HasMigrationRun

Storage Map v301 → v411 Changed in v411

Tracks whether specific migrations have been executed.

Queried by: developers

The Big Picture

This is internal bookkeeping for runtime migrations. When the Drand pallet upgrades, it may need to run one-time migrations. This storage tracks which have executed to prevent re-running.

Why This Matters

Mostly internal - you rarely need this unless debugging migration issues during upgrades.

Example Scenario

Query HasMigrationRun('v2_upgrade') returns true - that migration already executed.

Common Questions

Should I ever modify this?: No - this is managed by the runtime upgrade process. Manual modification could cause migrations to re-run or skip incorrectly.

Use Cases

Debug migration execution during chain upgrades
Verify migration state for troubleshooting

From Chain Metadata

Storage for migration run status

Purpose & Usage

Purpose

Internal migration tracking to prevent duplicate execution of one-time migrations.

Common Query Patterns

Check if a migration has already run
Debug migration issues during upgrades

Notes

Maps migration identifier to boolean
Used internally during runtime upgrades

Query Keys

#	Name	Type	Description
1	migrationName raw: key1	Vec<u8> Vec Vec<T>	key1 (Vec<u8>)

Stored Value

bool

value (bool)

Code Examples

import { createClient, Binary } from "polkadot-api";
import { getWsProvider } from "polkadot-api/ws";
import { sub } from "@polkadot-api/descriptors"; // generated by: npx papi add sub -w wss://entrypoint-finney.opentensor.ai:443

const client = createClient(getWsProvider("wss://entrypoint-finney.opentensor.ai:443"));
const api = client.getTypedApi(sub);

// Query HasMigrationRun storage
const key1 = Binary.fromOpaque(new Uint8Array(0));

const result = await api.query.Drand.HasMigrationRun.getValue(key1);
console.log("HasMigrationRun:", result);

Version History

Version:

v301 block 6,205,194 Added

v316–v319 · runtime versions skipped on chain (never deployed)

v320 block 6,523,566 Internal re-bind

v324–v325 · runtime versions skipped on chain (never deployed)

v326 block 6,608,228 Internal re-bind

v327–v333 · runtime versions skipped on chain (never deployed)

v334 block 6,811,690 Internal re-bind

v353–v360 · runtime versions skipped on chain (never deployed)

v361 block 7,063,679 Internal re-bind

v363–v364 · runtime versions skipped on chain (never deployed)

v365 block 7,135,419 Internal re-bind

v378–v384 · runtime versions skipped on chain (never deployed)

v385 block 7,782,670 Internal re-bind

v386–v390 · runtime versions skipped on chain (never deployed)

v391 block 7,782,857 Internal re-bind

v394–v400 · runtime versions skipped on chain (never deployed)

v401 block 8,036,576 Internal re-bind

v403–v410 · runtime versions skipped on chain (never deployed)

v411 block 8,283,784 Internal re-bind Current

Runtime Info

View Source

Pallet: Drand
Storage Kind: Map
First Version: v301
Current Version: v411

Back to Drand Storage