The document provides a comprehensive overview of IBM's z/OS communications server, focusing on sysplex configurations, dynamic virtual IP address (DVIPA) management, and application-specific networking. Key concepts discussed include interface resilience, dynamic connectivity, single system images, and distribution methods for workload balancing within a sysplex environment, employing techniques such as weighted active routing and timed affinity. The text also outlines the interaction of various TCP/IP stacks and the use of coupling facilities for efficient resource management in enterprise networking solutions.

1. ®
IBM Software Group –Enterprise Networking Solutions
z/OS®Communications Server
z/OS Communications Server Development, Raleigh, North Carolina
Sysplex In a Nutshell
Andrew Arrowood -arrowood@us.ibm.com

2. IBM Software Group –Enterprise Networking Solutions
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Interface 21:
IP Addr 2234::2
Interface 22:
IP Addr 2235::2
Background –Virtual IP Address
Application access independent of network topology
–VIPA identifies the server application, not the physical interface
–Physical interface IP addresses can change without affecting end-user
–No changes needed in DNS or hosts file configuration
Interface resilience
–Communication with a server host is unaffected as long as a physical interface is active
–Example: As long as interface 21 or 22 is active, the connection to the CICS application stays active
TCPIP1
CICS
201.81.1.0
PORT 5000
Advertise: VIPA 201.81.1.0

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DYNAMICXCF Interfaces
TCP/IP
Stack-1
TCP/IP
Stack-2
LPAR-1
TCP/IP
Stack-3
LPAR-2
zSeries CPC-1
HiperSockets
IUTSAMEH
TCP/IP
Stack-4
LPAR-3
CPC-2
XCF Signaling
Dynamic connectivity is automatically established between all sysplexmembers
Using XCF messaging, each stack automatically learns of other sysplexmembers
Under-the-covers DYNAMICXCF interfaces are created using one of three transport technologies depending on availability and location of partner stack
–Inside same LPAR: IUTSAMEH(memory-link inside a z/OS system)
–Inside same CPC: HiperSockets(if enabled for that purpose via IQDCHPID VTAM start option)
–Between CPCs –XCF Signaling

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Coupling
Facility
Sysplex Dynamic VIPAs, Stack managed DVIPAs
LPAR1
CICS
TCPIP1
Advertise:
201.81.10.7
VIPADEFINE
255.255.255.0 201.81.10.7
Single System Image:
–Location of application transparent to clients
–DVIPA identifies the TCP application independently of which stack in the Sysplex the server is currently active on
LPAR2
CICS
TCPIP2
VIPABACKUP
200201.81.10.7
LPAR3
CICS
TCPIP3
VIPABACKUP
100201.81.10.7
DVIPA activation is managed by the stacks:
–VIPADEFINE statement -defines the primary owner of the DVIPA
–VIPABACKUP statement – defines the backup owner(s) of the DVIPA
•Highest Rank determines which stack takes over
–TCPIP2 Rank 200
–TCPIP3 rank 100
Coupling Facility
–XCF messaging between sysplex members
–Automatic notification of member changes

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Coupling
Facility
Sysplex Dynamic VIPAs, Stack managed DVIPAs
LPAR1
CICS
TCPIP1
VIPADEFINE
255.255.255.0 201.81.10.7
LPAR2
CICS
TCPIP2
VIPABACKUP
200 201.81.10.7
LPAR3
CICS
TCPIP3
VIPABACKUP
100 201.81.10.7
Unplanned takeover
If TCPIP1 fails,
–DVIPA moves to TCPIP2 since it is highest ranked backup,
–TCPIP2 advertises the DVIPA
–TCPIP2 CICS application takes over workload
–TCPIP2 sends connection resets to client on behalf of stack 1 which reduces workload restart time
Advertise:
201.81.10.7

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Coupling
Facility
Sysplex Dynamic VIPAs, Stack managed DVIPAs
LPAR1
CICS
TCPIP1
VIPADEFINE
255.255.255.0 201.81.10.7
LPAR2
CICS
TCPIP2
VIPABACKUP
200 201.81.10.7
LPAR3
CICS
TCPIP3
VIPABACKUP
100 201.81.10.7
Planned takeover
TCPIP1 is restarted
–DVIPA moves back to TCPIP1
–TCPIP1 advertises the DVIPA
–TCPIP1 handles routing for workload still going to TCPIP2 CICS
–TCPIP1 CICS application takes over new workload
Advertise:
201.81.10.7
V TCPIP,TCPIP1,SYSPLEX,DEACT,DVIPA=201.81.10.7
V TCPIP,TCPIP1,SYSPLEX,REACT,DVIPA=201.81.10.7
Operator commands allow planned takeover without changing configuration:

