Silo-Based Architectures for High Availability Applications @PhpUk2017

Silo-Based Architectures for High Availability Applications @PhpUk2017

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. 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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Georgiana Gligor

February 17, 2017
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  1. 2.

    2 Georgiana Gligor ✤ Geek. Mother. Do-er. ✤ Crafting enterprise

    apps ✤ Large-Scale Application Architect ✤ PHP Cluj Meetup Organiser ✤ Systems Engineering PhD Student @gbtekkie gb@tekkie.ro
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    5 advantages and disadvantages AGENDA silos: a possible approach the

    need for high availability what is high availability (HA)?
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    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
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    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
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    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%
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    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
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    36 WHAT IS A SILO? ✤ frontend (e.g. Javascript SPAs)

    ✤ backend (e.g. PHP services) ✤ cache 1 silo = full setup of servers that deliver the end-to-end functionality
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    43 ADVANTAGES ✤ reuse familiar technology ✤ real A/B testing

    ✤ no BHUF requirements ✤ no disruption => brand loyalty ✤ lower Total Cost of Ownership ✤ simplify scalability
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    44 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
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    46

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    47 ✤ build situational awareness with clever monitoring ✤ automate

    outage detection ✤ powerful A/B testing TAKEAWAYS
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    48 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”