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.
2. Cover w/ Image Agenda • Different systems, new needs • Spring Native • Spring & K8s • Debugging and optimising complex distributed systems
3. Different Systems, New Needs
4. Microservices Serverless Complex Distributed Systems
5. Scalability Resilience Managing a fleet of instances for each service IAAS
6. Quick startup Low memory footprint Instant peak performance
7. Debugging and optimising complex distributed systems
8. Spring Native
9. Based on GraalVM native images
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
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
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
13. Spring Native Image support
14. Native Image Configuration Reflection Proxies Resources
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
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":[] }, ] }
17. Spring Native Configuration @NativeHint(trigger = EnableDiscoveryClientImportSelector. class, types = {@TypeHint(types = {AutoServiceRegistrationConfiguration. class, ConditionalOnReactiveDiscoveryEnabled .class }) }) @ResourceHint() @JdkProxyHint() @SerializationHint () @InitializationHint () @AotProxyHint()
18. Ahead of Time Transformations Spring AOT plugin* * New: 0.11
19. Changes Build time + 2050% Memory -75% Startup time -94% Measurements Source: Sébastien Deleuze, Andy Clement https://www.youtube.com/watch?v=Um9djPTtPe0
20. Changes https://via.vmw.com/native-samples
21. Native Image Configuration Compatibility Optimization Agent support for tests
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
23. Spring Cloud Native Image support Planned support • Spring Cloud Gateway • Spring Cloud OpenFeign • Spring Cloud CircuitBreaker • Spring Cloud Kubernetes
24. DEMO
25. Spring & K8S
26. Spring 🖤 K8s Agenda • Spring Boot & K8S - new and noteworthy • What is Spring Cloud Kubernetes and when to (not) use it
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 ?
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’
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
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/
31. Spring 🖤 K8s The problem • How to store multiple configurations in a single configuration file? • How to store configuration that is platform-specific?
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.
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
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
35. Spring 🖤 K8s The problem • How to ensure that K8s liveness and readiness probing works fine?
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
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
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 "
39. Spring 🖤 K8s Kubernetes probes • You can then configure your Kubernetes infrastructure with the following endpoint information livenessProbe: httpGet: path: /actuator/health/liveness port: <actuator-port> failureThreshold: ... periodSeconds: ... readinessProbe: httpGet: path: /actuator/health/readiness port: <actuator-port> failureThreshold: ... periodSeconds: ...
40. Spring 🖤 K8s The problem • How to create a proper Docker image?
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
42. Spring Cloud & K8S
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
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
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
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
47. Spring Cloud Kubernetes Controllers Roadmap • Service Discovery
48. DOCKER IMAGE BUILDING DEMO
49. Debugging and optimising complex distributed systems
53. What if the apps produced metrics about their state? Is there a way to correlate logs?
54. Let’s Address The Metrics Problem
56. Metrics Store
59. What are metrics good for?
60. What About The Log Correlation?
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
64. Logs Store
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(<generated>) 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(<generated>) 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)
67. What If The System Is Slow?
69. Service 1 Service 3 Service 4 Application Controller Application Service Service 2
70. Service 1 Service 3 Service 4 Application Controller Application Service Service 2 Operation Operation? Operation Operation
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
72. Service 1 Service 3 Service 4 Application Controller Application Service Service 2 Span Span Span Single trace
73. Span Store
74. Span Whole trace Production dependency graph
75. METRICS: Micrometer Spring Boot Actuator
76. TRACING: Spring Cloud Sleuth
77. VMware Tanzu Observability Enterprise observability for multi-cloud environments Free Tanzu Observability for your Spring Boot applications - no sign-up needed
78. presentation-service
79. DEMO
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
81. Thank you @olga_maciaszek @mgrzejszczak © 2020 Spring. A VMware-backed project. 81