synth

Overview ¶

Command synth fills the sample store of a continuous step with years of synthetic data, and creates the DAG and the run that the web UI needs to show it.

Usage:

go run ./internal/samples/cmd/synth --dir <dagu home> --dag <name> \
    --years 3 --interval 1s --seed 1 [--status running|succeeded]

The directory is a Dagu home: the command writes <dir>/dags/<name>.yaml (one continuous step, named ping) and one run under <dir>/data/dag-runs. Start the server with DAGU_HOME=<dir> and open the run of the DAG.

The data covers the last --years years, ending now. The older part is written into the minute, hour and day tiers directly, the last 26 hours are recorded through a Recorder with a clock that the command moves, so that the raw tier and the tiers have the layout of a real run. The latency is about 40 ms with a daily rhythm and rare spikes. The availability is 99.9x percent, with isolated failures and a few outages of seconds, minutes and hours.

With --status succeeded the Recorder is closed (a stopped event), and the run is a finished run. With --status running (the default) the store is flushed and left open as a run that is still going.

The run ID is "synth-<seed>". The command stops with an error when the run or the store exists already.