AdjustmentAlphaSet

Event Re-added v126 → v127, v133 → v135, v136 → v141, v142 → v148, v149 → v165, v195 → v219, v233 → v247, v252 → v265, v273 → v277, v290 → v315, v320 → v326, v334 → current #53

Emitted when difficulty adjustment alpha parameter is changed.

View events on chain

Useful for: minersvalidatorssubnet ownersanalyticsdevelopers

The Big Picture

The adjustment alpha controls how aggressively difficulty changes at each interval. Higher alpha means larger swings - difficulty can spike or drop dramatically. Lower alpha means gentler adjustments - difficulty changes gradually. This affects registration cost predictability and stability.

Why This Matters

Alpha determines whether difficulty changes are dramatic or gentle. High alpha subnets can see difficulty double or halve in one adjustment. Low alpha subnets change gradually. Understanding this helps you predict and plan around difficulty swings.

Example Scenario

Subnet 7 had high difficulty volatility due to aggressive alpha. They lower alpha to smooth things out. AdjustmentAlphaSet fires. Future difficulty adjustments will be smaller - no more 2x spikes after busy periods. Registration costs become more predictable.

Common Questions

What's a typical alpha value?: Varies by subnet and desired volatility. Check your subnet's current value. Higher = more volatile, lower = more stable but slower to react to demand changes.
Can I predict the next difficulty from alpha?: Roughly. Alpha + adjustment interval + registration rate = expected difficulty change. But it's probabilistic - actual registrations vary.
Does alpha affect both PoW and burn difficulty?: Usually yes - they're typically adjusted together. Check your subnet's specific implementation for whether they can differ.

Use Cases

Track difficulty adjustment sensitivity
Predict difficulty change magnitude
Monitor subnet registration tuning
Build difficulty modeling tools

How to Use This Event

→ Track alpha to understand difficulty volatility
→ Monitor for changes affecting registration planning
→ Build difficulty volatility models

From Chain Metadata

setting the adjustment alpha on a subnet.

Triggers

Preconditions

Caller has admin/sudo privileges

Effects

Postconditions

AdjustmentAlpha updated for subnet

Side Effects

Controls how aggressively difficulty adjusts

Event Data

#	Name	Type	Description
0	arg0	u16	Event field #0 (u16)
1	arg1	u64	Event field #1 (u64)

Code Examples

import { ApiPromise, WsProvider } from "@polkadot/api";
import { stringCamelCase } from "@polkadot/util";

const provider = new WsProvider("wss://entrypoint-finney.opentensor.ai:443");
const api = await ApiPromise.create({ provider });

// Subscribe to AdjustmentAlphaSet events
api.query.system.events((events) => {
  events
    .filter(({ event }) =>
      event.section === stringCamelCase("SubtensorModule") &&
      event.method === "AdjustmentAlphaSet"
    )
    .forEach(({ event }) => {
      console.log("AdjustmentAlphaSet:", event.data.toHuman());
    });
});

Version History

Version:

v126 block 806,011 2 args

v133 block 1,404,224 2 args

v136 block 1,756,781 2 args

v142 block 2,543,779 2 args

v149 block 3,014,339 2 args

v195 block 3,791,350 2 args

v233 block 4,920,350 2 args

v252 block 5,163,656 2 args

v273 block 5,659,032 2 args

v290 block 5,947,548 2 args

v320 block 6,523,566 2 args

v334 block 6,811,690 2 args Current

Runtime Info

View Source

Pallet Index: 7
Event Index: 53
First Version: v126
Current Version: v393

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