Troubleshooting

Start with the failing plane: P2P sync, local storage, gRPC, GraphQL, or client behavior.

Symptom	First checks
Node behind network	Peer count, P2P port 8080, disk I/O, checkpoint logs.
gRPC unavailable	Listener on 9000, HTTP/2 load balancer support, health script.
GraphQL slow	Query depth, pagination size, gateway cache, checkpoint lag.
Event indexer gaps	Last committed checkpoint, stream reconnect logs, Postgres transaction errors.
Transaction submission failures	Serialized bytes, signatures, gas object state, TransactionExecutionService errors.

Use the sample scripts as black-box checks before changing configuration.