Abstracts elections-phragmen pallet to use NposSolver #12588

gpestana · 2022-10-31T07:51:51Z

This PR refactors the current elections-phragmen pallet to use an NposSolver instead of hardcoding one flavor of phragmen. In addition, it implements an approval voting election scheme where each voter backs a limited set of candidates, without requiring splitting the stake among the selected candidates.

When using the pallet-elections, one should consider switching to a simpler NposSolver type like the approvals voting scheme, which is lighter than phragmen and reasonable in most cases. Users of this pallet should keep in mind that the election happens periodically on_initialize, and thus ensure that the election weight fits within a block (there is an integrity test to ensure the runtime configs comply).

Note that, although this PR renamed the old pallet-elections-phragmen to pallet-elections, the pallet name in the runtimes did not change in order to avoid a runtime upgrade (we could use move_pallet but that's not recommended). Otherwise a runtime upgrade would have been required.

Finally, this PR removes the need for a separate benchmarking crate for elections-provider-support. This way, it is possible to use the CI bench bot to correctly calculate and commit weights (all changes related to this merged and more info about it in this PR #13431).

rename elections-phragmen to elections-generic
change name of the pallet's dir from elections-phragmen to elections
comments on changing the name of the pallet (but not the lockid)
implement an approval voting election algorithm and NposSolver wrapper (WIP Implements approval voting to use as a NposSolver #13367)
refactor election-provider-support benchmarking and update pallet and runtime weights with CI bench bot.
~~try with follow-chain on a block that performs a council election~~

polkadot companion: paritytech/polkadot#6278

Closes #8250
Follow up of #12563

frame/elections-phragmen/src/lib.rs

kianenigma

Looks broadly good. Now we need to think about deployment: If we change the prefix of the pallet in construct_runtime!, then the whole pallet storage needs to be moved to the new prefix name.

So I see a few action items:

We should provide that migration script for simplicity.
There should be a clear update note on the PR stating that any chain has two options:

rename the pallet and run the migratin
keep the old pallet prefix in construct_runtime!

we should put the appropriate labels on the PR to make sure it goes into the release notes.
Would be good if we run this PR with follow-chain on a block that actually does a council election

and

a few housekeeping notes :D

as per contribution guide, avoiding force-pushes is advised.
label and project similarly advised

kianenigma · 2022-11-08T10:04:45Z

I think we should rename the pallet as well fwiw.

frame/elections-phragmen/src/lib.rs

kianenigma

The main challenge now is how you will reflect this change in making kitchensink-runtime compile, and next the polkadot companion.

Co-authored-by: Kian Paimani <[email protected]>

gpestana · 2022-11-08T22:26:30Z

I think we should rename the pallet as well fwiw.

Yes, was leaving that to the end. renaming now

gpestana · 2022-11-13T15:50:21Z

bot rebase

…lver

paritytech-processbot · 2023-02-21T11:43:30Z

Rebased

…13431) * Refactors election provider support benchmarks outside its own crate --------- Co-authored-by: command-bot <>

gpestana · 2023-02-23T09:45:38Z

bot rebase

paritytech-processbot · 2023-02-23T09:45:44Z

Branch is already up-to-date

gpestana · 2023-02-23T10:53:11Z

bot merge

paritytech-processbot · 2023-02-23T10:53:21Z

Error: Github API says paritytech/polkadot#6278 is not mergeable

gpestana · 2023-02-23T11:20:47Z

bot merge

frame/elections/src/lib.rs

This reverts commit 4be5dd2.

…" (#13451) This reverts commit 4be5dd2.

* Abstracts elections-phragmen pallet to use NposSolver * Update frame/elections-phragmen/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections-phragmen/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * changes the name of the pallet; adds changelog * update changelog * Adds weight testing * Adds log macro_rules * renames elections-phragment dir to elections * weights rename * fixes typo in cargo toml * pre/post solve weight scafolding * refactor do_post_election * refactors into pre and post election solve for independent benchmarking * deconstructs PreElectionResults struct * updates benchmarking pre and post election solve; mock weights * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * addresses PR comments * adds pre_solve and post_sove weights * Adds comments on election pallet id param name change * ".git/.scripts/bench-bot.sh" pallet dev pallet_elections * Finishes pre-post solve weights * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Addresses PR comments: no panic in on_init path; nits * Fixes node build * Implements approval voting to use as a `NposSolver` (paritytech#13367) * Implements the approval voting methods in sp_npos_elections * fmt * remove unecessary file * comment clarification * re-run weights * fix typo * updates MaxVoters in tests for integrity_tests to pass * Refactors election provider support benchmarks outside its own crate (paritytech#13431) * Refactors election provider support benchmarks outside its own crate --------- Co-authored-by: command-bot <> --------- Co-authored-by: Kian Paimani <[email protected]> Co-authored-by: parity-processbot <> Co-authored-by: Ross Bulat <[email protected]>

…tech#12588)" (paritytech#13451) This reverts commit 4be5dd2.

