activity_cutoff_factor

activity_cutoff_factor sets the inactivity window as a fraction of the epoch length instead of an absolute block count: the effective activity_cutoff is factor × tempo / 1000 blocks. Because the window scales with tempo, a subnet that changes its epoch cadence keeps the same number of epochs of tolerance rather than a fixed wall-clock window.

How it works

get_activity_cutoff_blocks (pallets/subtensor/src/utils/misc.rs) computes factor_milli × tempo / 1000, clamped to at least 1 block, and the epoch uses that value to mask inactive validators out of consensus (see activity_cutoff for the masking mechanics).

The factor is per-mille: 1,000 means one full tempo, 13,889 (the default) means ~13.9 tempos — 5,000 blocks (~16.7 hours) at the default tempo of 360, matching the legacy absolute cutoff. Bounds are 1,000–50,000 (one to fifty tempos).

Reading and setting

Inspect with:

btcli sudo get --netuid N --name activity_cutoff_factor

Owner-settable:

btcli sudo set --netuid N --name activity_cutoff_factor --value 13889

This dispatches sudo_set_activity_cutoff_factor (AdminUtils), owner-or-root: the owner path is rate-limited (once per ~2 tempos by default) and respects the admin freeze window; root bypasses both. It supersedes the legacy absolute-blocks sudo_set_activity_cutoff, whose stored value the epoch ignores.

Related

activity_cutoff · tempo · kappa · max_validators · weights_rate_limit