otto monitor¶

otto monitor launches an interactive performance dashboard that collects CPU, memory, disk, and network metrics from remote hosts in real time.

Live mode¶

By default, otto monitor polls every real host in the lab. Docker container hosts are excluded — they aren’t operated on as part of the host fleet:

otto --lab my_lab monitor

Selecting hosts¶

Pass a regex to --hosts (matched against host IDs via re.search) to narrow the live host set:

otto --lab my_lab monitor --hosts 'router|switch'
otto --lab my_lab monitor --hosts router1

Omit the option to monitor every real host in the lab (Docker containers excluded).

Collection interval¶

Control how often metrics are collected with --interval (default: 5 seconds, minimum: 1 second):

otto --lab my_lab monitor --interval 2.0

Persisting data¶

Use --db to write collected metrics to a SQLite file for later viewing:

otto --lab my_lab monitor --db metrics.db

Historical mode¶

View previously collected data by passing --file:

otto --lab my_lab monitor --file metrics.db
otto --lab my_lab monitor --file metrics.json

Supported formats: .db (SQLite) and .json.

Web dashboard¶

In both modes, otto serves an interactive web dashboard. By default it listens on port 8000. The dashboard shows:

• Live metric graphs (CPU, memory, disk, network)

• Timeline with events

• Per-host breakdowns

Monitoring during a test run¶

Pass --monitor to otto test to collect metrics for the entire run. Per-test start/end events are emitted automatically and the captured data is written to <output_dir>/monitor.json at exit:

otto --lab my_lab test --monitor TestPerformance
otto --lab my_lab test --monitor --monitor-interval 2 --monitor-hosts router TestPerformance
otto --lab my_lab test --monitor --monitor-output run.db TestPerformance

Reload a captured run in the dashboard via otto monitor --file <path>.

Monitoring from test suites¶

You can also start the monitor programmatically from within a single test:

class TestPerformance(OttoSuite[_Options]):

    async def test_load(self, suite_options: _Options) -> None:
        await self.startMonitor(hosts=[host1, host2])
        await self.addMonitorEvent("Load started", color="green")

        # ... run workload ...

        await self.addMonitorEvent("Load complete", color="red")
        await self.stopMonitor()

When both per-suite and --monitor-driven session collectors are active, the per-suite collector takes precedence for that test. Events appear as markers on the dashboard timeline, making it easy to correlate metric changes with test actions.

Custom parsers¶

The monitor uses parsers to extract metrics from command output. By default, all hosts use DEFAULT_PARSERS. You can register custom parsers for specific hosts:

from otto.monitor.collector import MonitorTarget
from otto.monitor.parsers import DEFAULT_PARSERS

MonitorTarget(
    host=gpu_host,
    parsers={
        **DEFAULT_PARSERS,
        "nvidia-smi --query-gpu=utilization.gpu --format=csv,noheader,nounits":
            NvidiaGpuParser(),
    },
)

See otto.monitor.parsers for the built-in parsers and the MetricParser protocol.