Marathon Metrics Forwarder

The Marathon Metrics Forwarder is a lightweight service which uses the Marathon API to allow developers to expose metrics endpoints for forwarding to a collector without having to run any other sidecars or eventing out metrics. Either through Kafka or directly to a collection endpoint. This collector makes no expectation around your metrics formats but merely collects them to then be consumed off a queue.

Setup

1. Marathon must be used to deploy applications, either containers or native MESOS containers
2. In your Marathon labels, you must supply the label "METRICS_ENDPOINT" for it to be registered with the metrics collection service.
3. Start the marathon metrics forwarder (preferably inside Marathon) with the environment variables and watch the metrics roll in.

Configuration

Marathon label configuration

metrics_endpoint - Metrics endpoint (excluding domain). Ex: "/metrics" or "/metrics.json" Required

metrics_endpoint_port - Allows to override which port the metrics forwarder will request metrics on. Defaults to port0 in the marathon config. Optional

metrics_frequency - Metrics collection frequency (in seconds). Defaults to 5. Optional

Collector configuration

MARATHON_URL - Marathon URL (for service discovery). Defaults to 'http://localhost:8080'

KAFKA_TOPIC - Kafka Topic name. Defaults to 'metrics_topic'.

ZOOKEEPER_QUORUM - Comma separated list of Zookeeper hosts (optionally including ZNODE path). Defaults to 'localhost:2181'.

CLEARUP_TIMEOUT - How long before a failed check is ejected from memory (in seconds). Defaults to 60.

CLEARUP_FREQUENCY - How frequently to check for failed checks for clearup (in seconds). Defaults to 60.

REFRESH_FREQUENCY - How frequently to check for new tasks (in seconds). Defaults to 60.

API

GET /v1/timers

Gets a list of available scrapers (timers)

Enhancements

• Listen to the Marathon event bus to know when new instances are started and stopped
• Refactor Kafka element to be a plugin to allow multiple backends for receiving metrics
• Create plugin interface to take certain metrics endpoints and allow for parsing pre-sending (such as Prometheus to JSON, JSON to Line Protocol etc.)
• Support basic auth for Marathon URL
• Support publicly valid HTTPS for services (trivial)