As Monolith to Microservices migration almost became mainstream, Engineering Teams have to think about how their caching strategies will evolve in cloud-native world. Kubernetes is clear winner in containerized world so caching solutions must be cloud-ready and natural fit for Kubernetes. Caching is an important piece in high performance microservices and choosing right architectural pattern can be crucial for your deployments. Hazelcast is a well known caching solution in open source community and can handle caching piece in microservices based applications. In this talk, you will learn * Distributed Caching With Hazelcast * Distributed Caching Patterns in Kubernetes * Kubernetes Deployment Options and Best Practices * How to Handle Distributed Caching Day 2 Operations

1. @mesutcelik
Distributed Caching Patterns
in Kubernetes
Mesut Celik,Hazelcast

2. @mesutcelik
Mesut Celik
● Tech Lead @Hazelcast
● Java Developer
● lived in Turkey,Belgium,US
● Twitter: @mesutcelik

3. @mesutcelik
Agenda
● Hazelcast Introduction
● Caching Patterns
● Kubernetes Deployments
● Day 2 Operations

4. @mesutcelik
Hazelcast Products
● Hazelcast IMDG
● Hazelcast Jet
● Hazelcast Cloud
● Management Center
Hazelcast is an Open Source
Company
● Apache 2 License
● Remote friendly
● raised $21M series C
● Always hiring!!!!

5. @mesutcelik
Why Distributed Cache?
● Cache, Memory is faster than storage
● Distributed,Natural fit for Cloud-Native Deployments

6. @mesutcelik
Cache Layers

7. @mesutcelik
Caching Patterns

8. @mesutcelik
Cache-aside
Application
DB
Cache
Application
DB
Cache
Read-through, Write-through, Write-behind
Caching Patterns
Cache-as-SoR

9. @mesutcelik
Read-Through Cache

10. @mesutcelik
Read-Through Cache 1,MinskPartition_34
1,MinskBackup_34

11. @mesutcelik
Hazelcast and Kubernetes
Caching Patterns

12. @mesutcelik
Distributed Caching Patterns in Kubernetes
● Embedded
● Sidecar
● Proxy Cache
● Client-Server

13. @mesutcelik
POD
Spring Boot Microservice
Hazelcast
Member
POD
Hazelcast ClusterKubernetesService
Http Request
Embedded
Spring Boot Microservice
Hazelcast
Member
Kubernetes Cluster

14. @mesutcelik
Embedded
● Simple
● Java only
● Data co-located with Microservice JVM

15. @mesutcelik
Python
Microservice
POD
Hazelcast
Member
Python
Microservice
POD
Hazelcast
Member
Hazelcast ClusterKubernetesService
Http Request
SideCar Kubernetes Cluster
hazelcast-client
hazelcast-client

16. @mesutcelik
Sidecar
● Simple
● Multiple Programming Languages
○ Java, Node.js, .NET, Python, Golang
● Data co-located with Microservice POD

17. hazelcast-proxy
sidecar
POD
Spring Boot
Application
POD
Spring Boot
Application
Hazelcast ClusterKubernetesService
Http Request
Http reverse
proxy caching
Hazelcast
Member
hazelcast-proxy
sidecar
Hazelcast
Member
Kubernetes Cluster

18. Http reverse proxy caching
● Injecting Cache into every microservice
● No coupling with any Cache API
● Enabled w/o code change

19. @mesutcelik
POD
Spring Boot Microservice
hazelcast-java-client
Hazelcast ClusterKubernetesService
Http Request
Client Server
POD
Hazelcast
Member
POD
Hazelcast
Member
Kubernetes Cluster
POD
Spring Boot Microservice
hazelcast-java-client
POD
ASP.NET Core
Microservice
hazelcast-dotnet-client
KubernetesService
Http Request

20. @mesutcelik
POD
KubernetesService
Http Request
Hazelcast Cloud
POD
cloud.hazelcast.com
Hazelcast Cluster
Kubernetes Cluster
Spring Boot
Application
hazelcast-client
Spring Boot
Application
hazelcast-client

21. @mesutcelik
Client Server
● CaaS - Cache as a Service
● Multiple Programming Languages
○ Java, nodejs, .NET, Python, Golang
● Separate Microservice and Hazelcast Layers

22. @mesutcelik
Spring Boot - Hazelcast Embedded Config
@Bean
public Config hazelcastConfig() {
Config config = new Config();
JoinConfig joinConfig = config.getNetworkConfig().getJoin();
joinConfig.getMulticastConfig().setEnabled(false);
joinConfig.getKubernetesConfig().setEnabled(true);
return config;
}

23. @mesutcelik
Spring Boot - Hazelcast Client Config
@Bean
public ClientConfig hazelcastConfig() {
ClientConfig config = new ClientConfig();
config.getNetworkConfig().getKubernetesConfig().setEnabled(true);
return config;
}

24. @mesutcelik
Hazelcast Cache Put and Get Operations
@Autowired
HazelcastInstance hazelcast;
Map<String, String> cities = hazelcast.getMap("cities");
cities.put("1","Minsk");
System.out.println("Best City in the world is " + cities.get("1"));

25. @mesutcelik
Kubernetes Deployment Options
For Hazelcast

26. @mesutcelik
Hazelcast Helm Chart
$ helm install stable/hazelcast

27. @mesutcelik
Hazelcast Kubernetes Operator
● OperatorHub.io
● Openshift 4 Operator Catalog
● IBM Cloud Private

28. @mesutcelik
Hazelcast Cloud
● Managed Service
● Pay as you go model
● https://cloud.hazelcast.com

29. @mesutcelik
Deployment Best Practices

30. @mesutcelik
Predictable Resource Allocation
● Calculate CPU/Memory Requirements
● Set Resource Request and Limits as the same value

31. @mesutcelik
Pod Anti-Affinity
● Hazelcast per K8S Node
● Large Kubernetes Clusters
● Safer in Node crushes

32. @mesutcelik
Multi-zone Deployment with ZONE_AWARE
hazelcast-member -1
hazelcast-member -2
hazelcast-member -3
Availability-Zone-A
hazelcast-member -4
hazelcast-member -5
hazelcast-member -6
Availability-Zone-B
Multi-zone Hazelcast Cluster
* Multi-zone if your architecture prefers availability over performance

33. @mesutcelik
Day 2 Operations

34. @mesutcelik
Scaling Hazelcast Cluster
● Manual Scaling (kubectl scale or helm upgrade)
● Horizontal Pod Autoscaler (HPA)
● Vertical Pod Autoscaler
● Cluster Autoscaler

35. @mesutcelik
Rolling Upgrade - Why?
● Hazelcast Version Update
● Config Change
● Adding Jar to the classpath

36. @mesutcelik
Rolling Upgrade - How?
● helm upgrade (--set image.tag)
● kubectl set image
● StatefulSet
● Deployment with RollingUpdateStrategy
● Enable Graceful Shutdown
● Optimized Grace Period

37. @mesutcelik
Monitoring
● Hazelcast Management Center
● Metrics via Prometheus
● Alerting

38. @mesutcelik
Thank you!
● https://twitter.com/mesutcelik
● https://github.com/mesutcelik
● https://www.linkedin.com/in/mesutcelik/