Polkadot-Forum · 2023-04-03T18:21:16Z

This pull request has been mentioned on Polkadot Forum. There might be relevant details there:

https://forum.polkadot.network/t/mis-configuring-pallet-elections-phragmen/2502/1

* Abstracts elections-phragmen pallet to use NposSolver * Update frame/elections-phragmen/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections-phragmen/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * changes the name of the pallet; adds changelog * update changelog * Adds weight testing * Adds log macro_rules * renames elections-phragment dir to elections * weights rename * fixes typo in cargo toml * pre/post solve weight scafolding * refactor do_post_election * refactors into pre and post election solve for independent benchmarking * deconstructs PreElectionResults struct * updates benchmarking pre and post election solve; mock weights * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * addresses PR comments * adds pre_solve and post_sove weights * Adds comments on election pallet id param name change * ".git/.scripts/bench-bot.sh" pallet dev pallet_elections * Finishes pre-post solve weights * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Addresses PR comments: no panic in on_init path; nits * Fixes node build * Implements approval voting to use as a `NposSolver` (paritytech#13367) * Implements the approval voting methods in sp_npos_elections * fmt * remove unecessary file * comment clarification * re-run weights * fix typo * updates MaxVoters in tests for integrity_tests to pass * Refactors election provider support benchmarks outside its own crate (paritytech#13431) * Refactors election provider support benchmarks outside its own crate --------- Co-authored-by: command-bot <> --------- Co-authored-by: Kian Paimani <[email protected]> Co-authored-by: parity-processbot <> Co-authored-by: Ross Bulat <[email protected]>

…tech#12588)" (paritytech#13451) This reverts commit 4be5dd2.

* Abstracts elections-phragmen pallet to use NposSolver * Update frame/elections-phragmen/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections-phragmen/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * changes the name of the pallet; adds changelog * update changelog * Adds weight testing * Adds log macro_rules * renames elections-phragment dir to elections * weights rename * fixes typo in cargo toml * pre/post solve weight scafolding * refactor do_post_election * refactors into pre and post election solve for independent benchmarking * deconstructs PreElectionResults struct * updates benchmarking pre and post election solve; mock weights * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * addresses PR comments * adds pre_solve and post_sove weights * Adds comments on election pallet id param name change * ".git/.scripts/bench-bot.sh" pallet dev pallet_elections * Finishes pre-post solve weights * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Addresses PR comments: no panic in on_init path; nits * Fixes node build * Implements approval voting to use as a `NposSolver` (paritytech#13367) * Implements the approval voting methods in sp_npos_elections * fmt * remove unecessary file * comment clarification * re-run weights * fix typo * updates MaxVoters in tests for integrity_tests to pass * Refactors election provider support benchmarks outside its own crate (paritytech#13431) * Refactors election provider support benchmarks outside its own crate --------- Co-authored-by: command-bot <> --------- Co-authored-by: Kian Paimani <[email protected]> Co-authored-by: parity-processbot <> Co-authored-by: Ross Bulat <[email protected]>

…tech#12588)" (paritytech#13451) This reverts commit 4be5dd2.

* Abstracts elections-phragmen pallet to use NposSolver * Update frame/elections-phragmen/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections-phragmen/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * changes the name of the pallet; adds changelog * update changelog * Adds weight testing * Adds log macro_rules * renames elections-phragment dir to elections * weights rename * fixes typo in cargo toml * pre/post solve weight scafolding * refactor do_post_election * refactors into pre and post election solve for independent benchmarking * deconstructs PreElectionResults struct * updates benchmarking pre and post election solve; mock weights * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * addresses PR comments * adds pre_solve and post_sove weights * Adds comments on election pallet id param name change * ".git/.scripts/bench-bot.sh" pallet dev pallet_elections * Finishes pre-post solve weights * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Addresses PR comments: no panic in on_init path; nits * Fixes node build * Implements approval voting to use as a `NposSolver` (paritytech#13367) * Implements the approval voting methods in sp_npos_elections * fmt * remove unecessary file * comment clarification * re-run weights * fix typo * updates MaxVoters in tests for integrity_tests to pass * Refactors election provider support benchmarks outside its own crate (paritytech#13431) * Refactors election provider support benchmarks outside its own crate --------- Co-authored-by: command-bot <> --------- Co-authored-by: Kian Paimani <[email protected]> Co-authored-by: parity-processbot <> Co-authored-by: Ross Bulat <[email protected]>

…tech#12588)" (paritytech#13451) This reverts commit 4be5dd2.

* Abstracts elections-phragmen pallet to use NposSolver * Update frame/elections-phragmen/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections-phragmen/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * changes the name of the pallet; adds changelog * update changelog * Adds weight testing * Adds log macro_rules * renames elections-phragment dir to elections * weights rename * fixes typo in cargo toml * pre/post solve weight scafolding * refactor do_post_election * refactors into pre and post election solve for independent benchmarking * deconstructs PreElectionResults struct * updates benchmarking pre and post election solve; mock weights * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * addresses PR comments * adds pre_solve and post_sove weights * Adds comments on election pallet id param name change * ".git/.scripts/bench-bot.sh" pallet dev pallet_elections * Finishes pre-post solve weights * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Update frame/elections/src/lib.rs Co-authored-by: Kian Paimani <[email protected]> * Addresses PR comments: no panic in on_init path; nits * Fixes node build * Implements approval voting to use as a `NposSolver` (paritytech#13367) * Implements the approval voting methods in sp_npos_elections * fmt * remove unecessary file * comment clarification * re-run weights * fix typo * updates MaxVoters in tests for integrity_tests to pass * Refactors election provider support benchmarks outside its own crate (paritytech#13431) * Refactors election provider support benchmarks outside its own crate --------- Co-authored-by: command-bot <> --------- Co-authored-by: Kian Paimani <[email protected]> Co-authored-by: parity-processbot <> Co-authored-by: Ross Bulat <[email protected]>

…tech#12588)" (paritytech#13451) This reverts commit 4be5dd2.

gpestana requested a review from kianenigma as a code owner October 31, 2022 07:51

gpestana self-assigned this Oct 31, 2022

github-actions bot added the A0-please_review Pull request needs code review. label Oct 31, 2022

gpestana marked this pull request as draft October 31, 2022 08:03

gpestana marked this pull request as ready for review October 31, 2022 08:03

Abstracts elections-phragmen pallet to use NposSolver

b714023

gpestana force-pushed the gpestana8250_npossolver branch from dbe65b8 to b714023 Compare October 31, 2022 08:28