The document presents the advantages of using z/OS as a platform for API development and hosting, highlighting its reliability, scalability, and security. It emphasizes the mainframe's capability to efficiently manage high workloads and secure sensitive data while integrating seamlessly with modern applications through REST APIs. Additionally, it discusses the tools available for developing and deploying APIs, including the z/OS Connect and its compatibility with multiple subsystems.

1. InterConnect
2017
Why z/OS is a Great
Platform for Developing and
Hosting APIs
Teodoro Cipresso, IBM z/OS
Connect Developer
cipresso@us.ibm.com
Bruce Armstrong, IBM z/OS
Connect Offering Manager
armstrob@us.ibm.com
Session# HAW-3223
1 3/27/2017

2. 2 3/27/2017
Please note
IBM’s statements regarding its plans, directions, and intent
are subject to change or withdrawal without notice at IBM’s
sole discretion.
Information regarding potential future products is intended to
outline our general product direction and it should not be relied
on in making a purchasing decision.
The information mentioned regarding potential future products
is not a commitment, promise, or legal obligation to deliver
any material, code or functionality. Information about potential
future products may not be incorporated into any contract.
The development, release, and timing of any future features
or functionality described for our products remains at our sole
discretion.
Performance is based on measurements and projections
using standard IBM benchmarks in a controlled environment.
The actual throughput or performance that any user will
experience will vary depending upon many factors, including
considerations such as the amount of multiprogramming in
the user’s job stream, the I/O configuration, the storage
configuration, and the workload processed. Therefore, no
assurance can be given that an individual user will achieve
results similar to those stated here.

3. The Belief
3

4. The Reality
CICS
IMS
WebSphere
DB2z/OS Connect
API
API
API
MQ
44

5. Why z Systems?
• Mainframe applications are integral to business
• Their transactions and data access can be published as
fully RESTful APIs
• Modern z/OS is built with hybrid cloud and mobile
development in mind
• You can drive a CICS/IMS/DB2/MQ or other transactions
from a mobile or Cloud app
… without even knowing it
5

6. Connected Appliances
Partners
Websites
APIs
Trillions 2018+
Tablets
Internet TVs
Smartphones
Game Consoles
Connected Cars
• Provides sub-second response time, even
under extreme loads
Secure
Responsive
Scalable
• Enables in-transaction analytics
• Scalability – best vertical scalability on the
market to support millions of online users
• Security – has earned the highest level of
security certification
• Availability – 24x7x365
• Reliability – 99.999% uptime
The mainframe can take on this challenge
6

7. The New Mainframe: Home of
RAS, Security, Scalability,
Mobility, and Open API.
7 3/27/2017
“The New Mainframe has an unrivaled
ability to serve end users by the tens
of thousands, manage petabytes of
data, and reconfigure hardware and
software resources to accommodate
changes in workload—all from a single
point of control.”

8. 8 3/27/2017
The New Mainframe – Today and Tomorrow
• The mainframe’s popularity and longevity are owed to its
inherent reliability and stability.
• No other computing platform can claim as much continuous
improvement while maintaining backwards compatibility.
• Mainframes are ideal for the [hybrid] cloud, or wherever the
future takes us, as they are designed to support:
• Large numbers of users and applications that need concurrent
and efficient access to shared data.
• Very high-bandwidth communication to storage devices, other
mainframes, and the network.
• Reconfiguring of hardware and software without requiring a
scheduled outage in many cases.
Image credit: illumin.usc.edu

9. 9 3/27/2017
The New Mainframe – Reliability Availability Serviceability
• A system is said to exhibit “RAS characteristics” if:
• Hardware is self-checking and issues alerts when failure is
imminent or has already occurred.
• Failed hardware is automatically replaced by redundant
hardware without impacting the rest of the system.
• Software is extensively tested before being deployed.
• Software can be quickly updated when problems are detected
despite extensive testing.
• The overall system can recover from severe errors in software,
preventing an unplanned outage.
• The system can determine why a hardware or software failure
occurred, informing corrective next steps.

10. 10 3/27/2017
The New Mainframe – Reliability Availability Serviceability
• The mainframe and its associated software have evolved
such that months or even years can pass between outages.
• When the system is unavailable because of planned or
unplanned outages, the interruption is typically very brief.
• The remarkable availability of the mainframe, and ease with
which problems can be resolved, makes for a quite reliable
and serviceable system.
“IBM spent $1 billion developing a new refrigerator-sized
mainframe. It makes sense. For companies that require
100% uptime, public clouds simply aren't feasible.”
Timothy Green, The Motley Fool
https://www.fool.com/investing/general/2015/01/24/heres-why-ibm-is-still-building-mainframes.aspx

11. 11 3/27/2017
The New Mainframe – Security
• A secure system is protected through special hardware and
software, policies, and practices against data corruption,
destruction, interception, loss, or unauthorized access.
• Services provided by a secure system:
1. Authentication: are you who you say you are?
2. Authorization: are you allowed to do that?
3. Integrity: has the data been tampered with?
4. Privacy: is sensitive data encrypted?
5. Non-repudiation: we’re sure you did it!

