evaluateGate ran on every trigger regardless of TRIGGER_MOLLIFIER_ENABLED.
With the flag off (the default everywhere it hasn't been opted in), the
gate still produced a `pass_through` decision after allocating a
GateInputs object, spreading defaultGateDependencies inside evaluateGate,
and incrementing the `mollifier.decisions{outcome=pass_through}` OTel
counter. Cheap individually, but triggerTask is the hottest code path in
the system — multiply by trigger rate and the unnecessary work compounds.
Guard the gate call with a direct env.TRIGGER_MOLLIFIER_ENABLED check at
the call site. When the flag is off, mollifierOutcome is null and the
downstream `mollifierOutcome?.action === "mollify"` branch skips the
buffer dual-write entirely — zero allocation, zero counter increment on
the disabled path. When the flag is on, behaviour is unchanged.
Lost-signal note: with mollifier off, we no longer count "pass_through"
decisions in the OTel counter (the gate never runs). That's a non-issue
— "pass_through count when feature is off" is just total trigger rate,
which is already observable via the trigger handler's own spans/counters
upstream. The gate counter remains the source of truth for the
mollify/shadow/pass_through ratio when the feature is on, which is the
load-bearing signal.
Dan Sutton
5255c47599