Observe

Anyone who ever ran something in production will tell you that the job is not done once the pipeline is running. You need to monitor it, trace it, and make sure it’s healthy. This section will explain how to do that with Wombat.

HTTP Health Checks

Wombat serves two HTTP endpoints for health checks:

• /ping can be used as a liveness probe as it always returns a 200.
• /read can be used as a readiness probe as it serves a 200 only when both the input and output are connected, otherwise a 503 is returned.

The http section of the configuration file can be used to configure the health check endpoints as well as the http server itself.

Logging

Logging in wombat can be customized to your needs in the logging section of the configuration file. By default Wombat logs to stdout and stderr, but it’s possible to configure it to log to a file.

Metrics

Wombat exposes lots of metrics either to Statsd, Prometheus, Cloudwatch or for debugging purposes an HTTP endpoint that returns a JSON formatted object.

The target destination of Wombat metrics is configurable from the metrics section, where it’s also possible to rename and restrict the metrics that are emitted with mappings.

Tracing

Wombat also emits opentracing events to a tracer of your choice, which can be used to visualise the processors within a pipeline.