1. Providing Application High Availability
Stephanie Balaouras
Principal Analyst
Forrester Research

2. Ground Rules & Expectations
House Keeping!
All teleconference lines are open...
Mute yourself when not speaking and don’t put call on ‘hold’.
Collaborate!
This is a discussion, not a presentation…
Ask questions, make comments and share experiences.
And beware, Forrester may call on you!
Are we in a ‘rabbit hole’?
If the conversation has gone down a substantial ‘rabbit hole’…
… Forrester will interject, but you decide whether or not to persist.

3. Agenda Understanding disaster recovery and availability
Measuring availability
Availability strategies
Recommendations

4. Definition: disaster recovery (DR)
Focuses on recovery procedures of critical IT systems following a significant disaster event or disruption that renders the primary site unavailable
Position: After the title slide.
Focus: These points should focus on ways to 1) cut costs, and/or 2) mitigate risks.
Narrative and flow:
The three bullets should build.
Since this is intro slide, we should not go into details here – just tell them what we’re going to tell them.

5. Definition: high availability (HA)
Focuses on the technology and processes to prevent application/service outages at the primary site or in a specific IT system domain

6. HA and DR requirements

7. Definition: continuous availability
Combines DR preparedness and high availability strategies to ensure IT service availability whether there is a system or site failure

8. Sources of service outages
Apps
Unplanned downtime
Planned downtime
Data integrity
(data corruption, bugs)
Hardware upgrades (servers, storage, networks etc.)
Data center/facilities failures
(extreme weather, power outages, manmade events.)
Software upgrades (OS, DB, app)
Maintenance (backups, patches)
Hardware failures (servers, storage, networks etc.)
Process failures
(human error, coding errors)
Data migrations

9. Agenda Understanding disaster recovery and availability
Measuring availability
Availability strategies
Recommendations

10. Availability focuses on service, not elements
Availability is the aggregation of all elements supporting the IT service.
Most components spec to % availability
Combined IT service availability would fall below %
Scheduled downtime is a critical part of the availability design
Most downtime is planned!

11. Availability is more than just “9”s
“9”s are misleading
Consider 99.9% availability (8 hours/year outage for 24x7), What is the difference between:
8 AM to 4 PM on the last Friday of the quarter
Biweekly outages of 30 min at 4 AM local time
Timing and duration are more important than total downtime
Well written SLAs must take all these factors into account

12. Availability metrics ITIL availability management
Availability of IT services compared to agreed upon SLAs
Duration of disruptions to IT services
Number of disruptions to IT services
Number of infrastructure components with availability monitoring
Number implemented measures to improve availability
Chip

13. Agenda Understanding disaster recovery and availability
Measuring availability
Availability strategies
Recommendations

14. Recovery time objective (RTO)
Local HA options
Seconds
FT hardware
FT VMs
Clustering
Local standby
Recovery time objective (RTO)
Restart VMs
Minutes
This is the data protection continuum today. It ranges from continuous data protection technologies to traditional backup to tape.
Which technology you select or incorporate into your overall data protection strategy is a function of two things: Your recovery time and recover point objectives and how much money your willing to spend.
Your recovery time objective or RTO is a measure of how quickly you need to recover from a business disruption such as a hardware failure, software failure, human error or some other type of disruption. For industries that can measure their cost of downtime in millions of dollars per hour or may have mandate by government body such as the SEC, their RTO must be near instantaneous.
Your recovery point objective or RPO is your sensitivity to data loss. So for example, a trading system at a financial institution may have a RPO of zero data loss – because any data loss could mean the loss of millions of dollars.
The more stringent your RTO/RPO the more you require a disk-based solution like continuous data protection but the more this type of solution will cost you.
In order to come up with the most cost-effective data protection strategy, you need to determine the RTO/RPO for your business applications and data sets and determine what you are willing to spend to support that.
So to help you do that, let’s spend some time on the next couple of slides talking about the characteristics of disk and tape based solutions and give you a high-level framework for incorporating the two.
System backup and restore
Hours
Less
More
Cost

15. IT service continuity (DR) options

16. Agenda Understanding disaster recovery and availability
Measuring availability
Availability strategies
Recommendations

17. Recommendations Downtime isn’t just the result of disasters
Make availability a part of every enterprise architecture, app development and IT infrastructure decision
The most seamless form of continuous availability is baked into the application
Preventing failures by architecture/design is cheaper than providing recovery for poorly designed applications

18. Recommendations (cont.)
Design applications for availability
Use reliable elements — server, storage, OS, etc.
Select HA and DR options for critical systems
Scrutinize operational process to reduce human error
Make availability a key component of acceptance testing

19. Thank You! Megan O'Donoghue Forrester Research, Inc. +1 617/613-6059
Stephanie Balaouras
Forrester Research, Inc.
Karen Popeo
Forrester Research, Inc.
+1 617/
Scott Sheehy
Forrester Research, Inc.
+1 617/