pr_3952.prdoc

title: Storage bound the XCMP queue pallet

doc:
  - audience: Runtime Dev
    description: |
      Enforce upper limits for the number of active XCMP channels, the number of outgoing XCMP
      messages per channel and the number of signals per channel.

      ## Integration

      If you see this error in your try-runtime-cli:  
      ```pre
      Max message size for channel is too large. This means that the V5 migration can be front-run and an
      attacker could place a large message just right before the migration to make other messages un-decodable.
      Please either increase `MaxPageSize` or decrease the `max_message_size` for this channel. Channel max:
      102400, MaxPageSize: 65535
      ```

      Then increase the `MaxPageSize` of the `cumulus_pallet_xcmp_queue` to something like this:
      ```rust
      type MaxPageSize = ConstU32<{ 103 * 1024 }>;
      ```

migrations:
  db: []

  runtime:
    - reference: cumulus_pallet_xcmp_queue::migration::v5::MigrateV4ToV5
      description: A No-OP migration is deployed to ensure that all `BoundedVec`s` still decode as expected.

crates:
  - name: cumulus-pallet-xcmp-queue
    bump: major

host_functions: []