RELIABILITY ENGINEERING FOR ENTERPRISE SERVERLESS MASASHI TERUI @ JAWS DAYS 2018

SERVERWORKS CO.,LTD. + FREELANCER • Serverless Oji-san • Serverless Framework Plugin Developer • Serverlessconf Tokyo 2016/2017 speaker • Remote worker (in Sapporo) • The best Cloud Engineer in Hokkaido!! (Ͱ͋Γ͍ͨʣ MASASHI TERUI ARCHITECT / DEVELOPER

AGENDA SERVERLESS ͬͯͳΜ͚ͩͬʁ 1 6 2 7 3 8 4 9 5 10 SERVERLESS ͷ৴པੑͱ͸ʁ SERVERLESS ͷΑ͋͘Δ՝୊ SERVERLESS Λ࣮ମΛଊ͑Δ RELIABILITY ߟ͑ํ RELIABILITY ઃܭฤ RELIABILITY ࣮૷ฤ RELIABILITY ؂ࢹฤ SUMMARY ੈքΛ޿͛Δ SERVERLESS ͸ಛผ͡Όͳ͍

SERVERLESSͬͯͳΜ͚ͩͬʁ WHAT IS

CNCF SERVERLESS WHITEPAPER V1.0 • Serverless computing refers to the concept of building and running applications that do not require server management • A platform may provide one or both of the following: • Functions-as-a-Service (FaaS) • Backend-as-a-Service (BaaS) • Products or platforms deliver the following benefits to developers: • Zero Server Ops • No Compute Cost When Idle 
 https://github.com/cncf/wg-serverless/tree/master/whitepaper

SERVERLESS IS NOT GLUE IN ENTERPRISE APPLICATION ”THE ORCHESTRATOR MANAGES THE TRADES USING A GRAPH OF STATES”

SERVERLESS CLOUD NATIVE LANDSCAPE

BUT I PREFER THIS ONE https://www.slideshare.net/acloudguru/ant-stanley-being-serverless

SERVERLESS USE CASES (FROM CNCF WP) • Asynchronous, concurrent, easy to parallelize into independent units of work • Infrequent or has sporadic demand, with large, unpredictable variance in scaling requirements • Stateless, ephemeral, without a major need for instantaneous cold start time • Highly dynamic in terms of changing business requirements that drive a need for accelerated developer velocity • Non-HTTP-centric and non-elastic scale workloads that weren’t good fits for an IaaS, PaaS, or CaaS solution (Event Driven workloads)

“There are many workloads that are stateful and/or not easy to parallelize” ͱࢥͬͯ·ͤΜ͔ʁ “Asynchronous and Event Driven processing is too difficult for humans”

SERVERLESSͷ৴པੑͱ͸ʁ Reliability

RELIABILITY(RASIS) ࡉ෼Խ͢Δͱ৭ʑ͋Δ • Reliability • Availability • Serviceability • Integrity • Security ͜͜Ͱ͸ҎԼͷΑ͏ʹఆٛ
 ʮReliability = ޿ٛͷ৴པੑ(RASIS)ʯ Reliability Availability Serviceability Integrity Security Reliability

IS SERVERLESS DIFFICULT TO GUARANTEE THE RELIABILITY? • Strongly depends on FaaS platform and BaaS products • Lose the business continuity (Reliability, Availability) • Distributed Instances • Lose the traceability (Serviceability) • Hard to develop • All become functions (Serviceability) • NoSQL matches better than RDB (Integrity)

SERVERLESSͷΑ͋͘Δ՝୊ i s s u e s

FaaSͷΑ͋͘Δ՝୊ • How to test the functions? • Granularity of the functions • Messaging between the functions and backends • Handling request and response (Error Handling) • Log Aggregation, Traceability • Monitoring

BaaSͷΑ͋͘Δ՝୊ • How to choose the services? • Fault Tolerance • Monitoring

SERVERLESSͷ࣮ମΛଊ͑Δ Mechanism HINT

MECANISM OF FAAS

SERVERLESS PROCESSING MODEL https://github.com/cncf/wg-serverless/tree/master/whitepaper#detail-view-serverless-processing-model ॲཧͷશମ૾Λ௫Ή Πϕϯτιʔε͔ΒͷΠϕϯτॲཧཁٻΛ ଟ਺ͷΠϯελϯε্ͷFunction͕෼ࢄॲཧ

THE INTERNAL FLOW OF PROCESSING https://github.com/apache/incubator-openwhisk/blob/master/docs/about.md#the-internal-flow-of-processing Πϕϯτ(HTTP)͕ॲཧ͞ΕΔྲྀΕΛ௫Ή ετϦʔϜ΍ΩϡʔΛڬΜͰ෼ࢄॲཧ͢Δͷ͕جຊ ֎͔ΒݟͯಉظͰ΋த͸ඇಉظ͔ͭ෼ࢄ

THE FUNCTIONS THAT INVOKED ASYNCHRONOUS IN THE CONTAINERS FaaS is… ίϯςφ಺Ͱඇಉظʹݺͼग़͞ΕΔؔ਺

WHAT IS BAAS?

