DNM(yet): Use 3 cores for Bulletin westend parachain

examples/assign_cores.js

@@ -0,0 +1,69 @@
+import { createClient } from 'polkadot-api';
+import { getWsProvider } from 'polkadot-api/ws-provider';
+import { Enum } from '@polkadot-api/substrate-bindings';
+import { cryptoWaitReady } from '@polkadot/util-crypto';
+import { newSigner } from './common.js';
+import { westend } from './.papi/descriptors/dist/index.mjs';
+
+// Command line arguments: [relay_ws_url] [para_id] [num_cores] [seed]
+const args = process.argv.slice(2);
+const RELAY_WS = args[0] || 'ws://localhost:9942';
+const PARA_ID = parseInt(args[1] || '2487');
+const NUM_CORES = parseInt(args[2] || '3');
+const SEED = args[3] || '//Alice';
+
+async function main() {
+    await cryptoWaitReady();
+
+    console.log(`Connecting to relay chain at ${RELAY_WS}...`);
+    const client = createClient(getWsProvider(RELAY_WS));
+    const api = client.getTypedApi(westend);
+
+    const { signer } = newSigner(SEED);
+
+    // Build assignCore calls for each core
+    const calls = [];
+    for (let core = 0; core < NUM_CORES; core++) {
+        const call = api.tx.Coretime.assign_core({
+            core,
+            begin: 0,
+            assignment: [
+                [Enum("Task", PARA_ID), 57600]
+            ],
+            end_hint: undefined,
+        }).decodedCall;
+        calls.push(call);
+        console.log(`  Prepared assignCore(core=${core}, paraId=${PARA_ID}, parts=57600)`);
+    }
+
+    // Batch all assign calls and wrap in sudo
+    const batch = api.tx.Utility.batch_all({ calls });
+    const sudoTx = api.tx.Sudo.sudo({ call: batch.decodedCall });
+
+    console.log(`Submitting sudo batchAll to assign ${NUM_CORES} cores to para ${PARA_ID}...`);
+
+    await new Promise((resolve, reject) => {
+        const sub = sudoTx.signSubmitAndWatch(signer).subscribe({
+            next: (ev) => {
+                console.log(`  Event: ${ev.type}`);
+                if (ev.type === "txBestBlocksState" && ev.found) {
+                    console.log(`Included in block: ${ev.block.hash}`);
+                    console.log(`Successfully assigned ${NUM_CORES} cores to para ${PARA_ID}`);
+                    sub.unsubscribe();
+                    resolve();
+                }
+            },
+            error: (err) => {
+                sub.unsubscribe();
+                reject(err);
+            },
+        });
+    });
+
+    client.destroy();
+}
+
+main().catch((err) => {
+    console.error('Error:', err.message || err);
+    process.exit(1);
+});

examples/justfile

@@ -195,6 +195,19 @@ bulletin-westend-parachain-zombienet-start test_dir runtime="bulletin-westend-ru
     echo "   Waiting for chain to start (180 seconds)..."
     sleep 180
 
+# Assign multiple coretime cores to a parachain on the relay chain via sudo.
+# Requires PAPI descriptors for the relay chain (run papi-generate-relay first).
+# Parameters:
+#   relay_ws_url - WebSocket URL of the relay chain node (default: ws://localhost:9942)
+#   para_id - Parachain ID to assign cores to (default: 2487)
+#   num_cores - Number of cores to assign (default: 3)
+#   seed - Sudo account seed (default: //Alice)
+assign-cores relay_ws_url="ws://localhost:9942" para_id="2487" num_cores="3" seed="//Alice": npm-install
+    #!/usr/bin/env bash
+    set -e
+    echo "Assigning {{ num_cores }} coretime cores to para {{ para_id }} on {{ relay_ws_url }}..."
+    node assign_cores.js "{{ relay_ws_url }}" "{{ para_id }}" "{{ num_cores }}" "{{ seed }}"
+
 # Check if Docker is available and running
 _check-docker:
     #!/usr/bin/env bash
@@ -355,6 +368,16 @@ papi-generate ws_url="ws://localhost:10000": npm-install
     echo "🔧 Generating PAPI descriptors from {{ ws_url }}..."
     npx papi add -w "{{ ws_url }}" bulletin
 
