z/OS:
SETXCF COUPLE,PCOUPLE=SYS1.CFR#PLXM.CDS01,TYPE=CFRMSETXCF COUPLE,ACOUPLE=SYS1.CFR#PLXM.CDS02,TYPE=CFRM
Activate CFRM Policy:
SETXCF START,POLICY,POLNAME=PLXM,TYPE=CFRM
Only one member of the sysplex needs to activate the policy
Update COUPLExx Member of PARMLIB
COUPLE SYSPLEX(&SYSPLEX) PCOUPLE(SYS1.XCF#&SYSPLEX..CDS01) ACOUPLE(SYS1.XCF#&SYSPLEX..CDS02)
DATA TYPE(CFRM) PCOUPLE(SYS1.CFR#&SYSPLEX..CSD01) ACOUPLE(SYS1.CFR#&SYSPLEX..CDS02)
PATHOUT STRNAME(IXCSTR1) PATHIN STRNAME(IXCSTR2)
z/OS Workload Manager Policy
z/OS Workload Manager (WLM) Policy
Performance goalsNot parameter driven
ƒ Replaces SRM IPS & ICSƒ Business importance
ISPF Dialogs to define
Define WLM Couple Data Sets
ƒ IWMFTCDS member in SYS1.SAMPLIBExecute IXCL1DSU batch utility Alternate WLM couple data set is strongly recommendedDefine resource name MVSADMIN.WLM.POLICY in the FACILITY class of RACFUse PERMIT to allow access
Control Statements:
DEFINEDS SYSPLEX(PLXM) DSN(SYS1.WLM#PLXM.CDS01) VOLSER(BMCD01) CATALOG DATA TYPE (WLM) ITEM NAME(POLICY) NUMBER(6) ITEM NAME(WORKLOAD) NUMBER(35) ITEM NAME(SRVCLASS) NUMBER(100)
Activating WLM Policy
Make WLM Couple Data Set available to z/OS:
SETXCF COUPLE,PCOUPLE=SYS1.WLM#PLXM.CDS01,TYPE=WLMSETXCF COUPLE,ACOUPLE=SYS1.WLM#PLXM.CDS02,TYPE=WLM
Activate WLM Service Policy:
VARY WLM,POLICY=wlm_policy_name
Don't forget to update COUPLExx member
Sysplex Failure Management Policy
Sysplex Failure Mangement (SFM) policy
Automates Sysplex recovery actions:ƒ Loss of connectivityƒ System status update missingƒ Storage Reconfiguration
Batch Administrative Utility
Sysplex Failure Management
z/OS A
VTAM NNJES2CMC
962
Example
z/OS BVTAM ENJES2Test onlines
390 micro
VTAM ENJES2 Prod Onlines
390 micro
z/OS C
Sysplex Failure Management
z/OS A
VTAM NNJES2CMC
962
Example
z/OS BVTAM ENJES2Test onlines
390 micro
VTAM ENJES2 Prod Onlines
390 micro
z/OS C
Sysplex Failure Management
z/OS A
VTAM NNJES2CMC
962
Example
z/OS BVTAM ENJES2Test onlines
390 micro
VTAM ENJES2 Prod Onlines
390 micro
z/OS C
WT 100 WT 30
WT 80
Define SFM Couple Data Set
ƒ IXCSFMF member in SYS1.SAMPLIBExecute IXCL1DSU batch utility Alternate SFM couple data set is recommended
Control Statements:
DEFINEDS SYSPLEX(PLXM) DSN(SYS1.SFM#PLXM.CDS01) VOLSER(BMCD01) CATALOG DATA TYPE (SFM) ITEM NAME(POLICY) NUMBER(6) ITEM NAME(SYSTEM) NUMBER(8) ITEM NAME(RECONFIG) NUMBER(4)
Define Sysplex Failure Management Policy
ƒ IXCSFMP member in SYS1.SAMPLIB
Execute IXCMAIPU administrative data utility SFM couple data set must be pre-formatted
IXCMAIPU administrative data utility is used to addupdate, or delete policy data
RACF protect IXCMAIPUResource name ‘MVSADMIN.XCF.SFM' in FACILITY class
DATA TYPE(SFM) REPORT(YES) DEFINE POLICY NAME(NORMAL) CONNFAIL(YES) REPLACE(YES)
SYSTEM NAME(*) WEIGHT(1)
ISOLATETIME(0) SYSTEM NAME(ZMB0) WEIGHT(40) SYSTEM NAME(ZMB1) WEIGHT(40) SYSTEM NAME(ZMB3) WEIGHT(10)
RECONFIG FAILSYS(SYSC) ACTSYS(SYSD) TARGETSYS(ALL) ESTORE(YES) STORE(YES)
SFM Policy Control StatementsExample:
Activating SFM Policy
Make SFM Couple Data Set available to z/OS:
SETXCF COUPLE,PCOUPLE=SYS1.SFM#PLXM.CDS01,TYPE=SFMSETXCF COUPLE,ACOUPLE=SYS1.SFM#PLXM.CDS02,TYPE=SFM
Activate SFM Policy:
SETXCF START,POLICY,POLNAME=NORMAL,TYPE=SFM
Only one member of the sysplex needs to activate the policy
Update COUPLExx member
CDS Types: Sysplex Couple Data Set CFRM SFM Separate/Combined WLMAllocation: Space requirements Primary/AlternateFormat: IXCL1DSU (All)ADMIN: IXCMIAPU (CFRM,SFM) ISPF Interface (WLM)
Sysplex Implementation Summary