12. 12 3/27/2017
The New Mainframe – Security
• The mainframe and its associated software provide
comprehensive security services that far exceed the basic
requirements of a secure system.
Authentication
Authorization
Integrity
Privacy
Non-repudiation
z/OS Cryptographic
Services
z/OS Network
Security Services
z/OS Security
Server (RACF)
z/OS System
Logger

13. 13 3/27/2017
The New Mainframe – Scalability
• The ease with which one can add capacity without disruption to
normal business processes or without incurring excessive
overhead is largely determined by the scalability of a system.
• In a scalable system, hardware and software continues to function
and remain performant as processors, memory, and storage are
added to handle an increased workload or removed in response to
a decreased workload.

14. 14 3/27/2017
The New Mainframe – Scalability
• Mainframes can significantly reduce TCO due to advanced
virtualization capabilities that allow many operating system
instances to run on a single mainframe.
• Up to 85 independent z/OS operating system instances can be run
simultaneously on a z13 through logical partitioning (LPARs).
• Linux on an IBM z13 mainframe system can support up to 8000
virtual machines which is ideal for large scale consolidation.
“…one modern mainframe can not only run its own
environment, but also virtualize hundreds or even
thousands of more pedestrian servers — all at the same
time. Think about that for a second. Have an explosive
growth in user activity? Which feels more scalable to you
— adding another thousand individual boxes, or one
more mainframe?”
“..mainframes have many, many more CPUs
running simultaneously than do smaller boxes, as
well as much more available memory. What this
means in scalability terms is that the mainframe
has power where it needs it, when it needs it, with
much fewer complications than trying to move
workloads around thousands of smaller servers.”
Caitlin Hughes, Advanced Software Products Group
http://aspg.com/reasons-why-mainframes-still-matter/#.WMMe72_ytEY

15. 15 3/27/2017
The New Mainframe – Mobility and Flexibility
• Developers like to take their work around with them, be it to the
cafeteria, to a coffee shop, on a plane…
• Like other makers, developers prefer to setup a workbench
where all the tools they need to do their job properly are
organized to their taste.
• Developers expect environments they create using their
workbench to be destructible, so that mistakes can be made,
recovered from, and learned from.
• Within their own workbench developers prefer to have full
authority over all the tools and their configuration, so they can
make progress without bothering other busy people.

16. 16 3/27/2017
The New Mainframe – Mobility and Flexibility
https://www.techvalidate.com/tvid/C99-3E2-1ED
“zD&T improved our development
and testing timeline and provided
stability and quality” Developer,
Large Enterprise Computer
Services Company

17. 17 3/27/2017
zD&T: Add Mainframe Development and Test Capacity
without increasing your MIPS
Note: This Program is licensed only for development and test of applications that run on IBM z/OS. The Program may not be used to run
production workloads of any kind, nor more robust development workloads including without limitation production module builds, pre-
production testing, stress testing, or performance testing.
Affordable off host development
and test environment
z/OS
COBOL, PL/I, C++, Java,
EGL, Batch, Assembler,
X86 PC or HX5 Blade
running Linux
IBM SoftLayer Infrastructure
zD&T
z Systems
Development and
Test Environment
(zD&T)
WAS
MQ
DB2
DT
CICS
IMS
RIT
UCD
RTC
IDz
zD&T helps address the following challenges:
• Insufficient mainframe Dev & Test LPAR
availability leads to defects and missed schedules
• Tightly controlled mainframe environment
prevents agile experimentation and prototyping
• High cost of mainframe development and test
hardware and software
• Skill gaps due to off shoring, outsourcing or the
majority of skills being near retirement
• Slow response time for off shore teams needing
development access
ZCON
“zD&T improved our development and testing
timeline and provided stability and quality” Developer,
Large Enterprise Computer Services Company

18. 18 3/27/2017
The New Mainframe – Open API
• To programmers, consuming APIs is a daily practice as most
products document APIs that can be called from applications.
• What we’re interested in here are REST APIs, which are
agnostic of hardware, OS, and programming languages.
• Why are REST APIs good for your business?
• Your developers can compose apps more quickly by
incorporating tested APIs instead of reinventing
functionality which will then need to be tested.
• Other businesses can compose apps that incorporate
APIs you’ve chosen to make public which can bring new
customers and increased revenue.
• The Open API specification (openapis.org), makes it easy for
people and machines to understand the capabilities of an API
without access to source code, online help,…,etc.
http://openapis.org

19. 19 3/27/2017
The New Mainframe – Open API
http://openapis.org

20. Introduction to the Open API
Specification & Tools
20 3/27/2017
“When an API is properly defined via Open
API, a consumer can understand and interact
with the remote service with a minimal
amount of implementation logic. Similar to
what interfaces have done for lower-level
programming, Swagger removes the
guesswork in calling the service.”

