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Coretime Troubleshooting FAQ

This page aims to cover and aggregate various resources that relate to troubleshooting common problems when using the Polkadot SDK or deploying on a core.

FAQ / Troubleshooting

Why do I have to sync Rococo locally? Can't I just use a remote, trusted node and connect to that?

A: You can remotely connect to Rococo network via the --relay-chain-rpc-urls flag, which can be passed to your node. Unfortunately, the caveat is you can't use this node for collation at this time - meaning if you intend on being a collator/validator for your blockchain and intend to create blocks, you need to sync the chain locally.

Is there a faster way to sync Rococo? Why not warp sync?

A: Warp sync is currently not possible on Rococo or Westend. See this answer for more context.. However, --chain=rococo—-sync fast-unsafe should provide a faster way to sync with the relay chain by skipping downloading state proofs and just verifying the block headers.

My collator is not producing blocks

A: Check these sanity checklists:

I want to run more than one collator, how do I do that?

A: Ideally, you would want to run these on separate machines/servers, but you could as long as you ensure you can provide different RPC/WebSocket and P2P ports for each collator. You also may need to sync a separate instance of Rococo for each collator on the same machine. You also will need to choose the block production mechanism like Aura.

Why do we only have one collator in the parachain guides on the Wiki? Isn't it better to have more?

A: Mostly for simplicity. If we have more than one collator, we would have to also spin it up, which would be a hassle on a single machine (it is possible though). Of course, if you had an actual network with multiple collators, it is assumed you'd have separate VPS/servers for each.

Why are we registering parathreads and not parachains?

A: When registering a parachain on a relay chain, they are assigned a ParaID, and they are referred to as Parathreads till they start producing blocks. Parathreads are a bit of an outdated term now. They refer to what are now known as on-demand parachains. Although they be references in various places through PolkadotJS, docs, or other UIs, really we only have two types of parachain: on-demand parachains, and parachains which use bulk coretime.