Upgrade to Pro — share decks privately, control downloads, hide ads and more …

Experiences with Microservices at Tuenti

Tuenti
June 26, 2015

Experiences with Microservices at Tuenti

This is the talk Aarón Fas and Andrés Viedma presented in the JBcnConf 2015 telling their experiences at Tuenti using a distributed architecture of microservices.

Tuenti

June 26, 2015
Tweet

More Decks by Tuenti

Other Decks in Programming

Transcript

  1. Who did you say these guys are? Andrés Viedma @andres_viedma

    Aarón Fas @aaronfc Java dinosaur Useless gadgets buyer
  2. Microservices… again… (and take a shot) ❖ Distributed, independently deployable

    components ❖ Well defined interfaces ❖ Simple communication interface (HTTP?) ❖ Each service has its own DB ❖ Each service has its own source repository
  3. Microservices… again… (and take a shot) ❖ Distributed, independently deployable

    components ❖ Well defined interfaces ❖ Simple communication interface (HTTP?) ❖ Each service has its own DB ❖ Each service has its own source repository THAT IS SOA !!!
  4. Microservices… again… (and take a shot) ❖ Distributed, independently deployable

    components ❖ Well defined interfaces ❖ Simple communication interface (HTTP?) ❖ Each service has its own DB ❖ Each service has its own source repository Is that important enough to deserve a new name???
  5. Mixing technologies ❖ Allows using different languages ❖ Different platform

    versions ❖ Incremental technology changes / evolution
  6. Separation of responsibilities ❖ Forces separation of responsibilities ➢ Subsystems

    with well defined facades ➢ Different source repositories
  7. Separation of responsibilities ❖ Forces separation of responsibilities ➢ Subsystems

    with well defined facades ➢ Different source repositories YOU DON’T NEED MICROSERVICES! USE JARS !!!
  8. Continuous deployment «Our highest priority is to satisfy the customer

    through early and continuous delivery of valuable software.» «The best architectures, requirements, and designs emerge from self-organizing teams.» -- Principles of the Agile Manifesto
  9. Continuous deployment «Our highest priority is to satisfy the customer

    through early and continuous delivery of valuable software.» «The best architectures, requirements, and designs emerge from self-organizing teams.» -- Principles of the Agile Manifesto 1 Service => 1 Team? Better than Continuous delivery!: Continuous deployment Team responsible of the deployments?
  10. Beware! High costs ❖ No transactions! ➢ Distributed tx? ❖

    Requires a much more complex infrastructure ❖ Difficult integration testing
  11. For us: Seemed like a good idea ❖ We have

    small self-organized teams => Continuous deployment is a reality ❖ We wanted Java, we had PHP ❖ Strong SRE / DevOps team ❖ Our software was intended mainly to access 3rd parties => transactions not possible anyway
  12. Existing libraries ❖ No PHP implementation ➢ Avro, Etch, Netflix

    stack ❖ Only serialization ➢ Protocol buffers ❖ Didn’t exist or were too new ➢ Cap’n Proto, gRPC ❖ Thrift? ➢ Good option, but a lot of PHP boilerplate
  13. TService ❖ Own abstraction layer - RPC based ❖ Basic

    implementation: JSON-RPC ❖ Interface Definition Language (IDL) ❖ Generates Java / PHP / Erlang: ➢ Interchange objects ➢ Client ➢ Server stub
  14. TService IDL /** * Manages the transfer of balance between

    subscriptions. * @version 1 */ interface BalanceTransferService { /** Transfer money from one subscription to another one. */ String transfer(Donation donation) throws NoSuchSubscriptionException; (...) } /** Donation between two subscriptions. */ class Donation { /** Id of the donor */ long from; /** Amount of money to transfer */ int amount; (...) } class NoSuchSubscriptionException extends Exception { int code = 100; } Java???
  15. TService Versioning Interface v1 Service Client 1 Client 2 (compatible

    changes) • New methods • New fields in objects • New parameters in methods • Delete methods / parameters / fields
  16. XConfig ❖ Own configuration system ❖ YAML files based ❖

    Git repository ❖ Overriding system: by env, common / service ❖ Hot reloading ➢ Everything adjusts to changes: even DB pools! ➢ No restart required
  17. Async jobs TService request processing Enqueue job Queued jobs Executor

    thread pool Cron jobs Cron jobs programming in config
  18. Feature disabling ❖ Activation / deactivation of features by config

