[SCaLE16x] Silo-Based Architectures for High Availability Applications

High availability is becoming a de-facto requirement of today's applications. Customer-facing IT failures mean directly losing customer revenue and trust, as users have grown accustomed to easily switching service providers for more reliable ones. Lack of internal systems availability block employee productivity and add to the financial burden. Thus, it is critical to have a healthy, performant, resilient IT structure serving as a backbone of conducting your business. But there are no textbook solutions to achieving five 9s availability. Data redundancy, computing clusters, load balancing, fail-over mechanisms, each of these individually addresses one potential issue, but none treats systems in your organisation holistically for maximising business revenue.

Not everyone has the financial and technical ability to use the latest and greatest CDN and offload their high-availability requirements to such 3rd parties. This is where smartness comes into play, and my goal is to show you a different way of architecting an application, one that is centered around solving your own business needs without a huge additional cost. We have devised this solution while working on a very large US airline, using open-source technologies, to meed the Black Friday & Cyber Monday traffic requirements.

Silos are a clever method of grouping servers in such a way that they can be scaled both horizontally and vertically, depending on the actual application needs. Most importantly, it frees you from over-optimizing the architecture upfront, by allowing fine adjustments easy to integrate in your Agile workflow.

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1. FOR HIGH AVAILABILITY APPLICATIONS SILO-BASED ARCHITECTURES Georgiana Gligor / Tekkie Consulting / @gbtekkie
2. @gbtekkie SCaLE 16X 2 ✤ Geek. Mother. Do-er. ✤ on LAMP/LEMP stack since 2003 ✤ Architecture / DevOps consultant ✤ RomaniaPHP Organizer ✤ PhD Student @gbtekkie gb@tekkie.ro GEORGIANA GLIGOR
3. @gbtekkie SCaLE 16X 3 advantages and disadvantages silos: a possible approach the need for high availability what is high availability (HA)? AGENDA
5. @gbtekkie SCaLE 16X 5 https://youtu.be/MQm5BnhTBEQ
6. 6 Software industry is built around anticipating change.
7. 7 anticipate accommodate vs
8. TYPICAL APPLICATION
9. @gbtekkie SCaLE 16X 9
11. @gbtekkie SCaLE 16X master Frontend Business Logic Frontend Frontend Browser internet Load balancer slave reads writes 11 ADJUSTING
12. @gbtekkie SCaLE 16X master Frontend Business Logic Frontend Frontend Browser internet Load balancer slave reads writes 12 ADJUSTING redundancy
13. @gbtekkie SCaLE 16X master Frontend Business Logic Frontend Frontend Browser internet Load balancer slave reads writes 13 ADJUSTING resilience
14. @gbtekkie SCaLE 16X 14 TYPICAL LAYERING
15. @gbtekkie SCaLE 16X 15 APPLICATION ARCHITECTURE
16. HIGH AVAILABILITY
17. @gbtekkie SCaLE 16X 17 Ability to access the system: ✤ retrieve information ✤ alter information ✤ send new data AVAILABILITY
18. https:/ /flic.kr/p/dkasBz
19. @gbtekkie SCaLE 16X 19 THE 9s DANCE Uptime Downtime (per year) 90.000 % 36.50 days one nine 99.000 % 3.65 days two nines 99.900 % 8.76 hrs three nines 99.950 % 4 hrs 23 mins 99.990 % 52.56 mins four nines 99.999 % 5.26 mins five nines
20. @gbtekkie SCaLE 16X 20 THE 9s DANCE Uptime Downtime (per year) 90.000 % 36.50 days 99.000 % 3.65 days 99.900 % 8.76 hrs 99.950 % 4 hrs 23 mins Amazon SLA 99.990 % 52.56 mins four nines 99.999 % 5.26 mins five nines
21. @gbtekkie SCaLE 16X 21 IMPACT $ 144,000 / hour 3600 $ 40 / sec * =
22. @gbtekkie SCaLE 16X 22 USER BEHAVIOUR amazon facebook youtube Alexa Rank 6 3 2 daily time on site 12:07 mins 19:27 mins 23:44 mins daily pageviews / visitor 11.83 9.38 12.84 bounce rate 21 % 29 % 33 %
23. @gbtekkie SCaLE 16X 23 HIGH AVAILABILITY TRIANGLE cost complexity risk
24. @gbtekkie SCaLE 16X 24 DOWNTIME scheduled ‣ you unscheduled ‣ you ‣ others
25. @gbtekkie SCaLE 16X 25 HAPPENS TO THE BEST
26. @gbtekkie SCaLE 16X 26 MICHAEL JACKSON
27. H.A. SYSTEM CHARACTERISTICS
28. https://flic.kr/p/quMmFw NO SINGLE POINT OF FAILURE
29. https://flic.kr/p/RLKw8z RELIABLE CROSSOVER
30. DETECT FAILURES AS THEY OCCUR
31. @gbtekkie SCaLE 16X 31 HA BEST PRACTICES 1. no single points of failure 2. stateless application design 3. automate infrastructure for consistency & reliability 4. clever monitoring and alerting 5. geographically distribute your machines 6. keep spare capacity to meet increasing demand
32. 32 A man’s got to know his limitations. - Dirty Harry
33. SILOS
34. @gbtekkie SCaLE 16X 34 TRY UPGRADE TO PHP7
35. @gbtekkie SCaLE 16X 35 WHAT IS A SILO? ✤ frontend (SPAs, PWAs, etc) ✤ backend (e.g. PHP services) ✤ data (including cache) 1 silo = full setup of servers that deliver the end-to-end functionality
36. @gbtekkie SCaLE 16X 36 WHAT IS A SILO?
37. @gbtekkie SCaLE 16X 37 SILO-BASED ARCHITECTURE
38. @gbtekkie SCaLE 16X 38 MULTIPLE CACHES
39. @gbtekkie SCaLE 16X 39 A/B TESTING
40. @gbtekkie SCaLE 16X 40 GEOGRAPHICAL DISTRIBUTION
41. @gbtekkie SCaLE 16X 41 LIVE UPGRADES
42. @gbtekkie SCaLE 16X 42 ADVANTAGES ✤ reuse familiar technology ✤ real A/B testing ✤ no BHUF requirements ✤ no disruption => brand loyalty ✤ lower Total Cost of Ownership ✤ simplify scalability
43. @gbtekkie SCaLE 16X 43 DISADVANTAGES ✤ needs razor-sharp DevOps team ✤ small increase in hardware costs on kick-off ✤ adds complexity to the monitoring layer ✤ reconsider traceability ✤ different bug reproducing and hunting
44. @gbtekkie SCaLE 16X 44 TAKEAWAYS
45. @gbtekkie SCaLE 16X 45 ✤ build situational awareness with clever monitoring ✤ automate outage detection ✤ powerful A/B testing TAKEAWAYS
46. @gbtekkie SCaLE 16X 46 FURTHER READING ✤ Wikipedia HA page ✤ OpenStack’s HA concepts ✤ Merge Hemo report from FDA ✤ USA Presidential Policy Directive 21 ✤ “Beyond Legacy Code” book ✤ TechCrunch’s summary of sites affected by Michael Jackson’s death ✤ Netflix lessons learned after AWS outage ✤ Netflix Chaos Monkey source code ✤ Brian Adler’s talk on “Architecting for High Availability and Multi-Cloud”
47. ‹#› Questions? } Efficient architecture. Performance oriented. AI enhanced. dev@tekkie.ro