Tanzu Tuesday 14 September 2021

Kubernetes has become a de facto standard in the cloud-native software development. Because Spring 🖤 K8s, we have added significant features that make Spring work even better in the Kubernetes environment. The GraalVM project has introduced native images that allow to run Java apps in milliseconds with minimal memory footprint. Because Spring 🖤 native images, we have our own Spring Native project that lets you run Spring Boot apps blazingly fast with low memory consumption. Regardless of how you’re running your applications, production observability is a necessity to debug business problems and latency issues. Because Spring 🖤 observability, we help you add metrics to your processes with Micrometer and visualize latency thanks to distributed tracing with Spring Cloud Sleuth & Tanzu Observability.

In this presentation we will show you how to do all of that with Spring & Spring Cloud.

Transcript

1. Olga Maciaszek-Sharma, Marcin Grzejszczak
   September 2021
   New trends in software
   development with Spring Boot and
   Spring Cloud
   Copyright © 2020 VMware, Inc. or its affiliates.
   

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2. Cover w/ Image
   Agenda
   ● Different systems, new needs
   ● Spring Native
   ● Spring & K8s
   ● Debugging and optimising complex
   distributed systems
   

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3. Different Systems, New Needs
   

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4. Microservices
   Serverless
   Complex Distributed Systems
   

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5. Scalability
   Resilience
   Managing a fleet of instances
   for each service
   IAAS
   

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6. Quick startup
   Low memory footprint
   Instant peak performance
   

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7. Debugging and optimising
   complex distributed systems
   

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8. Spring Native
   

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9. Based on GraalVM native
   images
   

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10. GraalVM
    A high-performance polyglot runtime
    ● 1 VM for all languages
    ● Increased efficiency (memory, CPU, resources)
    ● JIT && AOT
    Source: @thomaswue https://twitter.com/thomaswue/status/1145603781108928513?s=20
    

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11. Graal VM Native Images / AOT
    Application
    Libraries
    JDK
    Substrate VM
    Analysis
    Initializations
    Heap snapshotting
    Native
    Executable
    (pre-loaded classes,
    pre-loaded config)
    Reachable byte code Machine code
    Build phase: compilation, class-loading, pre-loading configuration
    Closed World Assumption - no classes being loaded at runtime
    

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12. GraalVM Native Images
    PROs
    ● Instant startup
    ● No JIT -> reduced memory footprint
    ● Instant peak performance
    ● Sustainable
    CONs
    ● Peak throughput and max latency (although optimizations available)
    ● Build time
    

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13. Spring Native Image support
    

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14. Native Image Configuration
    Reflection
    Proxies
    Resources
    

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15. Native Image Configuration
    META-INF/native-image/resource-config.json
    META-INF/native-image/reflect-config.json
    META-INF/native-image/proxy-config.json
    

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16. Spring Native Configuration
    java
    -agentlib:native-image-agent=config-output-dir=src/main/resources/M
    ETA-INF/native-image -jar target/appname-0.0.1-SNAPSHOT.jar
    {
    "name":"org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinde
    rAutoConfiguration",
    "allDeclaredFields":true,
    "allDeclaredMethods":true,
    "allDeclaredConstructors":true,
    "methods":[
    {"name":"afterSingletonsInstantiated","parameterTypes":[] },
    ]
    }
    

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17. Spring Native Configuration
    @NativeHint(trigger = EnableDiscoveryClientImportSelector.
    class,
    types = {@TypeHint(types = {AutoServiceRegistrationConfiguration.
    class,
    ConditionalOnReactiveDiscoveryEnabled
    .class })
    })
    @ResourceHint()
    @JdkProxyHint()
    @SerializationHint
    ()
    @InitializationHint
    ()
    @AotProxyHint()
    

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18. Ahead of Time
    Transformations
    Spring AOT plugin*
    * New: 0.11
    

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19. Changes
    Build time + 2050%
    Memory -75%
    Startup time -94%
    Measurements Source: Sébastien Deleuze, Andy Clement https://www.youtube.com/watch?v=Um9djPTtPe0
    

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20. Changes
    https://via.vmw.com/native-samples
    

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21. Native Image Configuration
    Compatibility
    Optimization
    Agent support for tests
    

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22. Spring Cloud Native Image support
    Supported starters
    ● Spring Cloud Config Client
    ● Spring Cloud Config Server
    ● Spring Cloud LoadBalancer
    ● Spring Cloud Netflix Eureka Client
    ● Spring Cloud Sleuth
    ● Spring Cloud Function
    ● Spring Cloud Stream
    ● Spring Cloud Task
    ● Spring Cloud Sleuth Zipkin
    

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23. Spring Cloud Native Image support
    Planned support
    ● Spring Cloud Gateway
    ● Spring Cloud OpenFeign
    ● Spring Cloud CircuitBreaker
    ● Spring Cloud Kubernetes
    

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24. DEMO
    

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25. Spring & K8S
    

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26. Spring 🖤 K8s
    Agenda
    ● Spring Boot & K8S - new and noteworthy
    ● What is Spring Cloud Kubernetes and when to (not) use it
    

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27. Spring 🖤 K8s
    The problem
    ● Need to read config values that the platform supplies?
    ● Let’s inject them via environment variables!
    ○ What if the value is supposed to be kept secret ?
    