21. Open API (Swagger) Spec and Tools (openapis.org)
Swagger Editor
An editor for designing Swagger
specifications from scratch,
using a simple YAML structure.
Swagger UI
Use a Swagger specification to
drive your API documentation.
SDK Generators
Turn an API spec into client
SDKs or server-side code with
Swagger Codegen.
21

22. Swagger Editor – Develop an API Specification
Swagger Editor
An editor for designing Swagger
specifications from scratch,
using a simple YAML structure.
Swagger UI
Use a Swagger specification to
drive your API documentation.
SDK Generators
Turn an API spec into client
SDKs or server-side code with
Swagger Codegen.
22

23. Swagger UI – “Try out” an API
Swagger Editor
An editor for designing Swagger
specifications from scratch,
using a simple YAML structure.
Swagger UI
Use a Swagger specification to
drive your API documentation.
SDK Generators
Turn an API spec into client
SDKs or server-side code with
Swagger Codegen.
23

24. SDK Generators – Integrate or Implement an API
Swagger Editor
An editor for designing Swagger
specifications from scratch,
using a simple YAML structure.
Swagger UI
Use a Swagger specification to
drive your API documentation.
SDK Generators
Turn an API spec into client
SDKs or server-side code with
Swagger Codegen.
24

25. Compose APIs from Multiple z
Subsystems and Harness their
Unique Strengths.
25 3/27/2017
“z/OS Connect Enterprise Edition makes it
possible to create new value by enabling
the creation of APIs that bring together
multiple, disparate, z subsystem assets.”

26. 26 3/27/2017
Scenario
• A business analyst at the OfficeMix company
determines that an API which allows
consumers to browse for and order office
supplies is required to expedite development
of client-facing mobile and Web applications.
• Due to several mergers and acquisitions, the
OfficeMix company already has the required
application logic and databases, but they are
spread across multiple z subsystems.

27. 27 3/27/2017
Catalog Manager
IVP application
Phonebook
IVP application
ORDERS
New Table
OfficeMix API Multi-Subsystem Demo
Swagger UI
Swagger
Codegen
Test
Generate
Swagger
Client
3 services 1 API

28. 28 3/27/2017
Creating a CICS WOLA service – Configure

29. 29 3/27/2017
Creating a CICS WOLA service – Generate

30. 30 3/27/2017
Creating a CICS WOLA service – Deploy
// PROGRAM DFH0XCMN
// SERVICE BASED ON DFH0XCMN
// SERVICE BASED ON DFH0XCMN
// SERVICE BASED ON DFH0XCMN

31. 31 3/27/2017
Creating a CICS WOLA Service – Test

32. 32 3/27/2017
Creating a CICS WOLA Service – More Information
• z/OS Connect Enterprise Edition V2.0 Getting Started Guide, http://ibm.co/2nB50zl
• Develop an API to invoke a CICS service via WOLA, http://ibm.co/2nB8Qsl

33. 33 3/27/2017
Creating a DB2 REST Service – Configure

34. 34 3/27/2017
Creating a DB2 REST Service – Create a Database (Optional)

35. 35 3/27/2017
Creating a DB2 REST Service – Deploy (DB2ServiceManager)

36. 36 3/27/2017
Creating a DB2 REST Service – Get Details

37. 37 3/27/2017
Creating DB2 REST Client Services – Configure

38. 38 3/27/2017
Creating DB2 REST Client Services – Deploy

39. 39 3/27/2017
Creating DB2 REST Client Services – Test

40. 40 3/27/2017
Creating DB2 REST Client Services – More Information
• DB2 REST services, http://ibm.co/2nB1vc7

41. 41 3/27/2017
Creating an IMS REST Service – IMS Explorer

42. 42 3/27/2017
Creating an IMS REST Service – More Information
• Using the IMS service provider, http://ibm.co/2nB2IjF

43. 43 3/27/2017
Creating a z/OS Connect EE API – Design

44. 44 3/27/2017
Swagger
Client
/officemix/v1
/customers/{lastName}
add|get|update|deleteCustomer()
/catalog/items
getItems()
/catalog/items/{itemID}
getItem()
/catalog/order
placeOrder()
/orders
getOrders()
/orders/{orderID}
get|deleteOrder()
If you customize the Operation IDs when defining
your API using the z/OS Connect EE API Editor,
Swagger Codegen will produce helpful method
names in the generated client code.
{

45. 45 3/27/2017
Creating a z/OS Connect EE API – Deploy

46. 46 3/27/2017
Creating a z/OS Connect EE API – Test

47. 47 3/27/2017
Creating a z/OS Connect EE API – Test (cont’d)

48. 48 3/27/2017
Generate a Node.js Client – Swagger Editor

49. 49 3/27/2017
Generate a Node.js Client – Documentation

50. How to Handle the Impact of
Change in z Subsystem Assets
on z/OS Connect APIs.
50 3/27/2017
“The z/OS Connect EE API Editor helps you
deal with change in z subsystem assets by
providing impact analysis and
automatically integrating changes with
error feedback.”

51. 51 3/27/2017
Catalog Manager
IVP application
Phonebook
IVP application
ORDERS
New Table
OfficeMix API Impact Analysis Demo
Swagger UI
Swagger
Codegen
Test
Generate3 services 1 API
Deal with
change in
services
Swagger
Client

52. 52 3/27/2017