FROM OWNERSHIP TO USE SERVICES Ϋϥ΢υʹΑͬͯαʔό͕ॴ༗͔Βར༻΁ ͞Βʹϛυϧ΢ΣΞ΍ϥΠϒϥϦ΋ར༻΁ BaaSΛ࢖͏ͷ͸ͦ͏͍͏ࣗવͳྲྀΕ

FULLY MANAGED AND ABSTRACTED MIDDLEWARES AND LIBRARIES BaaS is… ϑϧϚωʔδυ͔ͭந৅Խ͞ΕͨMW΍ϥΠϒϥϦ

SERVERLESS͸ಛผ͡Όͳ͍ is not special

CONSTITUTED OF THE ABSTRACTED FUNCTIONS AND MIDDLEWARES Serverless is… ந৅Խ͞ΕͯΔ͚ͩͰؔ਺ͱMWͰͰ͖ͯΔ

WE CAN MAKE RELIABLE SERVERLESS APPLICATION SO… ৴པੑ͸࡞ΕΔʂ

RELIABILITYͷߟ͑ํ Method of thinking

RELIABILITYͷߟ͑ํ • Make the reliability by myself • Serverless will help you, but will not protect your business • Think simple • Apply generally development/operation practices • If you can't apply the practices, take care of the serverless mechanism • Keep simple • Don't be afraid that increase the number of the functions • We should be afraid complicated architecture • Change your mind as a software • Everything is part of your application

RELIABILITY ઃܭ Architecting

ALL EVENTS FLOWS IN THE SAME DIRECTION Πϕϯτ(σʔλ)͸ಉ͡ํ޲ʹྲྀ͢ ݁Ռ͕ඞཁͳΒಉظͰฦͣ͞ औΓʹߦ͔ͤΔ

ALL EVENTS FLOWS IN THE SAME DIRECTION • They will be naturally Asynchronous and Functional • Asynchronous processing is Retriable • Functional processing is Reproducible • The clients get the results by myself • However, polling is not good choise... • Pushing is better choice • Can we be happy with AppSync? (Pushing via Websocket)

UNIFY THE ENDPOINTS BETWEEN THE SERVICES αʔϏεؒͷΤϯυϙΠϯτ͸ू໿͢Δ ϥοϓͯ͠ू໿͠ίϯτϩʔϧΛಘΔ

UNIFY THE ENDPOINTS BETWEEN THE SERVICES • Microservices • Separate the services by the domains (One BaaS is one of your service) • The endpoint of the service is not unique, it has the endpoints for each operations • Wrap the endpoints to abstract them • Like a “MySQL Server” and “libmysql” • Do you call “libmysql” directly? • You can make Failover/Failsafe mechanism • Like a Reverse Proxy • Do you connect to multiple “Read replicas” from “each app servers”? • Trafic controlling, Caching

ALL SERIES OF EVENTS HAVE THE SAME ID Ұ࿈ͷॲཧʹ͸ಉ͡IDΛ෇༩ ͦΕΛҾ͖ճ͢͜ͱͰIDͰτϨʔεͰ͖Δ ͜ͷID͸༷ʑͳ੍ޚʹ΋࢖͑Δ

ALL SERIES OF EVENTS HAVE THE SAME ID • Log Aggregation • A series of events can be traced by the ID • Monitor the progress • Log all event messages • Execution control • At least once -> Exactly once • e.g. DynamoDB Conditional Writes • Make it easy to implement with something like a decorator

DATA MODELING • Become the friend with DynamoDB • Distributed by Partition Key and Indexed(B-tree) by Sort Key, LSI • GSI is a projection of sorted(indexed) data • The consistency can be guaranteed without ACID transaction • Denormalization • Strong consistency reading, 
 Conditional Writing • There are some difficult situation • Write asynchronous to RDB

RELIABILITY ࣮૷ Implementation

GRANULARITY OF THE FUNCTIONS •Testable!! • Unit testing is justice in the serverless world • Make the dependencies of other services are replaceable • Would be replaceable to the mocks • Easy to Failover/Failsafe

HOW TO TEST THE FUNCTIONS • Unit testing is justice in the serverless world (2ճ໨) • Deploy a new environment if the mocks are not enough at integration testing • It is easy with some frameworks (e.g. Serverless, SAM) • The services outside of AWS are needed to be easily to deploy (via API) • Continuous E2E testing with traceable ID • It become a monitoring

RELIABILITY ؂ࢹ Monitoring

RELIABILITY MONITORING • The greatest monitoring is the notifications from the application • Be sure to catch the errors and notify them • Collect the metrics of the services • CloudWatch • This is a condition to choice the services outside of AWS • Continuous E2E testing with traceable ID

SUMMARY

“SERVERLESS IS NOT SPECIAL” THANKS!! “MAKE THE RELIABILITY BY MYSELF” “THINK SIMPLE, KEEP SIMPLE” “EVERYTHING IS PART OF YOUR APPLICATION” “LET'S EXPAND SERVERLESS WORLD”

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