caronte

Caronte has been created to provide swarm services horizontal based threshold for metrics.

Features

• Configuration automatically
• Supports multiple infrastructure providers (current only AWS)
• Support multiple metrics stores providers (cloudWatch, prometheus)
• Scale rules defined by services

Configuration

command	Description
log.level	Set log level. Default value INFO. Allowed DEBUG and INFO
dashboard	Activate Caronte dashboard
dashboard.port	Define Caronte dashboard port. Default value 80
service.scheduler.discovery.time	Define service discovery timer in seconds
sqs.metic.publisher.queue.name	Activate AWS SQS metrcis
sqs.metic.publisher.queue.time	Define AWS SQS metrics time

Service Configuration labels

Level	Scope	Description
caronte.scale.max	Service	Define the max replicas for a target service
caronte.scale.min	Service	Define the min replicas for a target service
caronte.scale.step	Service	Define the step replicas increase for a target service
caronte.scale.service.coolDownDelay	Service	Define coolDown time in seconds for services scale
caronte.scale.maxPreplicasPerNode	Service	Define max replicas per node when the instance provider is activated
caronte.metric.store	Metrics	Metric store to be used allowed (cloudwatch , prometheus)
caronte.metric.query	Metrics	Metric store query
caronte.metric.scaleUpThreshold	Metrics	Scale up metric Threshold
caronte.metric.scaleDownThreshold	Metrics	Scale down metric Threshold
caronte.metric.prometheus.address	Metrics/Prometheus	Prometheus server address
caronte.metric.aws.period	Metrics/AWS	CloudWatch query period in seconds
caronte.instance.provider	Instances	Instances provider allowed (aws)
caronte.instance.coolDownDelay	Instances	Define coolDown delay time in seconds for Instance
caronte.instance.aws.asg.filters	Instances/aws	Tags filters to define Aws AutoscalingGroup

Configuration Sample

Scale based on Aws - CloudWatch metric store

 my-service:
    image: my-service
    deploy:
      replicas: 1
      labels:
        caronte.enable: "true"
        caronte.scale.max: 8
        caronte.scale.min: 1
        caronte.scale.step: 2
        caronte.scale.service.coolDown: 10
        caronte.metric.scaleDownThreshold: 0
        caronte.metric.scaleUpThreshold: 0
        caronte.metric.store: "cloudwatch"
        caronte.metric.query: "SEARCH('{AWS/SQS,QueueName}my-queue-name MetricName=\"NumberOfMessagesDeleted\"', 'Average', 300)"
        caronte.metric.aws.period: 60
        caronte.instance.provider: "aws"
        caronte.instance.aws.asg.filters: '[{"Name":"key", "Values":["my-asg-tag-name"]}]'

Scale based on Prometheus metric store

 my-service-promehteus-provider:
      image: my-service
      deploy:
        replicas: 1
        labels:
          caronte.enable: "true"
          caronte.scale.max: 8
          caronte.scale.min: 1
          caronte.scale.step: 2
          caronte.scale.service.coolDown: 10
          caronte.metric.scaleDownThreshold: 0
          caronte.metric.scaleUpThreshold: 0
          caronte.metric.store: "prometheus"
          caronte.metric.prometheus.address:  "http://localhost:9090"
          caronte.metric.query: "rate(prometheus_tsdb_head_samples_appended_total[5m])"
          caronte.instance.provider: "aws"
          caronte.instance.aws.asg.filters: '[{"Name":"value", "Values":["my-asg-tag-value"]}]'

Installation

Add Caronte as a swarm service.

 caronte:
   image: xente/caronte
   volumes:
     - /var/run/docker.sock:/var/run/docker.sock
   restart: always
   deploy:
     replicas: 1
     placement:
       constraints:
         - "node.role==manager"

If you want to use Caronte with AWS instance provider you have to provide the AWS keys and Region.

  caronte:
    image: xente/caronte
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    environment: 
     - AWS_ACCESS_KEY_ID=
     - AWS_SECRET_ACCESS_KEY=
     - AWS_DEFAULT_REGION=
    restart: always
    deploy:
      replicas: 1
      placement:
        constraints:
          - "node.role==manager"