7. IBM Software Group –Enterprise Networking Solutions
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Application-specific DVIPAs
Single-instance applications require that one instance is active in the Sysplex:
–Application may need exclusive access to certain resources
The Application controls the activation and movement of the DVIPA:
–In the example, CICS1 initially causes the DVIPA to be created on stack 3 (Bind or MODDVIPA IOCTL)
–The application fails, and restarts on another LPAR (stack 4), causing the DVIPA to move from stack 3 to stack 4 (existing connections will be reset)
–Speed of recovery –controlled by ARM (Automated Restart Manager) or automated operations
TCPIP3
CICS1
10.1.1.1
Advertise:
DVIPA 10.1.1.1
TCPIP4
CICS1
10.1.1.1
Advertise:
DVIPA 10.1.1.1
CICS1 fails.
Restarts on Stack4
DNS
Resolve:
cics1.mycom.com
Either:
1.Resolve cics1.mycom.com
2.Connect to returned address
Or
1.Connect to cached (or hardcoded)
address
10.1.1.1 is an application- specific DVIPA
VIPARANGE statement defines a subnet range
VIPARANGE 255.255.0.0 10.1.0.0
10.1.1.1

8. IBM Software Group –Enterprise Networking Solutions
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Advertise:
201.81.10.7
VIPADEFINE
255.255.255.0 201.81.10.7
VIPADISTRIBUTE
DISTMETHOD SERVERWLM
201.81.10.7 PORT 5000
DESTIP ALL
SysplexDynamic VIPAs, Distributed DVIPAs
LPAR1
CICS
5000
TCPIP1
LPAR2
TCPIP2
LPAR3
TCPIP3
LPAR2
TCPIP2
VIPABACKUP
200 201.81.10.7
Single System Image:
–Multipleapplications look like a single application to clients
–DVIPA identifies the TCP application independently of which stacks the application is currently active on
SysplexDistributor:
–Balances Workload within Sysplexby using a distributed DVIPA, advertised by the distributing stack
Datapath-either
–XCF interfaces or VIPAROUTE
VIPAROUTE
–IP route from distributor to target
–Allows OSA instead of XCF
–Doesn’t use CF resources
Sysplex
Distributor
CICS
5000
CICS
5000
VIPADISTRIBUTE statement
–specify DVIPA (and PORT(s)) of listening applications
•Dynamic Ports –Learn port as application starts a Listener
–DISTMETHOD -distribution method
–DESTIP –XCF IP address of each target stack or ALLstacks

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Sysplex Distribution methods
The sysplex distributor uses one of five distribution methods when routing incoming connections to TCP/IP stacks:
–Static Distribution:
•RoundRobin –Evenly distribute connections to all targets
•WeightedActive –Balance active connections to all targets based on configured weight proportions
–Distribution using dynamic WLM recommendation:
Weighted round-robin distribution based on a normalized WLM weight:
•BaseWLM –WLM system weights
–Comparison of displaceable CP capacity of lower importance work
•ServerWLM –WLM server-specific weights
–Comparison of displaceable CP capacity given importance level of workload
–How well is application meeting their WLM service class goals
–HotStandby –one active target, multiple backups
10 Connection Requests
3 Connections
2 Connections
XCF1
XCF2
Distributor
XCF3
5 Connections
XCF2
XCF3
XCF1
Normalized
Weight
2
5
3
Ready 1
Ready 1
Ready 1
Distribution using WLM recommendations:

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Sysplex Distribution using WLM –additional monitoring
TSR: Target Server Responsiveness fraction, which is a compound health-metric per target server (range from 0 (bad) to 100 (good)):
–TCSR: Target Connectivity Success Rate. Connectivity between the distributing stack and the target stack -are the new connection requests reaching the target? (0 is bad, 100 is good)
–SEF: Server accept Efficiency Fraction. Target Server accept efficiency -is the server accepting new work? (0 is bad, 100 is good)
–QoS: QoS fractions. Consider retransmits and packet loss. (0 is good, 100 is bad)
–Number of half-open connections also impact the TSR value
CER: Connection Establishment Rate. Network connectivity between Server and client -are new connections being established? (0 is bad, 100 is good)
–Does not impact the TSR value, but is included in netstat displays

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Sysplex Distribution - Weighted Active
10 Connection Requests
3 Connections
2 Connections
XCF1
XCF2
Distributor
5 Connections XCF3
Initial Distribution
Active Conns
XCF2 20 0 2
XCF3 50 0 5
XCF1 30 0 3
VIPADEFINE DVIPA1
VIPADISTRIBUTE DISTMETHOD WEIGHTEDACTIVE
DVIPA1 PORT 6000
DESTIP XCF1 WEIGHT 30
XCF2 WEIGHT 20
XCF3 WEIGHT 50
Active connections balanced across ready
targets
10 Connection Requests
10 Connections
XCF1
XCF2
Distributor
XCF3
Over Time
Active Conns
XCF2 20 190 200
XCF3 50 530 530
XCF1 30 300 300
Ready
Ready
Ready
Ready
Ready
Ready

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Sysplex Distributor - Hot Standby support
 A single target server receives all new connection requests
– Other target servers are active but not receiving new
connection requests
– Automatically route traffic to “hot-standby” target server when
the active target server is not available
 Enable using a new HOTSTANDBY distribution method
– One preferred target
– And one or more backup targets ranked in order of
preference
– A target is not available when:
• Not ready
• Route to target is inactive
• If HEALTHSWITCH option configured – target is not
healthy when
– TSR = 0% OR
– Abnormal terminations = 1000 OR
– Server reported Health = 0%
– AUTOSWITCHBACK option - switch to the preferred target if
it becomes available
• No auto switch back if reason for original switch was
health problems
– Use a V TCPIP Quiesce and Resume sequence
Sysplex
Distributor
Preferred
Target
server
Backup
Target
server
DB2 DB2
DB2 Data
sharing group
VIPADEFINE DVIPA1
VIPADISTRIBUTE DISTMETHOD HOTSTANDBY
AUTOSWITCHBACK HEALTHSWITCH
DVIPA1 PORT nnnn
DESTIP XCF1 PREFERRED
DESTIP XCF2 BACKUP 50
DESTIP XCF3 BACKUP 100

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Sysplex Distribution –ServerWLM Importance level weighting
Server-specific weights
Comparison of displaceable capacity given the importance level of the service class.
Importance
level
0
1
2
3
5
4
6
7
LPAR2
0 Service units
0 Service units
0 Service units
0 Service units
500Service units
LPAR1
0 Service units
0 Service units
0 Service units
0 Service units
500Service units
New JAVA work
Importance level 2
Displaces
Level 3-7 Workloads
Example:
WLM weights –same for LPAR1 and LPAR2
–Same displaceable level 3 –7 SUs, 500 SUs
But LPAR2 (500 SUs IL 5) should be favored over LPAR 1 (500 SUs IL 3)
ILWEIGHTING parameter -favor LPARs with lower importance level displaceable SUs
–IL 0 Ignore –no change from existing logic.
–IL 1 Moderate
–IL 2 Aggressive
–IL 3 Exceptionally Aggressive
VIPADISTRIBUTE
DISTMETHOD SERVERWLM
ILWEIGHTING 1

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WLM weights and specialty processors
Distribution also considers specialty processors:
Specialty processors are deployed and exploited by targeted workloads on z/OS:
zAAP (zSeries Application Assist Processor) –JAVA workloads such as WAS
zIIP (System z Integrated Information Processor)
–DB2 related workloads
–z/OS IPSEC workloads

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Sysplex Distribution –ServerWLM Crossover Cost
Server-specific weights
Comparison of displaceable capacity based on actual usage percentage of each processor by the workload
Example:
JAVA workload designed to use 10% CP 90% zAAP SUs
Each LPAR has same displaceable capacity -1000 SUs
But as 1000 SUs are consumed -ideally 100 CP and 900 zAAP SUs consumed
PROCXCOST parm penalizes zAAP intended SUs that crossover and run on the CP
Higher PROXCOST value, the more WLM favors LPAR2
PROCXCOST ZAAP 1 ZIIP 1 –no penalty LPAR1 = LPAR2
VIPADISTRIBUTE
DISTMETHOD SERVERWLM
PROCXCOST ZAAP 5 ZIIP 5
Displaces
Level 3-7 Workloads
New JAVA work
Importance level 2
Designed Usage
CP 10% zAAP 90%
Actual LPAR1 Usage
CP 90% zAAP 10%
VS
LPAR2
CP SUs
zAAP SUs
0
1
2
3
5
4
6
7
100 SUs
900 SUs
0 SUs
0 SUs
0 SUs
0 SUs
0 SUs
0 SUs
0 SUs
0 SUs
Importance
level
CP SUs
zAAP SUs
900 SUs
100 SUs
0 SUs
0 SUs
0 SUs
0 SUs
0 SUs
0 SUs
LPAR1
0 SUs
0 SUs

