frame: remove finality-tracker

[andresilva]

The initial idea was to use the finality-tracker module to automatically trigger GRANDPA's offline fallback. Due to efficiency concerns the module currently only allows tracking finality over short periods (e.g. last 100 blocks), which is too little to act automatically on. Furthermore, we recently added #6725 which instead allows us to trigger GRANDPA's offline fallback manually through governance which is a lot safer (and preferred). Removing this as suggested in #6725 (comment).

polkadot companion: paritytech/polkadot#1762

[andresilva]

It should be fine to remove the inherent provider right away since the runtime module already expects that inherent data about finalized number might not be available.

[andresilva]

Found an issue during burnin, needs some changes.

[kianenigma]

What issues? I was actually wondering what issue could possibly arise from removal of a pallet that you did a burnin.

[andresilva]

@kianenigma Since other nodes are still adding the inherent data the node will fail to decode those inherents that come in the block.

Oct 09 15:52:12 kusama-sentry-ew1-1 kusama[27879]: Oct 09 15:52:12.155  WARN 💔 Verification failed for block 0x5228ee456ee78813978d5cd0000af129bf32e719f27daa3b1530835a12f6319b received from peer: 12D3KooWAHbuhp5pq8uFeLwDBbxNWd1qtjGS95z3XVuseZ9nJDHS, "Execution: Could not convert parameter `block` between node and runtime: Error decoding field Block.extrinsics"

Still not sure about what to do since for historical blocks these inherents will always exist.

[bkchr]

@kianenigma Since other nodes are still adding the inherent data the node will fail to decode those inherents that come in the block.

Oct 09 15:52:12 kusama-sentry-ew1-1 kusama[27879]: Oct 09 15:52:12.155  WARN 💔 Verification failed for block 0x5228ee456ee78813978d5cd0000af129bf32e719f27daa3b1530835a12f6319b received from peer: 12D3KooWAHbuhp5pq8uFeLwDBbxNWd1qtjGS95z3XVuseZ9nJDHS, "Execution: Could not convert parameter `block` between node and runtime: Error decoding field Block.extrinsics"

Still not sure about what to do since for historical blocks these inherents will always exist.

Wait. That means you don't have bumped the spec_version.

[kianenigma]

I guess historical blocks will be fine because a historical runtime will also have this pallet? The problem seem more like that this PR is kinda hard to burn-in in the public, because of what you said: other nodes will produce blocks with the inherent while your node will reject.

[andresilva]

@kianenigma Since other nodes are still adding the inherent data the node will fail to decode those inherents that come in the block.

Oct 09 15:52:12 kusama-sentry-ew1-1 kusama[27879]: Oct 09 15:52:12.155  WARN 💔 Verification failed for block 0x5228ee456ee78813978d5cd0000af129bf32e719f27daa3b1530835a12f6319b received from peer: 12D3KooWAHbuhp5pq8uFeLwDBbxNWd1qtjGS95z3XVuseZ9nJDHS, "Execution: Could not convert parameter `block` between node and runtime: Error decoding field Block.extrinsics"

Still not sure about what to do since for historical blocks these inherents will always exist.

Wait. That means you don't have bumped the spec_version.

Yeah, I'm an idiot 🤦. @kianenigma disregard what I said.

[andresilva]

Burn-in done, no issues found.

[andresilva]

bot merge

[ghost]

Trying merge.