SysplexImplementation Activities
IEASYSxx: PLEXCFG GRS GRSCNF GRSCNFxx GRSRNL GRSRNLxx CLOCK CLOCKxx CONSOLE CONSOLxx CNGRPxx COUPLE COUPLExx
CSS ConfigurationOS ConfigurationIOCDSSecurity Profiles CBD.CPC.IOCDS CBD.CPC.IPLPARMIPLPARMHMC Setup Profiles
SYSPLEX NameNetwork Name (S/390 T/R)Processor Id names (HCD)CPC NamesCF NamesStructuresConsolesJES2 CheckpointSignalling Pathsz/OS System NamesHW/SW Requirements
HCD
PARMLIB
Planning
COUPLE
Define checkpoint structure in CFRM
CKPTDEF Parametersƒ CKPTn=(STRNAME=str_name)ƒ MODE=DUPLEX
Recommendationsƒ CKPT1 on CF, CKPT2 on DASDƒ VOLATILE=(ONECKPT=IGNORE,ALLCKPT=DIALOG)ƒ Activate via Dialog
JES2 Checkpoint on CF
z/OS System Logger
APPL2
LOGGER
APPL1
z/OSA
Log Data Set Log Data Set
APPL2
LOGGER
APPL1
z/OSB
List structurelogstream 1
List structurelogstream 2
Coupling Facility
Sysplex-Wide
Offload Process
Offload Process
CICS Tran. Server for z/OSIMS/ESA 6.1 Shared QueuesOperlogLogrecAPPC/MVSz/OS Resource Recovery ServicesWebsphereTVS...
Users of System Logger:LOGWTR A
z/OS_A
IXGLOGR
LOGWTR B
CF_1
LOGWTR A
z/OS_B
LOGWTR B
IXGLOGR
System Logger Users
System Logger Recommendations
Logstream/Structure Recommendations:
Aim for 10-20 logstreams per structure. During recovery, each z/OS will maximize parallelism ACROSS structures, but serially within a single structure. Remember (current) overall limit of 255 structures.
Try to have at least 2 active logstreams per CF structure, connected to more than one system, to allow peer recovery in case of failure.
Try to put logstreams with similar storage requirements in same structure - storage is split evenly between all logstreams, so CF storage will be wasted if logstreams have vastly different usage patterns.
When another logstream is connected, the existing logstreams will be re-sized. This could potentially cause short term logstream-full conditions and impact exploiters.
Logstream/Structure Recommendations:
AVGBUFSIZE & MAXBUFSIZE are specified at structure level, so try to ensure all logstreams in a structure have similar block size characteristics.
Use a realistic number for LOGSNUM - every POTENTIAL logstream takes up some storage in the structure.
Do not oversize the logstream structures - every logstream is potentially duplexed in a data space - so very large logstreams can lead to processor storage constraint. Also, very large logstreams mean long offloads which can impact logger performance. More frequent small offloads are better than a few large ones. One offload every 5-10 minutes would be an ideal balance.
System Logger Recommendations cont...
Offload Dataset Recommendations:
Use a CISZ of 24576 for offload datasets. Staging datasets MUST have a CISZ of 4096 or writes to them will fail.
Make the offload datasets as large as reasonable, to reduce overhead of allocating additional datasets in the middle of an offload. Bear in mind retpd and age of data in each offload dataset.
RETPD and AUTODELETE to control deletion of data from logstream and deletion of log data sets.
Ensure data sets are defined with SHROPTIONS(3,3)
System Logger Recommendations cont...
Recommendations:
For OLTP workloads, use HIGHOFFLOAD of 80% and LOWOFFLOAD of 60% as a starting point. Check the documentation for the connector (CICS or whatever) for specific recommendations, and monitor SMF Type 88 records using IXGRPT1 provided in SAMPLIB.
Do not set HIGHOFFLOAD higher than 80%, in case spurts of activity would fill the log stream before OFFLOAD can provide additional space.
