Use dynamic aura slot duration in lookahead collator (#3211)
It's a follow-up of #2949. It enables the lookahead collator to dynamically adjust the aura slot size, which may change during the runtime upgrade. It also addressed a couple of issues with time constants I missed in the original PR. Good news: it works. The parachain successfully switches from sync backing with 12s slots to async backing with 6s slots. Bad news: during the transitional period of a single block in which the actual runtime upgrade is performed, it still gets the old slot duration of 12s (as it gets it from the best block), resulting in a runtime panic (logs follow). That doesn't affect the following block production of the parachain. Ideas on how to improve the situation are appreciated. <details> ``` 2024-02-05 12:59:36.373 INFO tokio-runtime-worker sc_basic_authorship::basic_authorship: [Parachain]🙌 Starting consensus session on top of parent 0x6fd2d8f904f12c22531bfabf77b16dc84a6a29e45d9ae358aa6547fbf3f0438b 2024-02-05 12:59:36.373 ERROR tokio-runtime-worker runtime: [Parachain] panicked at /home/s0me0ne/wrk/parity/polkadot-sdk/cumulus/pallets/aura-ext/src/consensus_hook.rs:69:9: assertion `left == right` failed: slot number mismatch left: Slot(142261198) right: Slot(284522396) 2024-02-05 12:59:36.373 WARN tokio-runtime-worker sp_state_machine::overlayed_changes::changeset: [Parachain] 1 storage transactions are left open by the runtime. Those will be rolled back. 2024-02-05 12:59:36.373 WARN tokio-runtime-worker sp_state_machine::overlayed_changes::changeset: [Parachain] 1 storage transactions are left open by the runtime. Those will be rolled back. 2024-02-05 12:59:36.373 WARN tokio-runtime-worker basic-authorship: [Parachain]❗ Inherent extrinsic returned unexpected error: Error at calling runtime api: Execution failed: Execution aborted due to trap: wasm trap: wasm `unreachable` instruction executed WASM backtrace: error while executing at wasm backtrace: 0: 0x4e4a3b - <unknown>!rust_begin_unwind 1: 0x46cf57 - <unknown>!core::panicking::panic_fmt::h3c280dba88683724 2: 0x46d238 - <unknown>!core::panicking::assert_failed_inner::hebac5970933beb4d 3: 0x3d00fc - <unknown>!core::panicking::assert_failed::h640a47e2fb5dfb4b 4: 0xd0db3 - <unknown>!frame_support::storage::transactional::with_transaction::hcbc31515f81b2ee1 5: 0x34d654 - <unknown>!<cumulus_pallet_parachain_system::pallet::Call<T> as frame_support::traits::dispatch::UnfilteredDispatchable>::dispatch_bypass_filter::{{closure}}::hb7c2c9a11fa88301 6: 0x3547db - <unknown>!environmental::local_key::LocalKey<T>::with::h783f2605ae27d6d3 7: 0x7f454 - <unknown>!<asset_hub_rococo_runtime::RuntimeCall as frame_support::traits::dispatch::UnfilteredDispatchable>::dispatch_bypass_filter::h5e11a01ab97c06c7 8: 0x7f237 - <unknown>!<asset_hub_rococo_runtime::RuntimeCall as sp_runtime::traits::Dispatchable>::dispatch::h7f8ae4a8fede71ca 9: 0x26a0f3 - <unknown>!frame_executive::Executive<System,Block,Context,UnsignedValidator,AllPalletsWithSystem,COnRuntimeUpgrade>::apply_extrinsic::h75e524ff34738391 10: 0x282211 - <unknown>!BlockBuilder_apply_extrinsic. Dropping. 2024-02-05 12:59:36.374 ERROR tokio-runtime-worker runtime: [Parachain] panicked at /home/s0me0ne/wrk/parity/polkadot-sdk/substrate/frame/aura/src/lib.rs:416:9: assertion `left == right` failed: Timestamp slot must match `CurrentSlot` left: Slot(142261198) right: Slot(284522396) 2024-02-05 12:59:36.374 WARN tokio-runtime-worker sp_state_machine::overlayed_changes::changeset: [Parachain] 1 storage transactions are left open by the runtime. Those will be rolled back. 2024-02-05 12:59:36.374 WARN tokio-runtime-worker sp_state_machine::overlayed_changes::changeset: [Parachain] 1 storage transactions are left open by the runtime. Those will be rolled back. 2024-02-05 12:59:36.374 WARN tokio-runtime-worker basic-authorship: [Parachain]❗ Inherent extrinsic returned unexpected error: Error at calling runtime api: Execution failed: Execution aborted due to trap: wasm trap: wasm `unreachable` instruction executed WASM backtrace: error while executing at wasm backtrace: 0: 0x4e4a3b - <unknown>!rust_begin_unwind 1: 0x46cf57 - <unknown>!core::panicking::panic_fmt::h3c280dba88683724 2: 0x46d238 - <unknown>!core::panicking::assert_failed_inner::hebac5970933beb4d 3: 0x3d00fc - <unknown>!core::panicking::assert_failed::h640a47e2fb5dfb4b 4: 0x9ece6 - <unknown>!frame_support::storage::transactional::with_transaction::h26f75cb9f9462088 5: 0x356d7e - <unknown>!environmental::local_key::LocalKey<T>::with::hbcf2d4e17b48fdb5 6: 0x7f507 - <unknown>!<asset_hub_rococo_runtime::RuntimeCall as frame_support::traits::dispatch::UnfilteredDispatchable>::dispatch_bypass_filter::h5e11a01ab97c06c7 7: 0x7f237 - <unknown>!<asset_hub_rococo_runtime::RuntimeCall as sp_runtime::traits::Dispatchable>::dispatch::h7f8ae4a8fede71ca 8: 0x26a0f3 - <unknown>!frame_executive::Executive<System,Block,Context,UnsignedValidator,AllPalletsWithSystem,COnRuntimeUpgrade>::apply_extrinsic::h75e524ff34738391 9: 0x282211 - <unknown>!BlockBuilder_apply_extrinsic. Dropping. 2024-02-05 12:59:36.374 DEBUG tokio-runtime-worker runtime::xcmp-queue-migration: [Parachain] Lazy migration finished: item gone 2024-02-05 12:59:36.374 ERROR tokio-runtime-worker runtime: [Parachain] panicked at /home/s0me0ne/wrk/parity/polkadot-sdk/cumulus/pallets/parachain-system/src/lib.rs:265:18: set_validation_data inherent needs to be present in every block! 2024-02-05 12:59:36.374 ERROR tokio-runtime-worker aura::cumulus: [Parachain] err=Error { inner: Proposing Caused by: 0: Error at calling runtime api: Execution failed: Execution aborted due to trap: wasm trap: wasm `unreachable` instruction executed WASM backtrace: error while executing at wasm backtrace: 0: 0x4e4a3b - <unknown>!rust_begin_unwind 1: 0x46cf57 - <unknown>!core::panicking::panic_fmt::h3c280dba88683724 2: 0x46da8b - <unknown>!core::option::expect_failed::hdf18d99c3adabca7 3: 0x2134cb - <unknown>!<cumulus_pallet_parachain_system::pallet::Pallet<T> as frame_support::traits::hooks::OnFinalize<<<<T as frame_system::pallet::Config>::Block as sp_runtime::traits::HeaderProvider>::HeaderT as sp_runtime::traits::Header>::Number>>::on_finalize::hf98aac39802896ba 4: 0x26a9d6 - <unknown>!frame_executive::Executive<System,Block,Context,UnsignedValidator,AllPalletsWithSystem,COnRuntimeUpgrade>::idle_and_finalize_hook::h32775c0df0749d92 5: 0x26ad9f - <unknown>!frame_executive::Executive<System,Block,Context,UnsignedValidator,AllPalletsWithSystem,COnRuntimeUpgrade>::finalize_block::h15e5a1a6b9ca8032 6: 0x2822bd - <unknown>!BlockBuilder_finalize_block 1: Execution failed: Execution aborted due to trap: wasm trap: wasm `unreachable` instruction executed WASM backtrace: error while executing at wasm backtrace: 0: 0x4e4a3b - <unknown>!rust_begin_unwind 1: 0x46cf57 - <unknown>!core::panicking::panic_fmt::h3c280dba88683724 2: 0x46da8b - <unknown>!core::option::expect_failed::hdf18d99c3adabca7 3: 0x2134cb - <unknown>!<cumulus_pallet_parachain_system::pallet::Pallet<T> as frame_support::traits::hooks::OnFinalize<<<<T as frame_system::pallet::Config>::Block as sp_runtime::traits::HeaderProvider>::HeaderT as sp_runtime::traits::Header>::Number>>::on_finalize::hf98aac39802896ba 4: 0x26a9d6 - <unknown>!frame_executive::Executive<System,Block,Context,UnsignedValidator,AllPalletsWithSystem,COnRuntimeUpgrade>::idle_and_finalize_hook::h32775c0df0749d92 5: 0x26ad9f - <unknown>!frame_executive::Executive<System,Block,Context,UnsignedValidator,AllPalletsWithSystem,COnRuntimeUpgrade>::finalize_block::h15e5a1a6b9ca8032 6: 0x2822bd - <unknown>!BlockBuilder_finalize_block } ``` </details> --------- Co-authored-by:Bastian Köcher <[email protected]>