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Sysplex Distribution -Timed Affinity
LPAR1
LPAR2
LPAR4
LPAR3
CICS1
CICS2
CICS4
CICS3
TCPIP2
TCPIP3
TCPIP3
TCPIP1
External Network
TIMEDAFFINITY
–Choose target for new client using distribution method
–Same target for new connections from same client IP@
–Keep affinity until TIMEDAFFINITY seconds after last connection ends
VIPADISTRIBUTE TIMEDAFFINITY 5
–Keep affinity until 5 seconds after last connection ends.
Used with
–Base and Server WLM distribution
–Weighted Active
–Round Robin
201.81.10.1
Tier 1 SD
199.81.10.2

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Sysplex Distribution –OPTLOCAL, Optimized local routing
LPAR1
LPAR2
LPAR4
LPAR3
CICS1
CICS2
Tier 1 SD
CICS4
CICS3
Tier 2 Connection setup and Data path stay local when possible
Tier 2 SD
WAS1
WAS2
WAS4
WAS3
Client Connections
VIPADISTRIBUTE OPTLOCAL
•Prefer local server
•Control level of preference
Sysplex Distributor can optimize session setup and datapath when connection endpoints are on the same TCP/IP stack
•OPTLOCAL 0: Use local server
if there are no server problems:
not ready, backlog growing, abnormal transactions, server health
•OPTLOCAL 1: Use local server
if there are no server problems& WLM raw weight is not zero.
•OPTLOCAL 2-16: Use local server
if there are no server problems& WLM raw weight is not zero&
normalized weight * value > normalized weight of non-local servers
TCPIP2
TCPIP3
TCPIP3
TCPIP1
Use SD if OPTLOCAL conditions not met
External Network

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Sysplex Distribution -Tier 1 load balancing using Tier2 application awareness
LPAR1
LPAR2
LPAR4
LPAR3
CICS1
CICS2
Tier 1 SD
CICS4
CICS3
WAS1
WAS2
WAS4
WAS3
TCPIP2
TCPIP3
TCPIP4
TCPIP1
WLM 10
WLM 10
WLM 10
WLM 10
•Tier 1 distribution decision -based on both application tiers
•Application tiers linked by group name
•The Tier 1 distributor chooses target using combined weight of Tier1 and Tier2 Group1servers on each LPAR
Tier 1GROUP1
Tier 2 GROUP1
T1T2 5
T1T2 10
T1T2 10
T1T2 10
Tier 2 SD
WLM 1
WLM 10
WLM 10
WLM 10
VIPADEFINE TIER1
255.255.255.0 DVIPA1
VIPADISTRIBUTE TIER1 GROUP1
DISTMETHOD SERVERWLM
DVIPA1 Port 10000
DESTIP ALL
1
VIPADEFINE TIER2
255.255.255.0 DVIPA2
VIPADISTRIBUTE TIER2 GROUP1
OPTLOCAL 1
DISTMETHOD SERVERWLM
DVIPA2 Port 10002
DESTIP ALL
2
2
1

