springboot with cluster of brokers

[lnthai2002]

Hello,
I am running a single broker but now i am trying to scale up to a cluster of 2 brokers with the following config:

apiVersion: broker.amq.io/v1beta1
kind: ActiveMQArtemis
metadata:
name: activemq-artemis-broker
spec:
acceptors:
- name: "scaleDown"
bindToAllInterfaces: true
port: 61616
protocols: "CORE"
addressSettings:
applyRule: merge_all
addressSetting:
- match: '#'
deadLetterAddress: DLQ
expiryAddress: ExpiryQueue
redistributionDelay: 60000
redeliveryDelay: 0
maxSizeBytes: "-1"
messageCounterHistoryDayLimit: 10
addressFullPolicy: PAGE
autoCreateQueues: true
autoCreateAddresses: true
autoCreateJmsQueues: true
autoCreateJmsTopics: true
autoDeleteQueues: false
autoDeleteCreatedQueues: false
autoDeleteAddresses: false
defaultConsumerWindowSize: 0
console:
expose: true
sslEnabled: false
deploymentPlan:
size: 2
requireLogin: true
messageMigration: true
persistenceEnabled: true
podSecurityContext:
fsGroup: 0
storage:
size: {{ .Values.persistence.size }}
storageClassName: {{ .Values.persistence.storageClass }}
resources:
requests:
cpu: {{ .Values.resources.requests.cpu }}
memory: {{ .Values.resources.requests.memory }}
adminUser: {{ .Values.artemisUser }}
adminPassword: {{ .Values.artemisPassword }}

I can see 2 broker pods but only 1 services to port 61616:
activemq-artemis-broker-hdls-svc ClusterIP None 8161/TCP,61616/TCP 13d

My application is a spring boot 3 app with spring-boot-starter-artemis dependency so my application.properties has this when i am running a single broker:
spring.artemis.broker-url=tcp://activemq-artemis-broker-hdls-svc.mynamespace.svc.cluster.local:61616?clientFailureCheckPeriod=30000
However, now that i have a cluster of 2 brokers, do i need to add a 2nd service to the broker-url string so that when a broker goes down, the client can connect to the other broker (i enabled messageMigration above)?

Also, is there a way to change the name of the kubernetes services from activemq-artemis-broker-hdls-svc to something like "artemis-core-svc"? Asking because I have another standalone broker (not deployed by operator) running and it already has that service name so when i switch to operator i want to keep all the client unchanged.

[brusdev]

The operator automatically creates a service for each broker acceptors and you could use those services to build the url of your spring boot app.
In your case the operator is not creating the acceptor services because your accewptor name includes an uppercase character:

ERROR package k8s_actions Failed to create new *v1.Service {"ActiveMQArtemis Name": "artemis-broker-scaleDown-0-svc", "Namespace": "default", "error": "Service \"artemis-broker-scaleDown-0-svc\" is invalid: [metadata.name: Invalid value: \"artemis-broker-scaleDown-0-svc\": a DNS-1035 label must consist of lower case alphanumeric characters or '-', start with an alphabetic character, and end with an alphanumeric character (e.g. 'my-name',  or 'abc-123', regex used for validation is '[a-z]([-a-z0-9]*[a-z0-9])?'), spec.ports[0].name: Invalid value: \"scaleDown-0\": a lowercase RFC 1123 label must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character (e.g. 'my-name',  or '123-abc', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?')]"}

Changing the acceptor name will fix this issue but I would recommend to use another acceptor port because 61616 is used also for internal purposes.

The operator creates acceptor name using the following pattern the <CR_NAME>-<ACCEPTOR_NAME>-<SS_INDEX>-svc you could create another service if you need a custom name or create an issue to request this new feature.

[lnthai2002]

Thank you. I removed the acceptors block from the config so that it is similar to the example https://artemiscloud.io/docs/tutorials/scaleup_and_scaledown/ and when i looked at the broker.xml in the broker pod i see:
<acceptor name="scaleDown">tcp://activemq-artemis-broker-ss-0.activemq-artemis-broker-hdls-svc.ncp-stack-testing12.svc.cluster.local:61616?protocols=CORE;tcpSendBufferSize=1048576;tcpReceiveBufferSize=1048576;useEpoll=true;amqpCredits=1000;amqpMinCredits=300</acceptor>
so I assume this is the default connector.
However, i still see only 1 kubernetes service that expose port 61616 but 2 services for web console:
root@rdadmin-Virtual-Machine:/home/rdadmin# kubectl get service -n ncp-stack-testing12 NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE activemq-artemis-broker-hdls-svc ClusterIP None <none> 8161/TCP,61616/TCP 21m activemq-artemis-broker-ping-svc ClusterIP None <none> 8888/TCP 21m activemq-artemis-broker-wconsj-0-svc ClusterIP 172.20.101.81 <none> 8161/TCP,8162/TCP 21m activemq-artemis-broker-wconsj-1-svc ClusterIP 172.20.42.7 <none> 8161/TCP,8162/TCP 4m36s

My question is more about how to config springboot client to use clusted of broker, do i need to specify all services for all broker or just the single service activemq-artemis-broker-hdls-svc that look like a load balancer for all the brokers in the cluster?

[brusdev]

The operator automatically creates a service for each broker acceptors and you could use those services to build the url of your spring boot app, i.e. the operator will create 2 services for the core-acceptor, one for each broker instance defined in the following CR:

apiVersion: broker.amq.io/v1beta1
kind: ActiveMQArtemis
metadata:
  name: artemis-broker
spec:
  deploymentPlan:
    size: 2
  acceptors:
    - name: "core-acceptor"
      port: 61617
      protocols: "CORE"

$ kubectl get service
NAME                                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)              AGE
artemis-broker-core-acceptor-0-svc   ClusterIP   10.99.251.174   <none>        61617/TCP            3m
artemis-broker-core-acceptor-1-svc   ClusterIP   10.111.165.7    <none>        61617/TCP            2m34s

The spring boot app could use the following broker url to distribuite client across 2 broker instances and get reconnect after a temporary issue:

spring.artemis.broker-url=(tcp://artemis-broker-core-acceptor-0-svc.mynamespace.svc.cluster.local:61617,tcp://artemis-broker-core-acceptor-1-svc.mynamespace.svc.cluster.local:61617)?reconnectAttempts=-1

[lnthai2002]

thank you

[lnthai2002]

Hello, is there a way to scale up the number of broker without changing the connection string on the client side?

[brusdev]

@lnthai2002 you could manually create a ClusterIP service, i.e.:

apiVersion: broker.amq.io/v1beta1
kind: ActiveMQArtemis
metadata:
  name: artemis-broker
spec:
  deploymentPlan:
    size: 2
  acceptors:
    - name: "core-acceptor"
      port: 61617
      protocols: "CORE"

oc create -f - <<EOF
apiVersion: v1
kind: Service
metadata:
  name: artemis-broker-svc
spec:
  ports:
  - port: 61617
    protocol: TCP
  selector:
    ActiveMQArtemis: artemis-broker
    application: artemis-broker-app
  type: ClusterIP
status:
  loadBalancer: {}
EOF

spring.artemis.broker-url=tcp://artemis-broker-svc.mynamespace.svc.cluster.local:61617?reconnectAttempts=-1