+# Generate PAPI descriptors for the relay chain (needed for assign-cores)
+# Parameters:
+#   relay_ws_url - WebSocket URL of the relay chain node (default: ws://localhost:9942)
+papi-generate-relay relay_ws_url="ws://localhost:9942": npm-install
+    #!/usr/bin/env bash
+    set -e
+
+    echo "🔧 Generating PAPI descriptors for relay chain from {{ relay_ws_url }}..."
+    npx papi add -w "{{ relay_ws_url }}" westend
+
 # Setup all services using Docker for IPFS
 # Parameters:
 #   runtime - Runtime to build and run (e.g., "bulletin-polkadot-runtime", "bulletin-westend-runtime")
@@ -375,6 +398,12 @@ setup-services test_dir runtime: npm-install
     # Generate PAPI descriptors from running node.
     just papi-generate
 
+    # For parachain: generate relay chain descriptors and assign coretime cores
+    if [ "{{ runtime }}" = "bulletin-westend-runtime" ]; then
+        just papi-generate-relay
+        just assign-cores
+    fi
+
     # Start IPFS
     echo "🔧 Tearing down Docker services if they are running..."
     just ipfs-shutdown "{{ test_dir }}"

runtimes/bulletin-westend/src/lib.rs

@@ -78,7 +78,11 @@ use sp_runtime::{
 #[cfg(feature = "std")]
 use sp_version::NativeVersion;
 use sp_version::RuntimeVersion;
-use testnet_parachains_constants::westend::{consensus::*, currency::*, fee::WeightToFee, time::*};
+use testnet_parachains_constants::westend::{currency::*, fee::WeightToFee, time::*};
+// Import consensus constants but override the ones we need for elastic scaling (3 cores, 2s blocks).
+use testnet_parachains_constants::westend::consensus::{
+	MAXIMUM_BLOCK_WEIGHT, RELAY_CHAIN_SLOT_DURATION_MILLIS,
+};
 use weights::{BlockExecutionWeight, ExtrinsicBaseWeight, RocksDbWeight};
 use xcm::{prelude::*, Version as XcmVersion};
 #[cfg(feature = "runtime-benchmarks")]
@@ -91,6 +95,11 @@ use xcm_runtime_apis::{
 	fees::Error as XcmPaymentApiError,
 };
 
+// Override consensus constants for elastic scaling (3 cores, 2s blocks).
+const SLOT_DURATION: u64 = 2000;
+const BLOCK_PROCESSING_VELOCITY: u32 = 3;
+const UNINCLUDED_SEGMENT_CAPACITY: u32 = 6;
+
 /// The address format for describing accounts.
 pub type Address = MultiAddress<AccountId, ()>;
 

zombienet/bulletin-westend-local.toml

@@ -12,6 +12,13 @@ default_command = "{{POLKADOT_BINARY_PATH}}"
 default_args = ["-lruntime=debug,xcm=trace"]
 chain = "westend-local"
 
+[relaychain.genesis.runtimeGenesis.patch.configuration.config.scheduler_params]
+num_cores = 3
+
+[relaychain.genesis.runtimeGenesis.patch.configuration.config.async_backing_params]
+allowed_ancestry_len = 6
+max_candidate_depth = 6
+
 [[relaychain.nodes]]
 name = "alice"
 validator = true
@@ -30,10 +37,27 @@ balance = 2000000000000
 # WebSocket P2P on p2p_port + 1 for smoldot light client support
 args = ["--listen-addr", "/ip4/0.0.0.0/tcp/30434/ws"]
 
+[[relaychain.nodes]]
+name = "charlie"
+validator = true
+
+[[relaychain.nodes]]
+name = "dave"
+validator = true
+
+[[relaychain.nodes]]
+name = "eve"
+validator = true
+
+[[relaychain.nodes]]
+name = "ferdie"
+validator = true
+
 [[parachains]]
 id = 2487
 chain_spec_path = "./zombienet/bulletin-westend-spec.json"
 cumulus_based = true
+num_cores = 3
 
 [[parachains.collators]]
 name = "bulletin-westend-collator-1"
@@ -42,6 +66,7 @@ validator = true
 p2p_port = 10001
 rpc_port = 10000
 args = [
+	"--authoring=slot-based",
 	"--ipfs-server",
 	# Increase tx pool from 20->64 MiB
 	# "--pool-kbytes 65536",
@@ -58,6 +83,7 @@ validator = true
 p2p_port = 12347
 rpc_port = 12346
 args = [
+	"--authoring=slot-based",
 	"--ipfs-server",
 	# Increase tx pool from 20->64 MiB
 	# "--pool-kbytes 65536",