parachain full node stops sync with parachain. finalized stays at zero

Question

We're running a full node for a parachain based on PSDK-1.13. At startup, both relay and para are catching up nicely and at some point are in sync.

Then, the relay keeps syncing, but the para block import stalls. Stalling means we see this forever

[Parachain] ⚙️  Preparing  0.0 bps, target=#6221653 (10 peers), best: #6221647 (0x7563…1851), finalized #0 (0xcded…58da), ⬇ 58 B/s ⬆ 0.3kiB/s

noteworthy:

finalized: 0 (but the para actually finalizes fine and continues producing blocks)
reproducible: restarting will again catch up and then stall

Logs with -lsync=trace,network=debug

clangenb · Accepted Answer · 2024-10-17 07:28:46Z

This is related to https://github.com/paritytech/polkadot-sdk/issues/4903, which basically means you can't sync a reasonably sized para from scratch as resolving forks in the fork tree becomes way too expensive.

It has been resolved by https://github.com/paritytech/polkadot-sdk/pull/4922, which means that upgrading the collator binary to >= polkadot-v1.14.1 will resolve the issue.

A short term remedy would be to copy a synced para db to the collator you are trying to sync.

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