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Sysplex Distribution -Tier 1/Tier 2 CPC optimizations
CPC2
LPAR1
LPAR4
LPAR3
Tier 1 SD
Tier 2 SD CPCSCOPE
WAS4
WAS3
TCPIP3
TCPIP4
TCPIP1
WLM 0
WLM 10
WLM 10
WLM 10
WLM 10
T1T2 5
T1T2 10
T1T2 10
CPC1
WAS1
CICS1
CICS4
CICS3
Tier 2 GROUP1
LPAR2
TCPIP2
T1T2 10
CICS2
Tier 2 SD CPCSCOPE
WLM 10
WLM 10
Tier 1 GROUP1
T2 GROUP1 Wts
Client Connections
WAS2
WLM 10
Tier 2 GROUP1
VIPADEFINE TIER1
255.255.255.0 DVIPA1
VIPADISTRIBUTE TIER1 GROUP1
DISTMETHOD SERVERWLM
DVIPA1 Port 10000
DESTIP XCF1 XCF2 XCF3 XCF4
1
VIPADEFINE TIER2 CPCSCOPE
255.255.255.0 DVIPA3
VIPADISTRIBUTE TIER2 GROUP1
OPTLOCAL 1
DISTMETHOD SERVERWLM
DVIPA3 Port 10002
DESTIP ALL
2
CPCSCOPE –keep connections with Tier 2 SD’s CPC
VIPABACKUP DVIPA –within CPC
When Tier 1 SD chooses WAS1
–Tier 2 SD will choose CICS2 since CICS1 weight is 0
–Tier 2 connection path stays within CPC
•Better performance
•Potential to relax security requirements
2
1

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Sysplex Distributor support for DataPower
CPC1
LPAR1 LPAR2 LPAR3 LPAR4
CICS CICS CICS CICS
WAS WAS WAS WAS
TCPIP1 TCPIP2 TCPIP3 TCPIP3
IMS IMS IMS IMS
DB2 DB2 DB2 DB2
Tier1:
CPC2
Sysplex Distributor Sysplex Distributor
Web
Service
request
Sysplex Distributor
•DataPower weights for Load Balancing
•Connection state information allows
non-disruptive takeover, return path to
bypass SD
Tier1 SD TCP control connection
to each DataPower
 Distributor sends DVIPA/Ports
& polling interval
 DataPower
– Configures non-advertised
DVIPAs
Sends:
– Server availability
– Connection states
• Allows non-disruptive takeover
by backup SD
• Termination – allows GRE
routing (bypass SD on return
path)
– Weight (capacity)
• SD load balances using
DataPower weights

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Sysplex Distributor support for DataPower, Target Controlled distribution
LPAR1
LPAR2
LPAR4
LPAR3
Tier 1 SD
WAS1
WAS2
WAS4
WAS3
TCPIP2
TCPIP3
TCPIP4
TCPIP1
Tier 1 GROUP1
Tier 2 SD
WLM 10
WLM 10
WLM 10
WLM 10
201.81.10.1
1
VIPADEFINE TIER1
255.255.255.0 DVIPA1
VIPADISTRIBUTE TIER1 GROUP1
GRE CONTROLPORT 1702
DISTMETHOD TARGCONTROLLED
DVIPA1 Port 10000
DESTIP 201.81.10.1 201.81.10.2
201.81.20.3 201.81.20.4
Web
Service
request
1
201.81.10.2
DATAP1
DATAP2
DATAP3
DATAP4
201.81.20.3
201.81.20.4
Tier 1 SD supports DataPower:
TARGCONTROLLED distribution
GRE
–Target is non-z/OS target (DataPower)
–Routing type is GRE
CONTROLPORT
–destination port for TCP control connection

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Solution: Sysplex Distributor Multi-Site support for DataPower
CPC1
CPC2
LPAR1
LPAR2
LPAR4
LPAR3
Tier 1 SD
WAS1
WAS2
WAS4
WAS3
TCPIP2
TCPIP3
TCPIP4
TCPIP1
•Each DataPower -configured to connect to a group of servers on a site (CPC).
•Tier 1 distribution –load balance using DataPower weight and site weight of matching Tier 2 server group (GROUP1)
•DATAP4 is preferred over DATAP3 based on reported datapower weights.
•DATAP3 & DATAP4 are preferred over DATAP1 and DATAP2 based on TIER 2 server weights.
Tier 1GROUP1
Tier 2 GROUP1
WLM 2
WLM 10
WLM 10
WLM 10
Web
Service
request
DATAP1
DP Wt 500
Tier 2 SD CPCSCOPE
Tier 2 SD CPCSCOPE
DATAP2
DP Wt 500
DATAP3
DP Wt 500
DATAP4
DP Wt 900
NmWt 3
NmWt 3
NmWt 5
NmWt 9

