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Keda External Scaler with ActiveMQ Artemis
This sample has been updated to use KEDA v2 and ActiveMQ Artemis 2.15.0
This is a demonstration on how to use KEDA's external scaler to monitor ActiveMQ Artemis Queue.
The Keda external scaler calls metrics-provider GRPC server which will collect the metrics from ActiveMQ Artemis.
ActiveMQ Artemis is now included as part of the KEDA internal scaler
Note: use your own docker repository while building the project.
Pre-requisites:
- Kubernetes cluster
- Keda installed in the cluster.
- skaffold - used to build the images
- maven - use to build the java consumer and producer project.
Code organization
- consumer - a simple Springboot application which consumes messages from ActiveMQ Artemis. The queue name used is
test
. TheconsumerWindowSize
is also set to0
so that it will not buffer the messages to one consumer. - producer - a simple Springboot application which pumps messages to the queue
test
- metrics-provider - a Go application which serves as the GRPC server to serve the Keda External Scaler. It queries ActiveMQ Artemis
MessageCount
using the built -in jolokia endpoint exposed by Artemis. - k8s-manifest - everything Kubernetes
Building the metrics provider for external scaler
You can get the proto
file from the Keda github.
This project already contains the externalscaler.proto
Use protoc to autogenerate the Proto codes.
protoc -I externalscaler/ externalscaler/proto/externalscaler.proto --go_out=plugins=grpc:externalscaler
Note: We use kaniko in-cluster builder
Setup kaniko registry access secret
kubectl -n artemis create secret generic regcred --from-file $HOME/.docker/config.json
$ skaffold run -p metrics-provider
External Scaler as ActiveMQ Artemis sidecar
The docker image used taken from vromero/activemq-artemis-docker uses the hostname
as its broker name, in order to avoid hardcoding the broker name, the metrics provider is deployed as a sidecar to ActiveMQ Artemis.
Added to the file k8s-manifest/artemis/deployment.yaml
containers:
- name: artemis-activemq-metrics-provider
image: docker.io/balchu/artemis-ext-scaler:1.0.0
args: ["--port","5050","--broker","$(POD_NAME)", "--user", "$(ARTEMIS_USERNAME)","--password","${ARTEMIS_PASSWOORD)"]
imagePullPolicy: Always
resources:
requests:
cpu: 100m
memory: 10Mi
Build and deploy the consumer.
Using skaffold and jib, simply execute the command below.
skaffold run -p consumer
Please make sure that you use your docker repository.
Deploy the External Scaler manifest
Now its time to setup the KEDA's external scaler.
kubectl apply -f k8s-manifest/externalscaler_scaledobject.yaml
The file looks like this.
apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
name: artemis-scaledobject
namespace: artemis
spec:
pollingInterval: 5 # Optional. Default: 30 seconds
cooldownPeriod: 5 # Optional. Default: 300 seconds
minReplicaCount: 0 # Optional. Default: 0
maxReplicaCount: 30 # Optional. Default: 100
scaleTargetRef:
name: artemis-consumer
triggers:
- type: external
metadata:
scalerAddress: artemis-activemq.artemis:5050
queueLength: "10"
brokerAddress: "test"
queueName: "test"
Where:
scalerAddress
: is the location of the GRPC metrics provider host and port.queueLength
: the target queue length.brokerAddress
: An address represents a messaging endpoint. Within the configuration, a typical address is given a unique name, 0 or more queues, and a routing type.queueName
: the name of queue to monitor.
Before pumping in messages, check the HPA.
Check the HPA
kubectl -n artemis get hpa
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
keda-hpa-artemis-consumer Deployment/artemis-consumer <unknown>/20 (avg) 1 30 0 58m
At this point,HPA doesn't have the TargetAverageValue
to scale up or down the pods. This can be observed by the <unknown>/20(avg)
Start the producer
The producer is a simple Springboot application.
If you are going to run the Springboot application using your IDE, make sure that you point to the host and port of the ActiveMQ Artemis.
Check the file application.yml
As an example:
spring:
artemis:
mode: native
host: ${ARTEMIS_SERVER_HOST:10.152.183.227}
port: ${ARTEMIS_SERVER_PORT:61616}
user: ${ARTEMIS_USERNAME:artemis}
password: ${ARTEMIS_PASSWORD:artemis}
In the Class App.java
You can modify how much messages you want to send to the broker. In the example below, the program is pushing 10000 messages to the broker, with a delay of 200 milliseonds.
public void run(String... args) throws Exception {
for (int i = 0; i < 10000; i++){
producer.send("Message is: " + System.currentTimeMillis());
sleep(200);
}
}
Checking the scaling up of the pods.
$ kubectl -n artemis get pods
NAME READY STATUS RESTARTS AGE
artemis-activemq-66c66ffdcc-9f7hq 2/2 Running 0 15m
artemis-consumer-589c9b87f7-mldrx 0/1 ContainerCreating 0 4s
artemis-consumer-589c9b87f7-mltqx 1/1 Running 0 14s
Scale to zero
Once you stop the producer program, KEDA will determine that messages are no longer coming and will scale down the pods to zero.
$kubectl -n artemis get pods -w
NAME READY STATUS RESTARTS AGE
artemis-activemq-66c66ffdcc-9f7hq 2/2 Running 0 16m
artemis-consumer-589c9b87f7-8xwq6 1/1 Running 0 43s
artemis-consumer-589c9b87f7-k2bf5 1/1 Running 0 12s
artemis-consumer-589c9b87f7-mldrx 1/1 Running 0 58s
artemis-consumer-589c9b87f7-mltqx 1/1 Running 0 68s
artemis-consumer-589c9b87f7-mltqx 1/1 Terminating 0 81s
artemis-consumer-589c9b87f7-8xwq6 1/1 Terminating 0 56s
artemis-consumer-589c9b87f7-mldrx 1/1 Terminating 0 71s
artemis-consumer-589c9b87f7-k2bf5 1/1 Terminating 0 25s
artemis-consumer-589c9b87f7-8xwq6 0/1 Terminating 0 57s
artemis-consumer-589c9b87f7-mldrx 0/1 Terminating 0 72s
artemis-consumer-589c9b87f7-k2bf5 0/1 Terminating 0 27s
artemis-consumer-589c9b87f7-mldrx 0/1 Terminating 0 73s
artemis-consumer-589c9b87f7-mldrx 0/1 Terminating 0 73s
artemis-consumer-589c9b87f7-mltqx 0/1 Terminating 0 83s
Clean up
Delete the consumer
skaffold delete -p consumer
Delete ActiveMQ Artemis and the metrics provider
skaffold delete -p metrics-provider
Delete the External Scaler object
kubectl delete -f k8s-manifest/externalscaler_scaledobject.yaml
Verify that the HPA is successfully deleted
kubectl -n artemis get hpa