external_detector_example.rst

External detector example

This software is pre-production and should not be deployed to production servers.

Before running the example you must:

• Set up Mesos cluster with Aurora framework.
• Be able to connect to Mesos operator API available at https://127.0.0.1:5051

Assuming that external implementation of detector is provided as external_package in example module and called ExampleDetector defined as:

#example/external_package.py

from owca import detectors
from owca import mesos
from owca import metrics


class ExampleDetector(detectors.AnomalyDetector):
    """Always return anomaly for given task."""

    def __init__(self, task_id: mesos.TaskId):
        self.task_id = task_id

    def detect(
            self,
            platform: Platform,
            tasks_measurements: TasksMeasurements,
            tasks_resources: TasksResources,
            tasks_labels: TasksLabels
            ) -> (List[Anomaly], List[Metric]):
        anomalies = [
            detectors.ContentionAnomaly(
                resource=detectors.ContendedResource.CPUS
                contended_task_id='task1',
                contending_task_ids=['task2', 'task3']
                metrics=[Metric(name="a_threshold", value=66.6, type="gauge")]
            )
        ]
        debugging_metrics = [
            metrics.Metric(
                name='some_debug',
                value=2,
                labels=dict(
                    version=2,
                )
            )
        ]
        return anomalies, debugging_metrics

when configuration file mesos_external_detector.yaml is used:

runner: !DetectionRunner
  node: !MesosNode
  action_delay: 1.
  storage: !LogStorage
  detector: !ExampleDetector
    task_id: 'some_task_id'

you can run OWCA in following way:

dist/owca.pex -c configs/mesos_external_detector.yaml -r example.external_package:ExampleDetector -l debug

you will see similar output:

2018-07-13 14:51:32,829 DEBUG    {MainThread} [owca.logger] level=DEBUG
2018-07-13 14:51:32,829 DEBUG    {MainThread} [owca.main] started PID=30048
2018-07-13 14:51:32,913 DEBUG    {MainThread} [owca.storage] [Metric(name='platform_dummy', value=1, labels={}, type=None, help=None)]
2018-07-13 14:51:32,913 DEBUG    {MainThread} [owca.storage] [Metric(name='anomaly', value=1, labels={'task_id': 'task_id', 'resource': <ContendedResource.CPUS: 'cpus'>, 'uuid': <bound method ContentionAnomaly.uuid of ContentionAnomaly(task_ids=['task_id'], resource=<ContendedResource.CPUS: 'cpus'>)>}, type=<MetricType.COUNTER: 'counter'>, help=None), Metric(name='some_debug', value=2, labels={'version': 2}, type=None, help=None)]

Register API (optionally)

Instead of providing a class as command line argument you can register it using annotations:

#example_package/example_module.py

...
from owca import config

@config.register
class ExampleDetector(detectors.AnomalyDetector):
    ...

then you can run OWCA just providing configuration file:

dist/owca.pex -c example.yaml -l debug