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SYSPLEXPORTS -Outbound Connections from Distributed DVIPAs
SYSPLEXPORTS:
–Ensure unique ephemeral source ports for each DVIPA in sysplex
–Coupling Facility -manages source DVIPA ports.
–Allocated from CF inblocks of 64 ports
–Used as server applications establish connections to clients
Client IP address 8.1.1.1 Port 3001
TCPIP2 connections from from DVIPA 10.1.1.1 uses source ports from 5001-5064 port range
TCPIP3 connections from DVIPA 10.1.1.1 uses source ports from 5068, 5070-5129 range
TCPIP1
TCPIP2
TCPIP3
Sysplex
Distributor
CICS
10.1.1.1
CICS
10.1.1.1
Advertise:
DVIPA 10.1.1.1
DVIPA 10.1.1.1
…
5001-5064
5068,5070-5129

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SWSA –Sysplex Wide Security Associations
2. Shadow tunnel created from target back to client
1. Distributor handles SA negotiation
Sysplex Distributor support for IP Sec workloads target systems
Distributor handles SA negotiation and refresh
Requires Coupling Facility DVIPA Takeover
–Keeps Tunnel renegotiation information
–Tunnel sequence number for shared tunnel
–SYSPLEXPORTS -ensure unique source ports for outbound connections from distributed applications back to the same client
TCPIP2
CICS
10.1.1.1
TCPIP3
CICS
10.1.1.1
TCPIP1
Sysplex
Distributor
Advertise:
DVIPA 10.1.1.1

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XCF Monitor:
Is each Stack’s sysplex component responsive?
Sysplex Autonomics
Stack Monitor:
OMPROUTE up?
VTAM up?
XCF links up?
Am I ok?
Connectivity to router?
Stack Monitor:
OMPROUTE up?
VTAM up?
XCF links up?
Am I ok?
Connectivity to router?
Stack Monitor:
OMPROUTE up?
VTAM up?
XCF links up?
Am I ok?
Connectivity to router?
Sysplex Problem Detection and Recovery
GLOBALCONFIG SYSPLEXMONITOR
TIMERSECS 60
(NO)DELAYJOIN
(NO)MONINTERFACE (NO)DYNROUTE
(NO)RECOVERY (NO)AUTOREJOIN
Detect problems that affect TCP/IP Sysplex Health:
–Time dependent monitoring:
•Is OMPROUTEactive?
•Is VTAM active?
•Is storage (common or private) critical?
•Are important interfaces (and routes over those interfaces) active?
•XCF detection –Are sysplex functions responsive?
–Non-time dependent monitoring –Sysplex abend
Recovery from problems:
–Leave sysplex group (RECOVERY)
–Issue actionable message
–Monitoring continues for recoverable problems
•OMPROUTE, VTAM, Storage, Interface (and route)
•When problem clears, clear message, rejoin sysplex group (AUTOREJOIN)

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Subplexing
Subplexing allows isolation of multiple secure areas.
•Without subplexing:
SD requires DYNAMICXCF
–Establishes IP Connectivity to all stacks in Sysplex
–Dynamic IP@ discovery across sysplex
Coupling Facility resources span the sysplex
–VTAM generic resource, Multi-Node Persistent Sessions resources
–Sysplex ports resources, SWSA resources
LPAR2
LPAR1
LPAR3
LPAR4
LPAR5
VTAM1
Internet SNA
TCPIP1
Intranet Production IP
Intranet Dev. IP
TCPIP2
TCPIP3
TCPIP4
TCPIP5
TCPIP8
VTAM3
VTAM4
VTAM5
VTAM2
TCPIP6
TCPIP7
Internet IP
Intranet SNA

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LPAR2
Internet SNA subplex
VTAM XCFGRPID:Default (01)
LPAR1
LPAR3
LPAR4
LPAR5
VTAM2
VTAM1
Internet IP subplex
TCP/IP XCFGRPID:Default (01)
TCPIP2
TCPIP1
Intranet SNA subplex
VTAM XCFGRPID: 21
VTAM3
VTAM4
VTAM5
Intranet Production IP subplex
TCP/IP XCFGRPID: 02
TCPIP3
TCPIP4
TCPIP5
TCPIP8
Intranet Dev. IP subplex
TCP/IP XCFGRPID: 04
TCPIP7
TCPIP6
Sysplex Group: EZBTCPCS
Sysplex Group: EZBT2102
Sysplex Group: EZBT2104
Subplexing
DYNAMICXCF
–Establishes IP Connectivity to all stacks in Subplex
–Dynamic IP@ discovery across subplex
Coupling Facility resources span the subplex
–VTAM generic resource, Multi-Node Persistent Sessions resources
–Sysplex ports resources, SWSA resources