    ➢ Is the new development risky? ➢ Is the rest of services / environment ready for the change? ❖ Partial activation of a feature for a % of users ➢ Incremental activation of an optional risky change ➢ A / B tests
  19. Integration tests ❖ Custom JUnit runner ➢ Bootstraps the platform

    ➢ Cleans / restarts the local database ➢ Allows the use of @Inject in tests ➢ Allows overriding in dependency injection => inject mocks of the other services ❖ Uses special, “development” XConfig repo
  20. Monitoring, a priority ❖ What is happening or has happened?

    ➢ Logs ➢ Metrics ➢ Alarms ❖ Distributed architectures are much more difficult to track
  21. Logging ❖ Logging library in Java? ➢ Log4j ❖ We

    needed full details ➢ Filters to expand/simplify information logged ➢ Multiple appenders logged into distinct storages
  22. ❖ Following call’s path (TService calls logging) Logging ServiceA ServiceB

    ServiceC GlobalID = 100 RequestID = 1 GlobalID = 100 RequestID = 2 GlobalID = 100 RequestID = 3 Benefits • Locate in/out for calls • Get all interactions
  23. Metrics ❖ We graphs ➢ As easy as possible to

    track new metrics ❖ Do not reinvent the wheel ➢ Already using StatsD/Graphite on PHP side ❖ What are we tracking? ➢ Basic monitoring metrics added by the platform ➢ Metrics from Tomcat JMX ➢ Metrics related to business
  24. Alarms ❖ Graphs are ok, but we don’t have people

    24x7 staring at them. ➢ We need notifications ❖ Different things to monitor ➢ SQL queries ➢ Graphite metrics ➢ HTTP requests ➢ ...
  25. Alarms ❖ Created our own alarms system ➢ Multiple data

    sources and easily extensible ➢ Quick edition of conditions ➢ Observers for alarms ❖ We ended up using mainly ➢ MySQL and Graphite data sources ➢ Java Expression Language on config checkers ➢ Email notifications
  26. Cabot ❖ Benefits of using Cabot ➢ Friendlier UI than

    config files ➢ No dependency on the service monitored ➢ Opensource and many integrations
  27. Alarms ❖ Where are we heading now? ➢ Moving now

    most Graphite alarms to Cabot ➢ Replacing thresholds with dynamic expectations (Holt Winters) ❖ It is still the main alarms platform being used
  28. Don’t get blocked for too long ❖ Concurrent requests: don’t

    wait for free threads ➢ Own Rate limit mechanism ➢ Tune container thread pool size ➢ Tune database pool (and other possible blocking pools) ❖ Tune clients timeout ➢ It may depend on called service / operation ➢ It may depend on the caller
  29. Asynchronous logging log.info(...) When the ring buffer is full… WAIT!

    Appender MySQL Appender Logstash Appender Hadoop Logger Ring buffer Async Logger Not configurable!
  30. Asynchronous logging log.info(...) When the ring buffer is full… WAIT!

    Appender MySQL Appender Logstash Appender Hadoop Logger Ring buffer Async Logger Async Appender Async Appender Async Appender Not configurable! When async appender full, messages are discarded
  31. Asynchronous operations ❖ Getters ➢ Make them fast (sacrifice consistency)

    ➢ Cache ➢ Use default values ❖ Setters ➢ No operation result ➢ Wait for a notification of operation finished ➢ Query the status of the change
  32. Message queues ❖ Operation queues ➢ Retry system ➢ Persistent

    queues ❖ Publish / subscribe model (pub/sub) ➢ Event driven ➢ Reactive programming
  33. Circuit breaker ❖ From the client, consider the status of

    the service ➢ Previous calls ➢ Health checks ❖ If it’s degraded, don’t call it (close the circuit) ➢ Return a default response ➢ Enqueue the operation for later retry ➢ Throw an error
  34. Many implementations available ❖ Communication layer ➢ gRPC, Cap’n proto,

    Thrift… ➢ REST, JSON… ❖ Services platform ➢ Spring boot, Dropwizard, Spark, Ninja, Jodd… ❖ Netflix stack ➢ Hystrix, Ribbon…