# NeuroWeb - Swap issue

## What happened
NeuroWeb, previously known as OriginTrail, intended to extend their lease on Polkadot by performing a swap with another paraID of their own. The active lease from NeuroWeb was valid until the end of LP15, whilst the new paraID they got (paraID 3360) had a lease valid from the start of LP16. The objective was to swap these leases at the very end of LP15 to minimize downtime (expected to be ~2 minutes). Although [the swap was successful](https://polkadot.subscan.io/extrinsic/20275187-4?event=20275187-62) and the active paraID managed to get the lease extended, this also made the parachain to start a downgrading process.

The end result was that the active parachain had the new leases but it was not a parachain anymore, whilst the new paraID did not have any leases but it was a parachain.

At block 20_279_472, [`slots.triggerOnboard` was executed](https://polkadot.subscan.io/extrinsic/20279472-2) and paraID 2043 started the onboarding period, which is expected to be completed at around 17:35pm CET. This resulted in 8hs of downtime for paraID 2043.

### Tests
Before actually performing the swaps, the NeuroWeb team had executed this with Chopsticks and everything worked as expected. They claimed that they have not seen any downgrading or upgrading process in their tests.

## Backup plans
It's expected that NeuroWeb resumes their block production at 17:35 CET on April 10th 2024. If this was not to be the case, then governance action will be required to fix the underlying issue, still unknown. It most probably have to be a `slots.forceLease`, or another `swap` back between the two para IDs. As this will take some time, actions for the team to continue producing blocks are:
1. Swap their now active paraID (3360) with a team that's not using it's parachain.
- Potential candidates are BitGreen, OAK Network and OmniBTC. These teams need to accept the swap, and have all been contacted by success to gauge their interest - pending responses
- NeuroWeb to execute a runtime upgrade on 3360 to run the right code.
- NeuroWeb to set a head on 3360 according to the last parablock they had on their previous chain.
- Potentially takes more time to convince everyone.
2. Continue producing blocks on Kusama instead of Polkadot.
- Would require to get a team to give their slot to NeuroWeb. Candidate is GM Parachain.
- NeuroWeb needs to accept to continue block production on Kusama.
- Execute same migration as KILT and Subsocial, but on the other direction.
- Could be done quite fast.

## Result
None of the backup plans where necesarry. Once the two sessions were completed, Origin Trail resumed block production.

## Future avoidance
This is the result of having to swap paraIDs on Polkadot given some of the limitations of the slot-based model. Basically teams that wanted to renew their slot by doing a new crowdloan where forced to get a new ParaID. When these periods (old and new) where adjacent one to the other, then this downtime would happen.

With the core-based model, swapping functionality ceases to exist, as it's not needed, so this is not to be expected anymore.