Do not set HIGHOFFLOAD so high that you rarely get offloads - log stream and offload data sets only get cleaned up when offload is invoked.
Make sure you have sufficient auxiliary storage to back the logger data spaces.
IXGRPT1 provides counts of number of offloads, number of structure full and entry full, and avg buffer size, amongst other things. See SMF manual, macro IXGSMF88 in SYS1.MACLIB, and member IXGRPT1 in SYS1.SAMPLIB for a description of all the fields.
System Logger Recommendations cont...
Offload devices should be fast enough to offload difference between HIGHOFFLOAD and LOWOFFLOAD faster than space above HIGHOFFLOAD fills up.
System Logger Review
Format Logger Inventory
Format the z/OS Logger Inventory Couple Data Set with:LSR – number of structuresLSTRR – number of log streams
//STEP1 EXEC PGM=IXCL1DSU//SYSPRINT DD *//SYSIN DD *DEFINEDS SYSPLEX(PLXM)DSN(SYS1.LGR#PLXM.CDS01) VOLSER(BMCD03)CATALOG
DATA TYPE(LOGR)ITEM NAME(LSR) NUMBER(5)ITEM NAME(LSTRR) NUMBER(10)
Define Log Streams
Associate data sets, log stream names, structure names and attributes.–Structures may be defined or deleted –Streams may be defined, deleted or updated
//STEP1 EXEC PGM=IXCMIAPU//SYSIN DD *DATA TYPE(LOGR) REPORT(YES)DEFINE STRUCTURE NAME(LOGGER_OPERLOG)AVGBUFSIZE(512)MAXBUFSIZE(4096) LOGSNUM(5)
DEFINE LOGSTREAM NAME(SYSPLEX_OPERLOG)STRUCTNAME(LOGGER_OPERLOG)...
Update the CFRM Policy
Update CFRM policy with names of the structures to be used by z/OS System Logger.
//STEP1 EXEC PGM=IXCMIAPU//SYSIN DD *DATA TYPE(CFRM) REPORT(YES)
. . .DEFINE STR(LOGGER_OPERLOG) SIZE(13568) PREFLIST(C033,C021)
Automatic Restart Manager
The Automatic Restart Manager (ARM) is an z/OS recovery function– Improves the availability of specified subsystems and applications–Automatically restarting them as requested–Function of the Cross-System Coupling Facility (XCF) component ƒ Runs in XCF address space ƒ Uses data spaces
–Augments the functions of production controllers, automation products, and job schedulers–Subsystems that use ARM are expected to perform their own transaction level and database recovery–Requires:ƒ ARM Couple data sets which have connectivity to all the systems on which
ARM is active
ARM Environment
XCF XCF
ARM
ARM
ARM
Couple Data Set
StartedTasks/
Batch
StartedTasks/
Batch
CouplingFacility
SYSA SYSB
z/OS z/OS
ARM Restart Inplace
CF
SYSA SYSB
RTM
Error
Application
AutomaticRestart Manager
EOM
Resource Manager
- Invoke Exits
- Determine ifElement isrestartable
- ExecuteappropriateRestartMetho
d
Restarton SYSA
Executingon SYSA
ARM Restart on other Systems
ARM
SYSA
SYSB SYSC
GRP01
Appl1Appl2Appl3
GRP02
Appl4Appl5 ARM
Policy
Couple Data SetCF
GRP01
Appl1Appl2Appl3
GRP02
Appl4Appl5
SYSB leaves Sysplex
XCF Address Space
Applicationsdiscontinueon SYSB
Restart on SYSA
Restart on SYSC
XCF Statusupdate missing
ARM Couple Data Sets
PrimaryARM
Couple Data Set
AlternateARM
Couple Data Set
Couple Data Set Format Utility
.
.
DEFINEDS SYSPLEX(PLXM) DSN(SYS1.ARM#PLXM.CDS01) VOLSER(BMCD01) DATA TYPE(ARM) ITEM NAME(POLICY) NUMBER(3) ITEM NAME(MAXELEM) NUMBER(10) ITEM NAME(TOTELEM) NUMBER(500)
ARM Policy - IXCMIAPU
//IXCARMP0 JOB//STEP1 EXEC PGM=IXCMIAPU//SYSPRINT DD SYSOUT=A//SYSIN DD * DATA TYPE(ARM) DEFINE POLICY NAME(ARMPLXM1) RESTART_GROUP(DEFAULT) TARGET_SYSTEM(*) ELEMENT(*) RESTART_ATTEMPTS(0) RESTART_GROUP(VTAMGRP) TARGER_SYSTEM(*) ELEMENT(NET@V*) RESTART_ATTEMPTS(3,300) READY_TIMEOUT(900) TERMTYPE(ELEMTERM)/*
IXCMIAPU Utility example