Strategy Monitoring

Monitoring keeps a strategy healthy across all execution modes. Planar's live infrastructure runs background watchers and tasks that keep local state in sync with the exchange; monitoring is about watching those watchers and reacting when they degrade.

Watchers

A Watcher is an interface over a data feed — OHLCV candles, trades, order books, balances, or positions. Watchers fetch at fixed intervals, process the raw data into a view (usually a DataFrame), and optionally flush to storage.

Key functions (full reference in Watchers):

Function	Purpose
`get`	Retrieve the processed view (e.g. a `DataFrame`)
`length`	Number of elements in the buffer
`last`	Most recent raw buffer value
`isstale`	Whether the watcher is degraded (can't fetch new data)
`fetch!`	Force an immediate data fetch
`flush!`	Force a buffer flush to storage
`delete!` / `deleteat!`	Delete watcher data, optionally within a date range
`push!` / `pop!`	Add or remove tracked elements (e.g. symbols)
`stop` / `start`	Stop and restart the watcher

Detecting Stale Watchers

isstale is the primary health signal. A watcher that reports stale for several consecutive intervals is likely disconnected from its exchange or third-party API — check connectivity, rate limits, and API credentials. See Troubleshooting for common causes.

Live Mode Background Tasks

In live mode, the following background tasks keep local state current and are worth monitoring:

Balance watcher - Tracks account balances. In spot trading it updates the strategy's main currency cash and all universe currencies; in derivatives it updates only the main currency.
Positions watcher - Active when margin is used. The contract counts of open positions represent the cash of the long/short Position in the AssetInstance.
Order-event task - Monitors order events for an asset; starts when an order is placed and stops after a period with no open orders.
Trade-event task - Monitors trade events for an asset; starts and stops with the order-event task.

If an order is placed but no trade event is observed, the order call! returns missing (created but not yet executed). A persistent absence of events — with the synced=true fallback force-fetching updates — suggests the background tasks have stalled.

Monitoring in Simulation and Paper

Simulation: no background tasks run; the backtest loop is the only consumer of data.
Paper: watchers run against live market data, so treat paper mode as a dry run of the live monitoring setup, including spread and latency checks (see Paper Mode).

Alerts

Define alert conditions on the signals above: