diff --git a/404.html b/404.html index 557fc8c..c103dd8 100644 --- a/404.html +++ b/404.html @@ -91,7 +91,7 @@ diff --git a/approved/0001-agile-coretime.html b/approved/0001-agile-coretime.html index c3f7c29..4bc1ee1 100644 --- a/approved/0001-agile-coretime.html +++ b/approved/0001-agile-coretime.html @@ -90,7 +90,7 @@ diff --git a/approved/0005-coretime-interface.html b/approved/0005-coretime-interface.html index 14c7082..92ef6ef 100644 --- a/approved/0005-coretime-interface.html +++ b/approved/0005-coretime-interface.html @@ -90,7 +90,7 @@ diff --git a/approved/0007-system-collator-selection.html b/approved/0007-system-collator-selection.html index 6878c3e..525c262 100644 --- a/approved/0007-system-collator-selection.html +++ b/approved/0007-system-collator-selection.html @@ -90,7 +90,7 @@ diff --git a/approved/0008-parachain-bootnodes-dht.html b/approved/0008-parachain-bootnodes-dht.html index b378b3a..6bf398c 100644 --- a/approved/0008-parachain-bootnodes-dht.html +++ b/approved/0008-parachain-bootnodes-dht.html @@ -90,7 +90,7 @@ diff --git a/approved/0009-improved-net-light-client-requests.html b/approved/0009-improved-net-light-client-requests.html index 5023187..a6a3762 100644 --- a/approved/0009-improved-net-light-client-requests.html +++ b/approved/0009-improved-net-light-client-requests.html @@ -90,7 +90,7 @@ diff --git a/approved/0010-burn-coretime-revenue.html b/approved/0010-burn-coretime-revenue.html index c9171d5..8800a42 100644 --- a/approved/0010-burn-coretime-revenue.html +++ b/approved/0010-burn-coretime-revenue.html @@ -90,7 +90,7 @@ diff --git a/approved/0012-process-for-adding-new-collectives.html b/approved/0012-process-for-adding-new-collectives.html index 9c27663..a2ede05 100644 --- a/approved/0012-process-for-adding-new-collectives.html +++ b/approved/0012-process-for-adding-new-collectives.html @@ -90,7 +90,7 @@ diff --git a/approved/0013-prepare-blockbuilder-and-core-runtime-apis-for-mbms.html b/approved/0013-prepare-blockbuilder-and-core-runtime-apis-for-mbms.html index 9951a76..1e64fca 100644 --- a/approved/0013-prepare-blockbuilder-and-core-runtime-apis-for-mbms.html +++ b/approved/0013-prepare-blockbuilder-and-core-runtime-apis-for-mbms.html @@ -90,7 +90,7 @@ diff --git a/approved/0014-improve-locking-mechanism-for-parachains.html b/approved/0014-improve-locking-mechanism-for-parachains.html index e9191de..8dde1b3 100644 --- a/approved/0014-improve-locking-mechanism-for-parachains.html +++ b/approved/0014-improve-locking-mechanism-for-parachains.html @@ -90,7 +90,7 @@ diff --git a/approved/0022-adopt-encointer-runtime.html b/approved/0022-adopt-encointer-runtime.html index ceac1ad..b235a9a 100644 --- a/approved/0022-adopt-encointer-runtime.html +++ b/approved/0022-adopt-encointer-runtime.html @@ -90,7 +90,7 @@ diff --git a/approved/0026-sassafras-consensus.html b/approved/0026-sassafras-consensus.html index 792194e..eb23e3f 100644 --- a/approved/0026-sassafras-consensus.html +++ b/approved/0026-sassafras-consensus.html @@ -90,7 +90,7 @@ diff --git a/approved/0032-minimal-relay.html b/approved/0032-minimal-relay.html index 2b480ad..50eae50 100644 --- a/approved/0032-minimal-relay.html +++ b/approved/0032-minimal-relay.html @@ -90,7 +90,7 @@ diff --git a/approved/0042-extrinsics-state-version.html b/approved/0042-extrinsics-state-version.html index bf5379f..b7041e7 100644 --- a/approved/0042-extrinsics-state-version.html +++ b/approved/0042-extrinsics-state-version.html @@ -90,7 +90,7 @@ diff --git a/approved/0043-storage-proof-size-hostfunction.html b/approved/0043-storage-proof-size-hostfunction.html index 5e2992e..648a575 100644 --- a/approved/0043-storage-proof-size-hostfunction.html +++ b/approved/0043-storage-proof-size-hostfunction.html @@ -90,7 +90,7 @@ diff --git a/approved/0045-nft-deposits-asset-hub.html b/approved/0045-nft-deposits-asset-hub.html index 5e3df40..db640c8 100644 --- a/approved/0045-nft-deposits-asset-hub.html +++ b/approved/0045-nft-deposits-asset-hub.html @@ -90,7 +90,7 @@ diff --git a/approved/0047-assignment-of-availability-chunks.html b/approved/0047-assignment-of-availability-chunks.html index 55efd8e..f529d3f 100644 --- a/approved/0047-assignment-of-availability-chunks.html +++ b/approved/0047-assignment-of-availability-chunks.html @@ -90,7 +90,7 @@ diff --git a/approved/0048-session-keys-runtime-api.html b/approved/0048-session-keys-runtime-api.html index 4084f08..5121baa 100644 --- a/approved/0048-session-keys-runtime-api.html +++ b/approved/0048-session-keys-runtime-api.html @@ -90,7 +90,7 @@ diff --git a/approved/0050-fellowship-salaries.html b/approved/0050-fellowship-salaries.html index 09b953f..052aaf6 100644 --- a/approved/0050-fellowship-salaries.html +++ b/approved/0050-fellowship-salaries.html @@ -90,7 +90,7 @@ diff --git a/approved/0056-one-transaction-per-notification.html b/approved/0056-one-transaction-per-notification.html index 1682ab2..167643a 100644 --- a/approved/0056-one-transaction-per-notification.html +++ b/approved/0056-one-transaction-per-notification.html @@ -90,7 +90,7 @@ diff --git a/approved/0059-nodes-capabilities-discovery.html b/approved/0059-nodes-capabilities-discovery.html index 4558832..784aefb 100644 --- a/approved/0059-nodes-capabilities-discovery.html +++ b/approved/0059-nodes-capabilities-discovery.html @@ -90,7 +90,7 @@ diff --git a/approved/0078-merkleized-metadata.html b/approved/0078-merkleized-metadata.html index 50e5343..c1a4740 100644 --- a/approved/0078-merkleized-metadata.html +++ b/approved/0078-merkleized-metadata.html @@ -90,7 +90,7 @@ diff --git a/approved/0084-general-transaction-extrinsic-format.html b/approved/0084-general-transaction-extrinsic-format.html index cd294c9..9666ecc 100644 --- a/approved/0084-general-transaction-extrinsic-format.html +++ b/approved/0084-general-transaction-extrinsic-format.html @@ -90,7 +90,7 @@ diff --git a/approved/0091-dht-record-creation-time.html b/approved/0091-dht-record-creation-time.html index 2b06a6c..463692c 100644 --- a/approved/0091-dht-record-creation-time.html +++ b/approved/0091-dht-record-creation-time.html @@ -90,7 +90,7 @@ diff --git a/approved/0097-unbonding_queue.html b/approved/0097-unbonding_queue.html index 2994887..44ff84a 100644 --- a/approved/0097-unbonding_queue.html +++ b/approved/0097-unbonding_queue.html @@ -90,7 +90,7 @@ diff --git a/approved/0099-transaction-extension-version.html b/approved/0099-transaction-extension-version.html index 0d969ff..9f42675 100644 --- a/approved/0099-transaction-extension-version.html +++ b/approved/0099-transaction-extension-version.html @@ -90,7 +90,7 @@ diff --git a/approved/0100-xcm-multi-type-asset-transfer.html b/approved/0100-xcm-multi-type-asset-transfer.html index 6d5230d..6e8cab2 100644 --- a/approved/0100-xcm-multi-type-asset-transfer.html +++ b/approved/0100-xcm-multi-type-asset-transfer.html @@ -90,7 +90,7 @@ diff --git a/approved/0101-xcm-transact-remove-max-weight-param.html b/approved/0101-xcm-transact-remove-max-weight-param.html index 9d2e15c..8bc7b26 100644 --- a/approved/0101-xcm-transact-remove-max-weight-param.html +++ b/approved/0101-xcm-transact-remove-max-weight-param.html @@ -90,7 +90,7 @@ diff --git a/approved/0103-introduce-core-index-commitment.html b/approved/0103-introduce-core-index-commitment.html index b415e01..0c1973b 100644 --- a/approved/0103-introduce-core-index-commitment.html +++ b/approved/0103-introduce-core-index-commitment.html @@ -90,7 +90,7 @@ diff --git a/approved/0105-xcm-improved-fee-mechanism.html b/approved/0105-xcm-improved-fee-mechanism.html index 8d3f787..a94921f 100644 --- a/approved/0105-xcm-improved-fee-mechanism.html +++ b/approved/0105-xcm-improved-fee-mechanism.html @@ -90,7 +90,7 @@ diff --git a/approved/0107-xcm-execution-hints.html b/approved/0107-xcm-execution-hints.html index 86bb288..7f20ccd 100644 --- a/approved/0107-xcm-execution-hints.html +++ b/approved/0107-xcm-execution-hints.html @@ -90,7 +90,7 @@ diff --git a/approved/0108-xcm-remove-testnet-ids.html b/approved/0108-xcm-remove-testnet-ids.html index c0ac805..6b594b2 100644 --- a/approved/0108-xcm-remove-testnet-ids.html +++ b/approved/0108-xcm-remove-testnet-ids.html @@ -90,7 +90,7 @@ diff --git a/approved/0122-alias-origin-on-asset-transfers.html b/approved/0122-alias-origin-on-asset-transfers.html index a2a5bb0..1b24b05 100644 --- a/approved/0122-alias-origin-on-asset-transfers.html +++ b/approved/0122-alias-origin-on-asset-transfers.html @@ -90,7 +90,7 @@ diff --git a/approved/0123-pending-code-as-storage-location-for-runtime-upgrades.html b/approved/0123-pending-code-as-storage-location-for-runtime-upgrades.html index d80519c..b30c04a 100644 --- a/approved/0123-pending-code-as-storage-location-for-runtime-upgrades.html +++ b/approved/0123-pending-code-as-storage-location-for-runtime-upgrades.html @@ -90,7 +90,7 @@ diff --git a/approved/0125-xcm-asset-metadata.html b/approved/0125-xcm-asset-metadata.html index 70151eb..480917b 100644 --- a/approved/0125-xcm-asset-metadata.html +++ b/approved/0125-xcm-asset-metadata.html @@ -90,7 +90,7 @@ @@ -406,7 +406,7 @@ This RFC proposes to use the Undefined variant of a collection iden - @@ -420,7 +420,7 @@ This RFC proposes to use the Undefined variant of a collection iden - diff --git a/proposed/0126-introduce-pvq.html b/approved/0126-introduce-pvq.html similarity index 85% rename from proposed/0126-introduce-pvq.html rename to approved/0126-introduce-pvq.html index c9edb6a..870eea0 100644 --- a/proposed/0126-introduce-pvq.html +++ b/approved/0126-introduce-pvq.html @@ -90,7 +90,7 @@ @@ -174,7 +174,7 @@
-

(source)

+

(source)

Table of Contents

diff --git a/index.html b/index.html index 6635b31..23bd223 100644 --- a/index.html +++ b/index.html @@ -90,7 +90,7 @@ diff --git a/introduction.html b/introduction.html index 6635b31..23bd223 100644 --- a/introduction.html +++ b/introduction.html @@ -90,7 +90,7 @@ diff --git a/print.html b/print.html index 961fb44..7a19d89 100644 --- a/print.html +++ b/print.html @@ -91,7 +91,7 @@ @@ -419,421 +419,6 @@ At this point, we compute $\beta\prime_w = \sum_v \beta\prime_{w,v}$ on-chain fo

Synthetic parachain flag

Any rewards protocol could simply be "out voted" by too many slow validators: An increase the number of parachain cores increases more workload, but this creates no-shows if too few validators could handle this workload.

We could add a synthetic parachain flag, only settable by governance, which treats no-shows as positive approval votes for that parachain, but without adding rewards. We should never enable this for real parachains, only for synthetic ones like gluttons. We should not enable the synthetic parachain flag long-term even for gluttonsm, because validators could easily modify their code. Yet, synthetic approval checks might enable pushing the hardware upgrades more agressively over the short-term.

-

(source)

-

Table of Contents

- -

RFC-0126: Introduce PVQ (PolkaVM Query)

-
- - - -
Start DateOct 25, 2024
DescriptionIntroduce PVQ (PolkaVM Query)
AuthorsBryan Chen, Jiyuan Zheng
-
-

Summary

-

This proposal introduces PVQ (PolkaVM Query), a unified query interface that bridges different chain runtime implementations and client tools/UIs. PVQ provides an extension-based system where runtime developers can expose chain-specific functionality through standardized interfaces, while allowing client-side developers to perform custom computations on the data through PolkaVM programs. By abstracting away concrete implementations across chains and supporting both off-chain and cross-chain scenarios, PVQ aims to reduce code duplication and development complexity while maintaining flexibility for custom use cases.

-

Motivation

-

In Substrate, runtime APIs facilitate off-chain clients in reading the state of the consensus system. -However, the APIs defined and implemented by individual chains often fall short of meeting the diverse requirements of client-side developers. -For example, client-side developers may want some aggregated data from multiple pallets, or apply various custom transformations on the raw data. -Additionally, chains often implement different APIs and data types (such as AccountId) for similar functionality, which increases complexity and development effort on the client side. -As a result, client-side developers frequently resort to directly accessing storage (which is susceptible to breaking changes) and reimplementing custom computations on the raw data. This leads to code duplication between the Rust runtime logic and UI JavaScript/TypeScript logic, increasing development effort and introducing potential for bugs.

-

Moreover, the diversity also extends to cross-chain queries.

-

Therefore, a system that serves as an intermediary layer between runtime implementations and client-side implementations with a unified but flexible interface will be beneficial for both sides. It should be able to:

- -

Use cases that will benefit from such a system:

- -

Stakeholders

- -

Explanation

-

The core idea of PVQ is to have a unified interface that meets the aforementioned requirements.

-

On the runtime side, an extension-based system is introduced to serve as a standardization layer across different chains. -Each extension specification defines a set of cohesive APIs. -Runtime developers can freely select which extensions they want to implement, and have full control over how the data is sourced - whether from single or multiple pallet functions, with optional data transformations applied. -The runtime aggregates all implemented extensions into a single unified interface that takes a query program and corresponding arguments, and returns the query result. -This interface will be exposed in two ways: as a Substrate RuntimeAPI for off-chain queries, and as an XCM instruction for cross-chain queries.

-

On the client side or in XCM use cases, the client can easily detect which extensions are supported by a runtime through the metadata API. This allows for runtime feature discovery and enables clients to adapt their behavior based on available functionality. -Client-side developers can encode their desired custom computation logic into the query program and its arguments, while the actual data access happens through runtime-implemented extensions.

-

In conclusion, PVQ involves three components:

- -

PVQ Extension System

-

The PVQ extension system has the following features:

- -

Example Design:

-

The following code declares two extensions: extension_core and extension_fungibles with some associated types.

-
#![allow(unused)]
-fn main() {
-#[extension_decl]
-pub mod extension_core {
-    #[extension_decl::extension]
-    pub trait ExtensionCore {
-        type ExtensionId;
-        fn has_extension(id: Self::ExtensionId) -> bool;
-    }
-}
-
-#[extension_decl]
-pub mod extension_fungibles {
-    #[extension_decl::extension]
-    pub trait ExtensionFungibles {
-        type AssetId;
-        type Balance;
-        type AccountId;
-        fn total_supply(asset: Self::AssetId) -> Self::Balance;
-        fn balance(asset: Self::AssetId, who: Self::AccountId) -> Self::Balance;
-    }
-}
-}
-

The following code implements the extensions, amalgamates them and generates the corresponding metadata.

-
#![allow(unused)]
-fn main() {
-#[extensions_impl]
-pub mod extensions {
-    #[extensions_impl::impl_struct]
-    pub struct ExtensionsImpl;
-
-    #[extensions_impl::extension]
-    impl pvq_extension_core::extension::ExtensionCore for ExtensionsImpl {
-        type ExtensionId = u64;
-        fn has_extension(id: Self::ExtensionId) -> bool {
-            matches!(id, 0 | 1)
-        }
-    }
-
-    #[extensions_impl::extension]
-    impl pvq_extension_fungibles::extension::ExtensionFungibles for ExtensionsImpl {
-        type AssetId = u32;
-        type AccountId = [u8; 32];
-        type Balance = u64;
-        fn total_supply(_asset: Self::AssetId) -> Self::Balance {
-            100
-        }
-        fn balance(_asset: Self::AssetId, _who: Self::AccountId) -> Self::Balance {
-            100
-        }
-    }
-}
-}
- -

Extensions are uniquely identified by a hash value computed from their name and method names. This means that modifying either the extension name or its method names results in a new extension. This design allows new functionality to be added independently of the PVQ core version, enabling a permissionless extension system while keeping the core implementation minimal.

-

The extension ID generation can be expressed mathematically as:

-

$ExtID = twox64(P \parallel E \parallel M_1 \parallel M_2 \parallel ... \parallel M_n)$

-

Where:

- -

PVQ Executor

-

The PVQ Executor provides a unified interface that only takes query programs with corresponding arguments and returns results. It can be formulated as a PVM program-argument invocation, as detailed in Appendix A.8 in the JAM Gray Paper. Specifically, we call it PVQ invocation.

-

Program initialization and Results Return

- -

Host Functions

-

The following host functions are available to PVQ invocations. The index numbers shown below correspond to the values used in the ecalli instruction.

-
    -
  1. extension_call: A unified entry point that routes queries to various extensions. It accepts two parameters:
    2. -
- -

The returned results are stored in registers a0 (pointer) and a1 (length). The output buffer contains the SCALE-encoded return value.

-

All host functions must properly account for and deduct gas based on their computational costs.

-

Example Rust Implementation using PolkaVM SDK:

-
#![allow(unused)]
-fn main() {
-#[polkavm_derive::polkavm_import]
-extern "C" {
-    fn extension_call(extension_id:u64, call_ptr:u32, call_len: u32) -> (u32, u32);
-}
-}
-

PVQ Executor Implementation

-

Practically, the executor has a core method execute to initialize the program and perform argument invocation, which takes:

- -

Example Rust Implementation:

-
#![allow(unused)]
-fn main() {
-pub fn execute(
-    &mut self,
-    program: &[u8],
-    args: &[u8],
-    gas_limit: Option<i64>,
-) -> Result<Vec<u8>, PvqExecutorError> {...}
-
-pub enum PvqExecutorError<UserError> {
-  InvalidProgramFormat,
-  MemoryAccessError(polkavm::MemoryAccessError),
-  Trap,
-  NotEnoughGas,
-  User(UserError),
-  OtherPvmError(polkavm::Error),
-  // Implementors can define additional error variants to differentiate specific panic reasons for internal debugging purposes.
-}
-}
-

Additionally, it provides an initialization method that sets up the PVM execution environment and external interfaces by pre-registering the required host functions:

-

Example Rust Implementation:

-
#![allow(unused)]
-fn main() {
-pub fn new(context: PvqContext) -> Self
-}
-

RuntimeAPI Integration

-

The RuntimeAPI for off-chain query usage includes two methods:

- -

Example PVQ Runtime API:

-
#![allow(unused)]
-fn main() {
-decl_runtime_apis! {
-    pub trait PvqApi {
-        fn execute_query(program: Vec<u8>, args: Vec<u8>, gas_limit: Option<i64>) -> PvqResult;
-        fn metadata() -> Vec<u8>;
-    }
-}
-type PvqResult =  Result<PvqResponse, PvqError>;
-type PvqResponse = Vec<u8>;
-enum PvqError {
-    InvalidProgramFormat,
-    Timeout,
-    Panic(String),
-}
-}
-

Example Metadata:

-
#![allow(unused)]
-fn main() {
-pub struct Metadata {
-    pub types: PortableRegistry,
-    pub extensions: Vec<ExtensionMetadata<PortableForm>>,
-}
-}
-

XCM integration

-

The integration of PVQ into XCM is achieved by adding a new instruction to XCM, as well as a new variant of the Response type in the QueryResponse message.

- -

Operands:

- -
#![allow(unused)]
-fn main() {
-ReportQuery {
-  query: BoundedVec<u8, MaxPvqSize>,
-  max_weight: Weight,
-  info: QueryResponseInfo,
-}
-}
- -

PvqResult is a variant type:

- -

Errors

- -

Drawbacks

-

Performance issues

- -

Testing, Security, and Privacy

- -

Performance, Ergonomics, and Compatibility

-

Performance

-

As a newly introduced feature, PVQ operates independently and does not impact or degrade the performance of existing runtime implementations.

-

Ergonomics

-

From the perspective of off-chain tooling, this proposal streamlines development by unifying multiple chain-specific RuntimeAPIs under a single consistent interface. -This significantly benefits wallet and dApp developers by eliminating the need to handle individual implementations for similar operations across different chains. The proposal also enhances development flexibility by allowing custom computations to be modularly encapsulated as PolkaVM programs that interact with the exposed APIs.

-

Compatibility

-

For RuntimeAPI integration, the proposal defines new APIs, which do not break compatibility with existing interfaces. -For XCM Integration, the proposal does not modify the existing XCM message format, which is backwards compatible.

-

Prior Art and References

-

There are several discussions related to the proposal, including:

- -

Unresolved Questions

- - -

Once PVQ and the aforementioned Facade Project are ready, there are opportunities to consolidate overlapping functionality between the two systems. For example, the metadata APIs could potentially be unified to provide a more cohesive interface for runtime information. This would help reduce duplication and improve maintainability while preserving the distinct benefits of each approach.

(source)

Table of Contents

-

Stakeholders

+

Stakeholders

-

Explanation

+

Explanation

This protocol builds on the existing Collator Selection pallet and its notion of Invulnerables. Invulnerables are collators (identified by their AccountIds) who @@ -1748,27 +1333,27 @@ approximately:

  • of which 15 are Invulnerable, and
  • five are elected by bond.
    • -

    Drawbacks

    +

    Drawbacks

    The primary drawback is a reliance on governance for continued treasury funding of infrastructure costs for Invulnerable collators.

    -

    Testing, Security, and Privacy

    +

    Testing, Security, and Privacy

    The vast majority of cases can be covered by unit testing. Integration test should ensure that the Collator Selection UpdateOrigin, which has permission to modify the Invulnerables and desired number of Candidates, can handle updates over XCM from the system's governance location.

    -

    Performance, Ergonomics, and Compatibility

    +

    Performance, Ergonomics, and Compatibility

    This proposal has very little impact on most users of Polkadot, and should improve the performance of system chains by reducing the number of missed blocks.

    -

    Performance

    +

    Performance

    As chains have strict PoV size limits, care must be taken in the PoV impact of the session manager. Appropriate benchmarking and tests should ensure that conservative limits are placed on the number of Invulnerables and Candidates.

    -

    Ergonomics

    +

    Ergonomics

    The primary group affected is Candidate collators, who, after implementation of this RFC, will need to compete in a bond-based election rather than a race to claim a Candidate spot.

    -

    Compatibility

    +

    Compatibility

    This RFC is compatible with the existing implementation and can be handled via upgrades and migration.

    -

    Prior Art and References

    +

    Prior Art and References

    Written Discussions

    -

    Unresolved Questions

    +

    Unresolved Questions

    None at this time.

    - +

    There may exist in the future system chains for which this model of collator selection is not appropriate. These chains should be evaluated on a case-by-case basis.

    (source)

    @@ -1824,10 +1409,10 @@ appropriate. These chains should be evaluated on a case-by-case basis.

    AuthorsPierre Krieger -

    Summary

    +

    Summary

    The full nodes of the Polkadot peer-to-peer network maintain a distributed hash table (DHT), which is currently used for full nodes discovery and validators discovery purposes.

    This RFC proposes to extend this DHT to be used to discover full nodes of the parachains of Polkadot.

    -

    Motivation

    +

    Motivation

    The maintenance of bootnodes has long been an annoyance for everyone.

    When a bootnode is newly-deployed or removed, every chain specification must be updated in order to take the update into account. This has lead to various non-optimal solutions, such as pulling chain specifications from GitHub repositories. When it comes to RPC nodes, UX developers often have trouble finding up-to-date addresses of parachain RPC nodes. With the ongoing migration from RPC nodes to light clients, similar problems would happen with chain specifications as well.

    @@ -1836,9 +1421,9 @@ When it comes to RPC nodes, UX developers often have trouble finding up-to-date

    Because the list of bootnodes in chain specifications is so annoying to modify, the consequence is that the number of bootnodes is rather low (typically between 2 and 15). In order to better resist downtimes and DoS attacks, a better solution would be to use every node of a certain chain as potential bootnode, rather than special-casing some specific nodes.

    While this RFC doesn't solve these problems for relay chains, it aims at solving it for parachains by storing the list of all the full nodes of a parachain on the relay chain DHT.

    Assuming that this RFC is implemented, and that light clients are used, deploying a parachain wouldn't require more work than registering it onto the relay chain and starting the collators. There wouldn't be any need for special infrastructure nodes anymore.

    -

    Stakeholders

    +

    Stakeholders

    This RFC has been opened on my own initiative because I think that this is a good technical solution to a usability problem that many people are encountering and that they don't realize can be solved.

    -

    Explanation

    +

    Explanation

    The content of this RFC only applies for parachains and parachain nodes that are "Substrate-compatible". It is in no way mandatory for parachains to comply to this RFC.

    Note that "Substrate-compatible" is very loosely defined as "implements the same mechanisms and networking protocols as Substrate". The author of this RFC believes that "Substrate-compatible" should be very precisely specified, but there is controversy on this topic.

    While a lot of this RFC concerns the implementation of parachain nodes, it makes use of the resources of the Polkadot chain, and as such it is important to describe them in the Polkadot specification.

    @@ -1875,10 +1460,10 @@ message Response {

    The maximum size of a response is set to an arbitrary 16kiB. The responding side should make sure to conform to this limit. Given that fork_id is typically very small and that the only variable-length field is addrs, this is easily achieved by limiting the number of addresses.

    Implementers should be aware that addrs might be very large, and are encouraged to limit the number of addrs to an implementation-defined value.

    -

    Drawbacks

    +

    Drawbacks

    The peer_id and addrs fields are in theory not strictly needed, as the PeerId and addresses could be always equal to the PeerId and addresses of the node being registered as the provider and serving the response. However, the Cumulus implementation currently uses two different networking stacks, one of the parachain and one for the relay chain, using two separate PeerIds and addresses, and as such the PeerId and addresses of the other networking stack must be indicated. Asking them to use only one networking stack wouldn't feasible in a realistic time frame.

    The values of the genesis_hash and fork_id fields cannot be verified by the requester and are expected to be unused at the moment. Instead, a client that desires connecting to a parachain is expected to obtain the genesis hash and fork ID of the parachain from the parachain chain specification. These fields are included in the networking protocol nonetheless in case an acceptable solution is found in the future, and in order to allow use cases such as discovering parachains in a not-strictly-trusted way.

    -

    Testing, Security, and Privacy

    +

    Testing, Security, and Privacy

    Because not all nodes want to be used as bootnodes, implementers are encouraged to provide a way to disable this mechanism. However, it is very much encouraged to leave this mechanism on by default for all parachain nodes.

    This mechanism doesn't add or remove any security by itself, as it relies on existing mechanisms. However, if the principle of chain specification bootnodes is entirely replaced with the mechanism described in this RFC (which is the objective), then it becomes important whether the mechanism in this RFC can be abused in order to make a parachain unreachable.

    @@ -1887,22 +1472,22 @@ Furthermore, when a large number of providers (here, a provider is a bootnode) a

    For this reason, an attacker can abuse this mechanism by randomly generating libp2p PeerIds until they find the 20 entries closest to the key representing the target parachain. They are then in control of the parachain bootnodes. Because the key changes periodically and isn't predictable, and assuming that the Polkadot DHT is sufficiently large, it is not realistic for an attack like this to be maintained in the long term.

    Furthermore, parachain clients are expected to cache a list of known good nodes on their disk. If the mechanism described in this RFC went down, it would only prevent new nodes from accessing the parachain, while clients that have connected before would not be affected.

    -

    Performance, Ergonomics, and Compatibility

    -

    Performance

    +

    Performance, Ergonomics, and Compatibility

    +

    Performance

    The DHT mechanism generally has a low overhead, especially given that publishing providers is done only every 24 hours.

    Doing a Kademlia iterative query then sending a provider record shouldn't take more than around 50 kiB in total of bandwidth for the parachain bootnode.

    Assuming 1000 parachain full nodes, the 20 Polkadot full nodes corresponding to a specific parachain will each receive a sudden spike of a few megabytes of networking traffic when the key rotates. Again, this is relatively negligible. If this becomes a problem, one can add a random delay before a parachain full node registers itself to be the provider of the key corresponding to BabeApi_next_epoch.

    Maybe the biggest uncertainty is the traffic that the 20 Polkadot full nodes will receive from light clients that desire knowing the bootnodes of a parachain. Light clients are generally encouraged to cache the peers that they use between restarts, so they should only query these 20 Polkadot full nodes at their first initialization. If this every becomes a problem, this value of 20 is an arbitrary constant that can be increased for more redundancy.

    -

    Ergonomics

    +

    Ergonomics

    Irrelevant.

    -

    Compatibility

    +

    Compatibility

    Irrelevant.

    -

    Prior Art and References

    +

    Prior Art and References

    None.

    -

    Unresolved Questions

    +

    Unresolved Questions

    While it fundamentally doesn't change much to this RFC, using BabeApi_currentEpoch and BabeApi_nextEpoch might be inappropriate. I'm not familiar enough with good practices within the runtime to have an opinion here. Should it be an entirely new pallet?

    - +

    It is possible that in the future a client could connect to a parachain without having to rely on a trusted parachain specification.

    (source)

    Table of Contents

    @@ -1935,9 +1520,9 @@ If this every becomes a problem, this value of 20 is an arbitrary constant that AuthorsPierre Krieger -

    Summary

    +

    Summary

    Improve the networking messages that query storage items from the remote, in order to reduce the bandwidth usage and number of round trips of light clients.

    -

    Motivation

    +

    Motivation

    Clients on the Polkadot peer-to-peer network can be divided into two categories: full nodes and light clients. So-called full nodes are nodes that store the content of the chain locally on their disk, while light clients are nodes that don't. In order to access for example the balance of an account, a full node can do a disk read, while a light client needs to send a network message to a full node and wait for the full node to reply with the desired value. This reply is in the form of a Merkle proof, which makes it possible for the light client to verify the exactness of the value.

    Unfortunately, this network protocol is suffering from some issues:

    Once Polkadot and Kusama will have transitioned to state_version = 1, which modifies the format of the trie entries, it will be possible to generate Merkle proofs that contain only the hashes of values in the storage. Thanks to this, it is already possible to prove the existence of a key without sending its entire value (only its hash), or to prove that a value has changed or not between two blocks (by sending just their hashes). Thus, the only reason why aforementioned issues exist is because the existing networking messages don't give the possibility for the querier to query this. This is what this proposal aims at fixing.

    -

    Stakeholders

    +

    Stakeholders

    This is the continuation of https://github.com/w3f/PPPs/pull/10, which itself is the continuation of https://github.com/w3f/PPPs/pull/5.

    -

    Explanation

    +

    Explanation

    The protobuf schema of the networking protocol can be found here: https://github.com/paritytech/substrate/blob/5b6519a7ff4a2d3cc424d78bc4830688f3b184c0/client/network/light/src/schema/light.v1.proto

    The proposal is to modify this protocol in this way:

    @@ -11,6 +11,7 @@ message Request {
@@ -2007,26 +1592,26 @@ An alternative could have been to specify the child_trie_info for e
 Also note that child tries aren't considered as descendants of the main trie when it comes to the includeDescendants flag. In other words, if the request concerns the main trie, no content coming from child tries is ever sent back.
    
 
    This protocol keeps the same maximum response size limit as currently exists (16 MiB). It is not possible for the querier to know in advance whether its query will lead to a reply that exceeds the maximum size. If the reply is too large, the replier should send back only a limited number (but at least one) of requested items in the proof. The querier should then send additional requests for the rest of the items. A response containing none of the requested items is invalid.
    
 
    The server is allowed to silently discard some keys of the request if it judges that the number of requested keys is too high. This is in line with the fact that the server might truncate the response.
    
-
    Drawbacks
    
+
    Drawbacks
    
 
    This proposal doesn't handle one specific situation: what if a proof containing a single specific item would exceed the response size limit? For example, if the response size limit was 1 MiB, querying the runtime code (which is typically 1.0 to 1.5 MiB) would be impossible as it's impossible to generate a proof less than 1 MiB. The response size limit is currently 16 MiB, meaning that no single storage item must exceed 16 MiB.
    
 
    Unfortunately, because it's impossible to verify a Merkle proof before having received it entirely, parsing the proof in a streaming way is also not possible.
    
 
    A way to solve this issue would be to Merkle-ize large storage items, so that a proof could include only a portion of a large storage item. Since this would require a change to the trie format, it is not realistically feasible in a short time frame.
    
-
    Testing, Security, and Privacy
    
+
    Testing, Security, and Privacy
    
 
    The main security consideration concerns the size of replies and the resources necessary to generate them. It is for example easily possible to ask for all keys and values of the chain, which would take a very long time to generate. Since responses to this networking protocol have a maximum size, the replier should truncate proofs that would lead to the response being too large. Note that it is already possible to send a query that would lead to a very large reply with the existing network protocol. The only thing that this proposal changes is that it would make it less complicated to perform such an attack.
    
 
    Implementers of the replier side should be careful to detect early on when a reply would exceed the maximum reply size, rather than inconditionally generate a reply, as this could take a very large amount of CPU, disk I/O, and memory. Existing implementations might currently be accidentally protected from such an attack thanks to the fact that requests have a maximum size, and thus that the list of keys in the query was bounded. After this proposal, this accidental protection would no longer exist.
    
 
    Malicious server nodes might truncate Merkle proofs even when they don't strictly need to, and it is not possible for the client to (easily) detect this situation. However, malicious server nodes can already do undesirable things such as throttle down their upload bandwidth or simply not respond. There is no need to handle unnecessarily truncated Merkle proofs any differently than a server simply not answering the request.
    
-
    Performance, Ergonomics, and Compatibility
    
-
    Performance
    
+
    Performance, Ergonomics, and Compatibility
    
+
    Performance
    
 
    It is unclear to the author of the RFC what the performance implications are. Servers are supposed to have limits to the amount of resources they use to respond to requests, and as such the worst that can happen is that light client requests become a bit slower than they currently are.
    
-
    Ergonomics
    
+
    Ergonomics
    
 
    Irrelevant.
    
-
    Compatibility
    
+
    Compatibility
    
 
    The prior networking protocol is maintained for now. The older version of this protocol could get removed in a long time.
    
-
    Prior Art and References
    
+
    Prior Art and References
    
 
    None. This RFC is a clean-up of an existing mechanism.
    
-
    Unresolved Questions
    
+
    Unresolved Questions
    
 
    None
    
-
+
 
    The current networking protocol could be deprecated in a long time. Additionally, the current "state requests" protocol (used for warp syncing) could also be deprecated in favor of this one.
    
 
    (source)
    
 
    Table of Contents
    
@@ -2047,13 +1632,13 @@ Also note that child tries aren't considered as descendants of the main trie whe
 AuthorsJonas Gehrlein
 
 
-
    Summary
    
+
    Summary
    
 
    The Polkadot UC will generate revenue from the sale of available Coretime. The question then arises: how should we handle these revenues? Broadly, there are two reasonable paths – burning the revenue and thereby removing it from total issuance or divert it to the Treasury. This Request for Comment (RFC) presents arguments favoring burning as the preferred mechanism for handling revenues from Coretime sales.
    
-
    Motivation
    
+
    Motivation
    
 
    How to handle the revenue accrued from Coretime sales is an important economic question that influences the value of DOT and should be properly discussed before deciding for either of the options. Now is the best time to start this discussion.
    
-
    Stakeholders
    
+
    Stakeholders
    
 
    Polkadot DOT token holders.
    
-
    Explanation
    
+
    Explanation
    
 
    This RFC discusses potential benefits of burning the revenue accrued from Coretime sales instead of diverting them to Treasury. Here are the following arguments for it.
    
 
    It's in the interest of the Polkadot community to have a consistent and predictable Treasury income, because volatility in the inflow can be damaging, especially in situations when it is insufficient. As such, this RFC operates under the presumption of a steady and sustainable Treasury income flow, which is crucial for the Polkadot community's stability. The assurance of a predictable Treasury income, as outlined in a prior discussion here, or through other equally effective measures, serves as a baseline assumption for this argument. 
    
 
    Consequently, we need not concern ourselves with this particular issue here. This naturally begs the question - why should we introduce additional volatility to the Treasury by aligning it with the variable Coretime sales? It's worth noting that Coretime revenues often exhibit an inverse relationship with periods when Treasury spending should ideally be ramped up. During periods of low Coretime utilization (indicated by lower revenue), Treasury should spend more on projects and endeavours to increase the demand for Coretime. This pattern underscores that Coretime sales, by their very nature, are an inconsistent and unpredictable source of funding for the Treasury. Given the importance of maintaining a steady and predictable inflow, it's unnecessary to rely on another volatile mechanism. Some might argue that we could have both: a steady inflow (from inflation) and some added bonus from Coretime sales, but burning the revenue would offer further benefits as described below.
    
@@ -2096,13 +1681,13 @@ Also note that child tries aren't considered as descendants of the main trie whe
 AuthorsJoe Petrowski
 
 
-
    Summary
    
+
    Summary
    
 
    Since the introduction of the Collectives parachain, many groups have expressed interest in forming
 new -- or migrating existing groups into -- on-chain collectives. While adding a new collective is
 relatively simple from a technical standpoint, the Fellowship will need to merge new pallets into
 the Collectives parachain for each new collective. This RFC proposes a means for the network to
 ratify a new collective, thus instructing the Fellowship to instate it in the runtime.
    
-
    Motivation
    
+
    Motivation
    
 
    Many groups have expressed interest in representing collectives on-chain. Some of these include:
    
 
-
    Drawbacks
    
+
    Drawbacks
    
 
    Other than all other system chains, development and maintenance of the Encointer Network is mainly financed by the KSM Treasury and possibly the DOT Treasury in the future. Encointer is dedicated to maintaining its network and runtime code for as long as possible, but there is a dependency on funding which is not in the hands of the fellowship. The only risk in the context of funding, however, is that the Encointer runtime will see less frequent updates if there's less funding. 
    
-
    Testing, Security, and Privacy
    
+
    Testing, Security, and Privacy
    
 
    No changes to the existing system are proposed. Only changes to how maintenance is organized.
    
-
    Performance, Ergonomics, and Compatibility
    
+
    Performance, Ergonomics, and Compatibility
    
 
    No changes
    
-
    Prior Art and References
    
+
    Prior Art and References
    
 
    Existing Encointer runtime repo
    
-
    Unresolved Questions
    
+
    Unresolved Questions
    
 
    None identified
    
-
+
 
    More info on Encointer: encointer.org
    
 
    (source)
    
 
    Table of Contents
    
@@ -3394,11 +2979,11 @@ other privacy-enhancing mechanisms to address this concern.
 AuthorsJoe Petrowski, Gavin Wood
 
 
-
    Summary
    
+
    Summary
    
 
    The Relay Chain contains most of the core logic for the Polkadot network. While this was necessary
 prior to the launch of parachains and development of XCM, most of this logic can exist in
 parachains. This is a proposal to migrate several subsystems into system parachains.
    
-
    Motivation
    
+
    Motivation
    
 
    Polkadot's scaling approach allows many distinct state machines (known generally as parachains) to
 operate with common guarantees about the validity and security of their state transitions. Polkadot
 provides these common guarantees by executing the state transitions on a strict subset (a backing
@@ -3410,13 +2995,13 @@ blockspace) to the network.
    
 
    By minimising state transition logic on the Relay Chain by migrating it into "system chains" -- a
 set of parachains that, with the Relay Chain, make up the Polkadot protocol -- the Polkadot
 Ubiquitous Computer can maximise its primary offering: secure blockspace.
    
-
    Stakeholders
    
+
    Stakeholders
    
 
      
 
    • Parachains that interact with affected logic on the Relay Chain;
      • 
 
    • Core protocol and XCM format developers;
      • 
 
    • Tooling, block explorer, and UI developers.
      • 
 
    
-
    Explanation
    
+
    Explanation
    
 
    The following pallets and subsystems are good candidates to migrate from the Relay Chain:
    -

    Drawbacks

    +

    Drawbacks

    There should be no drawbacks as it would replace state_version with same behavior but documentation should be updated so that chains know which system_version to use.

    -

    Testing, Security, and Privacy

    +

    Testing, Security, and Privacy

    AFAIK, should not have any impact on the security or privacy.

    -

    Performance, Ergonomics, and Compatibility

    +

    Performance, Ergonomics, and Compatibility

    These changes should be compatible for existing chains if they use state_version value for system_verision.

    -

    Performance

    +

    Performance

    I do not believe there is any performance hit with this change.

    -

    Ergonomics

    +

    Ergonomics

    This does not break any exposed Apis.

    -

    Compatibility

    +

    Compatibility

    This change should not break any compatibility.

    -

    Prior Art and References

    +

    Prior Art and References

    We proposed introducing a similar change by introducing a parameter to frame_system::Config but did not feel that is the correct way of introducing this change.

    -

    Unresolved Questions

    +

    Unresolved Questions

    I do not have any specific questions about this change at the moment.

    - +

    IMO, this change is pretty self-contained and there won't be any future work necessary.

    (source)

    Table of Contents

    @@ -3722,9 +3307,9 @@ is the correct way of introducing this change.

    AuthorsSebastian Kunert -

    Summary

    +

    Summary

    This RFC proposes a new host function for parachains, storage_proof_size. It shall provide the size of the currently recorded storage proof to the runtime. Runtime authors can use the proof size to improve block utilization by retroactively reclaiming unused storage weight.

    -

    Motivation

    +

    Motivation

    The number of extrinsics that are included in a parachain block is limited by two constraints: execution time and proof size. FRAME weights cover both concepts, and block-builders use them to decide how many extrinsics to include in a block. However, these weights are calculated ahead of time by benchmarking on a machine with reference hardware. The execution-time properties of the state-trie and its storage items are unknown at benchmarking time. Therefore, we make some assumptions about the state-trie:

     Transact Over Bridge -

    Drawbacks

    +

    Drawbacks

    In terms of ergonomics and user experience, this support for combining an asset transfer with a subsequent action (like Transact) is a net positive.

    In terms of performance, and privacy, this is neutral with no changes.

    In terms of security, the feature by itself is also neutral because it allows preserve_origin: false usage for operating with no extra trust assumptions. When wanting to support preserving origin, chains need to configure secure origin aliasing filters. The one suggested in this RFC should be the right choice for the majority of chains, but each chain will ultimately choose depending on their business model and logic (e.g. chain does not plan to integrate with Asset Hub). It is up to the individual chains to configure accordingly.

    -

    Testing, Security, and Privacy

    +

    Testing, Security, and Privacy

    Barriers should now allow AliasOrigin, DescendOrigin or ClearOrigin.

    Normally, XCM program builders should audit their programs and eliminate assumptions of "no origin" on remote side of this instruction. In this case, the InitiateAssetsTransfer has not been released yet, it will be part of XCMv5, and we can make this change part of the same XCMv5 so that there isn't even the possibility of someone in the wild having built XCM programs using this instruction on those wrong assumptions.

    The working assumption going forward is that the origin on the remote side can either be cleared or it can be the local origin's reanchored location. This assumption is in line with the current behavior of remote XCM programs sent over using pallet_xcm::send.

    The existing DepositReserveAsset, InitiateReserveWithdraw and InitiateTeleport cross chain asset transfer instructions will not attempt to do origin aliasing and will always clear origin same as before for compatibility reasons.

    -

    Performance, Ergonomics, and Compatibility

    -

    Performance

    +

    Performance, Ergonomics, and Compatibility

    +

    Performance

    No impact.

    -

    Ergonomics

    +

    Ergonomics

    Improves ergonomics by allowing the local origin to operate on the remote chain even when the XCM program includes an asset transfer.

    -

    Compatibility

    +

    Compatibility

    At the executor-level this change is backwards and forwards compatible. Both types of programs can be executed on new and old versions of XCM with no changes in behavior.

    New version of the InitiateAssetsTransfer instruction acts same as before when used with preserve_origin: false.

    For using the new capabilities, the XCM builder has to verify that the involved chains have the required origin-aliasing filters configured and use some new version of Barriers aware of AliasOrigin as an allowed alternative to ClearOrigin.

    For compatibility reasons, this RFC proposes this mechanism be added as an enhancement to the yet unreleased InitiateAssetsTransfer instruction, thus eliminating possibilities of XCM logic breakages in the wild. Following the same logic, the existing DepositReserveAsset, InitiateReserveWithdraw and InitiateTeleport cross chain asset transfer instructions will not attempt to do origin aliasing and will always clear the origin same as before for compatibility reasons.

    Any one of DepositReserveAsset, InitiateReserveWithdraw and InitiateTeleport instructions can be replaced with a InitiateAssetsTransfer instruction with or without origin aliasing, thus providing a clean and clear upgrade path for opting-in this new feature.

    -

    Prior Art and References

    +

    Prior Art and References

    -

    Unresolved Questions

    +

    Unresolved Questions

    None

    - +

    (source)

    Table of Contents