Coherence

Component format

To setup Coherence state store, create a component of type state.coherence. See this guide on how to create and apply a state store configuration.

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: <NAME>
spec:
  type: state.coherence
  version: v1
  metadata:
  - name: serverAddress
    value: <REPLACE-WITH-GRPC-PROXY-HOST-AND-PORT> # Required. Example: "my-cluster-grpc:1408"
  - name: tlsEnabled
    value: <REPLACE-WITH-BOOLEAN> # Optional
  - name: tlsClientCertPath
    value: <REPLACE-WITH-PATH> # Optional
  - name: tlsClientKey
    value: <REPLACE-WITH-PATH> # Optional
  - name: tlsCertsPath
    value: <REPLACE-WITH-PATH> # Optional
  - name: ignoreInvalidCerts
    value: <REPLACE-WITH-BOOLEAN> # Optional
  - name: scopeName
    value: <REPLACE-WITH-SCOPE> # Optional
  - name: requestTimeout
    value: <REPLACE-WITH-REQUEST-TIMEOUT> # Optional
  - name: nearCacheTTL
    value: <REPLACE-WITH-NEAR-CACHE-TTL> # Optional
  - name: nearCacheUnits
    value: <REPLACE-WITH-NEAR-CACHE-UNITS> # Optional
  - name: nearCacheMemory
    value: <REPLACE-WITH-NEAR-CACHE-MEMORY> # Optional

Spec metadata fields

About Using Near Cache TTL

The Coherence state store allows you to specify a near cache to cache frequently accessed data when using the DAPR client. When you access data using Get(ctx context.Context, req *GetRequest), returned entries are stored in the near cache and subsequent data access for keys in the near cache is almost instant, where without a near cache each Get() operation results in a network call.

When using the near cache option, Coherence automatically adds a MapListener to the internal cache which listens on all cache events and updates or invalidates entries in the near cache that have been changed or removed on the server.

To manage the amount of memory used by the near cache, the following options are supported when creating one:

• nearCacheTTL – objects expired after time in near cache, for example 5 minutes
• nearCacheUnits – maximum number of cache entries in the near cache
• nearCacheMemory – maximum amount of memory used by cache entries

You can specify either High-Units or Memory and in either case, optionally, a TTL.

The minimum expiry time for a near cache entry is 1/4 second. This is to ensure that expiry of elements is as efficient as possible. You will receive an error if you try to set the TTL to a lower value.

Setup Coherence

• Self-Hosted
• Kubernetes

docker run -d -p 1408:1408 -p 30000:30000 ghcr.io/oracle/coherence-ce:25.03.1

kubectl apply -f https://github.com/oracle/coherence-operator/releases/download/v3.5.2/coherence-operator.yaml

apiVersion: coherence.oracle.com/v1
kind: Coherence
metadata:
  name: my-cluster
spec:
  coherence:
    management:
      enabled: true
  ports:
    - name: management
    - name: grpc
      port: 1408

kubectl apply -f my-cluster.yaml

NAME                    TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)                                               AGE
kubernetes              ClusterIP   10.96.0.1      <none>        443/TCP                                               9m
my-cluster-grpc         ClusterIP   10.96.225.43   <none>        1408/TCP                                              7m3s
my-cluster-management   ClusterIP   10.96.41.6     <none>        30000/TCP                                             7m3s
my-cluster-sts          ClusterIP   None           <none>        7/TCP,7575/TCP,7574/TCP,6676/TCP,30000/TCP,1408/TCP   7m3s
my-cluster-wka          ClusterIP   None           <none>        7/TCP,7575/TCP,7574/TCP,6676/TCP                      7m3s

Related links

• Basic schema for a Dapr component
• Read this guide for instructions on configuring state store components
• State management building block
• Coherence CE on GitHub
• Coherence Community - All things Coherence