How can I get my parachain to produce blocks? (sanity checklist)

Question

On launch of a parachain it can be a challenge to debug why a parachain cannot produce blocks.

List answers as to what to look for and sanity checks for debugging a parachain that cannot produce blocks on launch.

Answer 1

The common sanity checks are:

1. Check that the genesis-head-state which you submitted in your parathread and the parachain-genesis-state that shows on your parachain logs are the same. If they aren't the same then you may have create your genesis-head with the incorrect para-id. To fix that you need to check the chain spec and make sure you change para-id and parachain-id to the correct number that you registered on the relay chain.

The parachain-genesis-state is shared below:

2022-02-11 12:56:16 Parachain Collator Template    
2022-02-11 12:56:16 ✌️  version 0.1.0-a1e5a62-x86_64-linux-gnu    
2022-02-11 12:56:16 ❤️  by Anonymous, 2020-2022    
2022-02-11 12:56:16 📋 Chain specification: Local Testnet    
2022-02-11 12:56:16 🏷  Node name: Alice    
2022-02-11 12:56:16 👤 Role: AUTHORITY    
2022-02-11 12:56:16 💾 Database: RocksDb at /tmp/parachain/alice/chains/local_testnet/db/full    
2022-02-11 12:56:16 ⛓  Native runtime: template-parachain-1 (template-parachain-0.tx0.au1)    
2022-02-11 12:56:16 Parachain id: Id(2001)    
2022-02-11 12:56:16 Parachain Account: 5Ec4AhPV91i9yNuiWuNunPf6AQCYDhFTTA4G5QCbtqYApH9E    
2022-02-11 12:56:16 Parachain genesis state: 0x000000000000000000000000000000000000000000000000000000000000000000621973be15d1cb405a885c5fd46c89f10d8d95832023efc847e6d7df8c1b18a403170a2e7597b7b7e3d84c05391d139a62b157e78786d8c082f29dcf4c11131400    
2022-02-11 12:56:16 Is collating: yes   

2. If you are connecting to a public testnet or live chain, make sure that the chain type is set to Live.

3. Make sure that if you added more than one collator to your chain spec that you launch all the expected collators.

4. Check that your ports are open.

5. Make sure that when you re-launch a collator you also clear the tmp db which you created with your --base-path tag.

6. Make sure the collator keys are registered and are the same as in the chain-spec.

Answer 2

For me building up from the basics:

1. Is there network traffic or does it say 0 up 0 down?
2. Can it see peers?

(This answer is work in progress)