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28. Spring 🖤 K8s
    The solution
    ● Many cloud platforms now allow you to map configuration into mounted data volumes
    ○ For example, Kubernetes can volume mount both ConfigMaps and Secrets
    ● Two common volume mount patterns that can be used:
    ○ A single file contains a complete set of properties (usually written as YAML)
    ○ Multiple files are written to a directory tree
    ■ Filename becoming the ‘key’
    ■ Contents becoming the ‘value’
    

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29. Spring 🖤 K8s
    A single file contains a complete set of properties
    ● Import the YAML or Properties file directly using spring.config.import
    spring.config.import=/location/to/your/config/my.properties
    

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30. Spring 🖤 K8s
    Multiple files are written to a directory tree
    ● Use the configtree: prefix to expose all the files as properties
    ● Let’s assume the following Kubernetes configuration tree
    etc/
    config/
    myapp/
    username
    password
    ● Pass the following properties to load those entries
    spring.config.import=optional:configtree:/etc/config/
    

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31. Spring 🖤 K8s
    The problem
    ● How to store multiple configurations in a single configuration file?
    ● How to store configuration that is platform-specific?
    

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32. Spring 🖤 K8s
    The solution
    ● Spring Boot allows you to split a single physical file into multiple logical documents
    ● Documents are processed in order, from top to bottom.
    ○ Later documents can override the properties defined in earlier ones.
    

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33. Spring 🖤 K8s
    The solution - YAML
    ● For application.yml files, the standard YAML multi-document syntax is used.
    Three consecutive hyphens represent the end of one document, and the start of the
    next.
    spring.application.name: MyApp
    ---
    spring.config.activate.on-cloud-platform: kubernetes
    spring.application.name: MyCloudApp
    

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34. Spring 🖤 K8s
    The solution - properties
    ● For application.properties files a special #--- comment is used to mark the
    document splits:
    spring.application.name=MyApp
    #---
    spring.config.activate.on-cloud-platform=kubernetes
    spring.application.name=MyCloudApp
    

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35. Spring 🖤 K8s
    The problem
    ● How to ensure that K8s liveness and readiness probing works fine?
    

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36. Spring 🖤 K8s
    Liveness
    ● “Liveness” state
    ○ Internal state allows it to work correctly?
    ○ Can recover by itself if it’s currently failing?
    ● A broken “Liveness”
    ○ Cannot recover from, and the infrastructure should restart the application
    ● "Liveness" state should not be based on external checks, such as Health checks
    ○ A failing external system (a database, a Web API, an external cache) would
    trigger massive restarts and cascading failures across the platform
    

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37. Spring 🖤 K8s
    Readiness
    ● The application is ready to handle traffic.
    ● A failing “Readiness” state
    ○ Tells the platform that it should not route traffic to the application for now.
    Typically happens
    ■ During startup, while CommandLineRunner and ApplicationRunner
    components are being processed
    ■ At any time if the application decides that it’s too busy for additional traffic
    ● An application is considered ready as soon as application and command-line
    runners have been called
    

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38. Spring 🖤 K8s
    Kubernetes probes
    ● Spring Boot manages your Application Availability State out-of-the-box
    ● If deployed in a Kubernetes environment, actuator will gather the "Liveness" and
    "Readiness" information in dedicated Liveness and Readiness Health Indicators
    ● These indicators will be shown on the global health endpoint
    ("/actuator/health" )
    ● They will also be exposed as separate HTTP Probes using Health Groups:
    "/actuator/health/liveness " and "/actuator/health/readiness "
    

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39. Spring 🖤 K8s
    Kubernetes probes
    ● You can then configure your Kubernetes infrastructure with the following endpoint
    information
    livenessProbe:
    httpGet:
    path: /actuator/health/liveness
    port:
    failureThreshold: ...
    periodSeconds: ...
    readinessProbe:
    httpGet:
    path: /actuator/health/readiness
    port:
    failureThreshold: ...
    periodSeconds: ...
    

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40. Spring 🖤 K8s
    The problem
    ● How to create a proper Docker image?
    

