Presenters: Matthew Skelton and Rob Thatcher, Skelton Thatcher Consulting Webinar: Operability is all about making software work well in Production. In this webinar, we explore practical, tried-and-tested, real world techniques for improving operability with many kinds of software systems, including cloud, Serverless, on-premise, and IoT: logging with Event IDs, Run Book dialogue sheets, endpoint healthchecks, correlation IDs, and lightweight User Personas. Target audience: Software Developer, Tester, Software Architect, DevOps Engineer, Delivery Manager, Head of Delivery, Head of IT. Benefits: Attendees will gain insights into operability and why this is important for modern software systems, along with practical experience of techniques to enhance operability in almost any software system they encounter.

1. Practical Operability
Techniques for Teams
Matthew Skelton & Rob Thatcher
Skelton Thatcher Consulting
skeltonthatcher.com / @SkeltonThatcher
Unicom Seminars – webinar – 28 September 2017

2. Today
40 mins: operability techniques
10-15 mins: questions

3. Today
What is operability?
Modern logging
Run Book dialogue sheets
Endpoint healthchecks
Correlation IDs
User Personas for dashboards

4. Training
1-day tutorial with exercises
Book via Unicom: http://www.unicom.co.uk/workshops.html

5. You
Software Developer
Tester / QA
DevOps Engineer
Team Leader
?

6. Operability:
use modern logging, Run Book
dialogue sheets, endpoint
healthchecks, correlation IDs,
and user personas as
team collaboration techniques

8. About us
Co-founders at Skelton Thatcher Consulting
Matthew Skelton Rob Thatcher

9. Team-first digital transformation
30+ organisations
UK, US, EU, India, China

10. We build modern capabilities
by mentoring your teams

11. Team Guide to
Software Operability
Matthew Skelton & Rob Thatcher
skeltonthatcher.com/publications
Download a free sample chapter

12. Practical Operability
Techniques for Teams

13. What is operability?

14. Operability
making software work well
in Production

16. Logging with Event IDs

18. logging with Event IDs
reduce time to detect problems
increase team engagement
increase configurability
enhance collaboration
#operability

19. search by
event
Event ID
{Delivered,
InTransit,
Arrived}

20. transaction
trace
Correlation ID
612999958…

21. How many distinct event
types (state transitions)
in your application?

23. represent distinct states

24. enum
Human-readable sets:
unique values, sparse,
immutable
C#, Java, Python, node
(Ruby, PHP, …)

25. Technical
Domain
public enum EventID
{
// Badly-initialised logging data
NotSet = 0,
// An unrecognised event has occurred
UnexpectedError = 10000,
ApplicationStarted = 20000,
ApplicationShutdownNoticeReceived = 20001,
MessageQueued = 40000,
MessagePeeked = 40001,
BasketItemAdded = 60001,
BasketItemRemoved = 60002,
CreditCardDetailsSubmitted = 70001,
// ...
}

26. BasketItemAdded = 60001
BasketItemRemoved = 60002

27. log using Event IDs
with a modern
‘structured logging’ library

28. Example: video processing
On-demand processing of TV
advertisements
Ad-agency  TV broadcaster
High throughput
Glitch-free video & audio

29. Storage I/O
Worker Job
Queue
Upload

32. Example: video processing
Discover processing bottlenecks
Trigger alerts via LogEntries /
HostedGraphite
Report on KPIs
Target areas for improvement

33. Run Book dialogue sheets

35. Run Book dialogue sheets
Checklists: typical operational
considerations
Team-friendly exploration

36. System characteristics
Hours of operation
During what hours does the service or system actually need to operate? Can portions or features of the
system be unavailable at times if needed?
Hours of operation - core features
(e.g. 03:00-01:00 GMT+0)
Hours of operation - secondary features
(e.g. 07:00-23:00 GMT+0)
Data and processing flows
How and where does data flow through the system? What controls or triggers data flows?
(e.g. mobile requests / scheduled batch jobs / inbound IoT sensor data )
…

37. http://runbooktemplate.info/

38. runbooktemplate.infoRun Book dialogue sheets

39. Endpoint healthchecks

41. endpoint healthchecks
Every runnable app/service/daemon
exposes /status/health
An HTTP GET to the endpoint returns:
200 – "I am healthy"
500 – "I am sick"

42. endpoint healthchecks
For databases and other non-HTTP
components, run a lightweight HTTP
service in front of the component
200 / 500 responses

43. https://github.com/Lugribossk/simple-dashboard

44. Correlation IDs

46. ‘Unique-ish’ identifier for each request
Passed through downstream layers

47. Unique-ish ID

48. Synchronous HTTP:
X-HEADER e.g. X-trace-id
X-trace-id: 348e1cf8
If header is present, pass it on
(Yes, RFC6648, but this is internal only)

49. Asynchonous (queues, etc.):
Message Attributes, name:value pair
e.g. "trace-id":"348e1cf8"
AWS SQS: SendMessage() / ReceiveMessage()
Log the Correlation ID if present

50. Example: electronic trading
High speed, low latency
Trading options & derivatives
Connected to stock exchanges
Sub-millisecond timings
> £1 million per day traded

54. Correlations IDs for trading
Evidence for timely operation
Help identify bottlenecks
Target areas for perf tuning
Identify race conditions
Increase operability

55. Lightweight user personas

57. Lightweight user personas:
Ops Engineer
Test Engineer
Build & Deployment Engineer
Service Owner

58. http://www.keepitusable.com/blog/?tag=alan-cooper

59. https://www.geckoboard.com/blog/visualisation-upgrades-
progressing-towards-a-more-useful-and-beautiful-dashboard/

60. Lightweight user personas:
What data does the User Persona
need visible on a dashboard in order
to make decisions rapidly & safely?

61. Summary

62. Operability
making software work well
in Production

63. logging with Event IDs
use enum-based Event IDs to
explore runtime behaviour
and fault conditions

64. Run Book dialogue sheets
explore and establish
operational requirements as
a team, around a physical
table, together

65. endpoint healthchecks
HTTP 200 / 500 responses to
/status/health call with
JSON details – good for
tools and humans

66. Correlation IDs
trace execution using
correlation IDs:
synchronous (HTTP X-trace-id)
async (SQS MessageAttribute)

67. lightweight user personas
explore the needs of
different roles for rapid
decisions via dashboards

68. Operability
use modern logging, Run Book
dialogue sheets, endpoint
healthchecks, correlation IDs,
and user personas as
team collaboration techniques

69. Team Guide to
Software Operability
Matthew Skelton & Rob Thatcher
skeltonthatcher.com/publications
Download a free sample chapter

70. Training
1-day tutorial with exercises
Book via Unicom: http://www.unicom.co.uk/workshops.html

71. Questions?
via the webinar chat tool
via Twitter: @SkeltonThatcher
via email: questions@skeltonthatcher.com
Unicom Seminars: info@unicom.co.uk

72. Resources
• Training: Practical Operability for Developers and Testers – led
by Matthew Skelton and Rob Thatcher – 1-day workshop –
http://www.unicom.co.uk/practical-operability-for-developers-
and-testers.html
• Team Guide to Software Operability by Matthew Skelton and Rob
Thatcher (Skelton Thatcher Publications, 2016)
http://operabilitybook.com/
• Run Book template & Run Book dialogue sheets
http://runbooktemplate.info/

73. thank you
@SkeltonThatcher
skeltonthatcher.com