MSC Overview04/21/2016

IMS MSC Team: Mark Ziebarth (C) Suling Li (D)

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Agenda:1. What is MSC?

2. How do customers use MSC?

3. Type of MSC links

4. MSC Definition

5. How to enable Dynamic MSC?

6. Where to save and get MSC resources?

7. Example of MSC communications

8. Q & A

What is MSC?

MSC stands for Multiple Systems Coupling- A way to communicate between IMS systems

Connects multiple IMS systems together in the • Same location or• Different locations

Distributes workloads from one IMS system to another Routes and controls message traffic between connected IMS systems Communication can occur between two or more (up to 2036) IMS

systems running on any supported combination of operating systems

5

End user

Transaction

End user

TERMINAL

IMS MSC Systems

IMS 1

IMS 3

IMS 2036IMS 5

What is MSC cont.

MSC

MSCMSC

MSC

MSCMSC

IMS 2

IMS 4

Application

Program

How Customers use MSC? - Customer’s MSC Configuration 1

JAPEN BRIDGE (US) US

MSC LINKS MSC LINKS

IMS1 runs on

IMS V10

IMS2

IMS V12

IMS3 runs on

IMS V14

MSC MSCMSCVTAM TCP/IP

LPAR1 LPAR2

IMS1A

IMS1B

IMS2

IMS PLEX1

MSC

LINK

S

How Customers use MSC?- Customer’s MSC Configuration 2

IMS PLEX2

MSC

MSC

MSC

MSC LINKS

MSC LINKS

LPAR1 LPAR2

MSC LINKSIMS1A

IMS1B

IMS2A

IMS2B

IMSPLEX1 IMSPLEX2

- Customer’s MSC Configuration 3

How Customers use MSC?

MSC LINKS

MSC LINKS MSC LINKSMSC

MSC

MSC

MSC

How Customers use MSC? - MSC Configuration 4

Type of MSC LinksClassified by the physical connection methods

CTC - Channel to Channel adapter • Same data center• Hardware connection• One logical link

MTM - Memory to Memory• Same Logical Partition• Software• One logical link

TCP/IP• Different data center• IMS connect manages the TCP/IP connections and protocols• The Structured Call Interface (SCI) manages communication between MSC and connect• Multiple logical links• Bandwidth mode

VTAM• Different data center• Multiple logical links

Type of MSC LINKS Cont.

11

IMS1

LPAR1 z/OS

CTC ADAPTER

IMS4IMS3IMS2

VTAMTCP/IP

LPAR2 z/OS

PLINKT

PLINKT

PLINKV

PLINKMPLINKMPLINKCPLINKC

LPAR3 z/OS

MTM

MSC

MSCMSC

PLINKV PLINKT

MSC

PLINKV

TCP/IP

VTAM

Data Center 1

Data Center 2

MSC Definition

Static MSC definition (SYSGEN) Dynamic MSC definition

MSC resources)

Physical link Logical link Msname (Logical link path) Name (remote LTERM)

MSC Definition cont.

MSC Definition - Static

During system definition time, use MSPLINK macro to define an MSC physical link MSLINK macro to define an MSC logical link MSNAME macro to define an MSC logical link path NAME macro to define a remote LTERM (A remote

LTERM is a logical terminal that does not reside on the local system)

Stage 1 GEN

PLNK12TA MSPLINK TYPE=TCPIP,NAME=IMS2,LCLICON=HWS1,LCLPLKID=MSC12, X

SESSION=2,BUFSIZE=65536

LNK12T01 MSLINK PARTNER=TA,MSPLINK=PLNK12TA,OPTIONS=SYNCSESS

LINK12T1 MSNAME SYSID=(21,11)

NAME HOG0B

System identifiers (SYSIDs) SYSID is a two byte number (1 - 2036 )

Local SYSID is local to the owning IMS

Remote SYSID is not the owning IMS. To any other IMS in the MSC Network.

Paths to other IMS systems are determined by the remote SYSID value

Define a path between IMS2 and IMS1

LPATH21 MSNAME SYSID=(11,21)

Define a path between IMS1 and IMS2

LPATH12 MSNAME SYSID=(21,11)

IMS1 Local sysid 10

Local sysid 11

Local sysid 12

IMS2 Local sysid 20

Local sysid 21

Local sysid 22

LPATH12

LPATH21

MSC Definition – Dynamic

From V10, customers can use IMS UPDATE (UPD) commands to dynamically modify MSC definitions for

Physical links Logical links MSNAME (Logical link path)

MSC Definition – Dynamic cont.

From IMS V14, user can use IMS CREATE (CRE) and DELETE (DEL) commands to dynamically create and delete MSC resource

Physical links Logical links MSNAMEs (Logical link paths) Remote logical terminals (NAME - LTERM)

Without bringing system down

MSC Definition – Dynamic cont.