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41. Spring 🖤 K8s
    The solution - buildpacks
    ● Transform your application source code to images that can run on any cloud
    ○ Paketo Buildpacks provide language runtime support for applications
    ■ They leverage the Cloud Native Buildpacks framework to make image
    builds easy, performant, and secure
    

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42. Spring Cloud & K8S
    

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43. Spring Cloud & K8s
    Kubernetes
    → Cloud Native patterns handled on platform level
    Spring Cloud
    → Cloud Native patterns handled on application level
    Spring Cloud Kubernetes
    → Integrating Spring Cloud apps with Kubernetes components
    

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44. Spring Cloud & K8s
    Do you need Spring Cloud Kubernetes to use Kubernetes with
    Spring?
    → No
    When is Spring Boot directly with K8s most useful?
    ● Creating new applications from scratch
    ● Running your entire microservice ecosystem on Kubernetes
    

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45. Spring Cloud & K8s
    When is Spring Cloud Kubernetes most useful?
    ● Migrating existing Spring Cloud - based applications to K8s
    ● Running applications across multiple cloud platforms
    ● More transparency and configuration options for load-balancing from developer’s
    point of view
    ● Implementing Kubernetes controllers in Java
    Downside:
    ● Uses Kubernetes API Server - apps need permissions to interact with it
    

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46. Spring Cloud Kubernetes Controllers
    Spring Cloud Configuration Watcher
    ● Configuration refresh support for K8S ConfigMap/ Secret volumes
    ● HTTP /refresh actuator endpoint support
    ● Spring Cloud Bus support (with messaging)
    https://via.vmw.com/config-watcher https://via.vmw.com/config-watcher-docs
    

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47. Spring Cloud Kubernetes Controllers
    Roadmap
    ● Service Discovery
    

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48. DOCKER IMAGE
    BUILDING DEMO
    

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49. Debugging and optimising
    complex distributed systems
    

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53. What if the apps
    produced metrics
    about their state?
    Is there a way to
    correlate logs?
    

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54. Let’s Address The Metrics
    Problem
    

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56. Metrics
    Store
    

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59. What are metrics good for?
    

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60. What About The Log
    Correlation?
    

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61. TraceId: 123
    2021-02-10 13:57:55.239 … HELLO FROM SERVICE1
    123
    123
    2021-02-10 13:58:10.239 … HELLO FROM SERVICE2
    123 123
    123
    2021-02-10 13:58:20.239 … HELLO FROM SERVICE4
    123
    2021-02-10 13:58:30.239 … HELLO FROM SERVICE3
    123
    

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64. Logs
    Store
    

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65. [6dad9c7bd47f0e21c946a7a57d75e7c8] 2021-02-10 13:57:55.239 ERROR 274441 --- [nio-8082-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet] :
    Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is
    java.lang.IllegalStateException: Meme overflow occurred] with root cause
    java.lang.IllegalStateException: Meme overflow occurred
    at io.memegenerator.MemeController.generateMeme(Application.java:93)
    at io.memegenerator.MemeController$$FastClassBySpringCGLIB$$d54a9db6.invoke()
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:771)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:97)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749)
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:691)
    at io.memegenerator.MemeController$$EnhancerBySpringCGLIB$$e33f7fa1.memeOverflow()
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:567)
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:197)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:141)
    at
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1061)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:961)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:626)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:733)
    

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67. What If The System Is Slow?
    

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69. Service 1
    Service 3
    Service 4
    Application
    Controller
    Application
    Service
    Service 2
    

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70. Service 1
    Service 3
    Service 4
    Application
    Controller
    Application
    Service
    Service 2
    Operation Operation?
    Operation
    Operation
    

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71. TraceId:123
    T:123
    T:123
    T:123
    S:234
    S:456
    S:345
    SpanId:123
    - Parent ID
    - Start time
    - Stop time
    - Duration
    - Meta-data
    SpanId: 456
    

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72. Service 1
    Service 3
    Service 4
    Application
    Controller
    Application
    Service
    Service 2
    Span
    Span
    Span
    Single trace
    

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73. Span
    Store
    

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74. Span
    Whole trace
    Production dependency graph
    

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75. METRICS:
    Micrometer
    Spring Boot Actuator
    

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76. TRACING:
    Spring Cloud Sleuth
    

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77. VMware Tanzu Observability
    Enterprise observability for multi-cloud
    environments
    Free Tanzu Observability for your Spring Boot applications - no
    sign-up needed
    

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78. presentation-service
    

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79. DEMO
    

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80. Helpful Resources
    ● Presentation demo code
    ● The Path Towards Spring Boot Native Applications
    ● Announcing Spring Native Beta!
    ● Spring Native presentation from Spring One 2021
    ● Spring on Kubernetes! Workshop
    ● Spring On Kubernetes with Ryan Baxter
    ● Spring On Kubernetes Topical Guide
    ● WIP: Kubernetes Discovery Controller
    

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81. Thank you
    @olga_maciaszek
    @mgrzejszczak
    © 2020 Spring. A VMware-backed project. 81
    

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