CRE MSPLINK NAME(PLINKM) SET(TYPE(MTM)) CRE MSLINK NAME(LINK) PARTER(AB) CRE MSNAME NAME(LPATH) CRE LTERM NAME(RMTLT) SET(MSNAME(PNAME))

DEL MSPLINK NAME(*) DEL MSLINK NAME(*) DEL MSNAME NAME(*) DEL LTERM NAME(*)

UPD MSPLINK NAME(PLINKM) SET(BUFSIZE(4096)) UPD MSLINK NAME(LINK) SET(MSPLINK(PLINKM)) UPD MSNAME NAME(LINK12T1) SET(MSLINK(NEWLINK))

Create MSC resources

Create cmd can add MSPLINK MSLINK MSNAME LTERM (remote LTERM)

into your system while system is running

Delete MSC resources

DELETE cmd can delete MSPLINK MSLINK MSNAME LTERM (remote LTERM)

If the resources are still used, the delete commands will failUse QRY command to find out the status if it is needed

How to enable Dynamic MSC?

With MSC GENed environment– Add <SECTION=MSC> in DFSDFxxx PROC member– Coding MSCRSCS=DYN|NODYN

Without MSC GENed environment – Specifying MSC=Y|N execute parameter– Add <SECTION=MSC> in DFSDFxxx PROC member– Coding MSCRSCS=DYN|NODYN

Example of DFSDFxxx member

Example of DFSDFxxx member if no GENed MSC

Where to save/get MSC resources?

Include Repository Section in DFSDFxxx <SECTION=REPOSITORY> REPOSITORY=(TYPE=IMSRSC)

Coding AUTOEXPORT parm as below <SECTION=DYNAMIC_RESOURCES> AUTOEXPORT=AUTOAUTOIMPORT=AUTO

Example of DFSDFxxx for EXPORT/IMPORT

DemoBring up IMS with Dynamic MSC enabledCreate MSPLINK, MSLINK, MSNAMEStart links, Sending message from local IMS to remote IMS via MSC

BASIC MESSAGE FLOW cont.

28

INPUT MESSAGE FLOW

IMSA IMSB IMSC

MSGQMSGQ MSGQ

(5)(3)

T1

(1) (2) (4) (6)

MSC MSC MSCCTC VTAM

Input System (Origin)

Processing System (Destination)

Intermediate System

Basic message flow in the MSC Network1. Terminal TI enters a transaction in IMSA which is to be processed in IMSC.2. The message is placed in the message queue.3. The message is taken off the message queue and sent across the CTC link

to IMSB.4. IMSB will put the message on its message queue, take it off and,5. send the messages across the VTAM link to IMSC.6. IMSC puts the message on its message queue and determines it is to be

processed local.7. The application program is scheduled and processes in IMSC. It inserts a

response message back to the input terminal.8. The response message is put in the message queue, then 9. sent back across the VTAM link to IMSB.10. The message arrives in IMSB and is put on the message queue.11. The message is sent across the CTC link to IMSA.12. In IMSA the response message is placed in the message queue, then taken

off, and is sent to Terminal T1.

29

BASIC MESSAGE FLOW cont.

30

OUTPUT MESSAGE FLOW

IMSA IMSB IMSC

MSGQMSGQ MSGQ

(9)(11)

T1(12) (10) (8)

MSC MSC MSC

Input System (Origin)

Processing System (Destination)

CTC VTAM

(7)

Intermediate System

Dependent Region

Application PGM

Application PGM

Sending Message Over TCP/IP Link

31

IMS3

MSC

Processing System (Destination)

MSCIMS2

IMS1

CQS1

CQS2

IMSPlex1

PMTO

MSC

TCPIP

CF

Lterm

Application PGM

Operator

This is the terminal (Lterm) that connects to IMS1, it wants to send a message to IMS3 then the msg will be processed in IMS3 by an application pgm (DFSDDLT0)

TRAN21T0 Hi EVERYBODY, CUSTOMERS’ INTERNS ARRIVED IN SVL.

This is the application program (DFSDDLT0)

This is the master terminal (PMTO) that connects to IMS3

I GOT NEWS CUSTOMERS’ INTERNS ARE HERE NOW

The logical terminal (Lterm) is informed

I PASSED THE MESSAGE TO THE MASTER TERMINAL.

Application PGM

Sending Message Over TCP/IP Link

36

IMS3

MSC

Processing System (Destination)

MSCIMS2

IMS1

CQS1

CQS2

IMSPlex1

PMTO

MSC

TCPIP

CF

Lterm

Application PGM

Operator

MSC Improvements

MSC TCPIP link is faster than VTAM link MSC bandwidth offers performance improvement of 50%-

60%. (This mode blocks multiple responses and messages into a single send)

Dynamic MSC makes MSC much easier to use and expand network

Most of our large IMS customers (including shared queue customers) are using MSC

Q & A

Thanks!