Proxyd

proxyd is an RPC proxy

• https://github.com/ethereum-optimism/infra/tree/main/proxyd

proxyd /etc/proxyd/proxyd.toml 

Features:

• Whitelists RPC methods
• Routes RPC methods to groups of backend services
• Load balance requests across backend services
• Automatically retries failed backend requests
• Cache immutable responses from backends
• Provides metrics to measure request latency, error rates

Consensus related:

• Track backend consensus (latest, safe, finalized blocks), peer count and sync state
• Re-write requests and responses to enforce consensus

• Applies rate limiting on a per-sender basis to avoid being bombarded with signed transactions causing a DOS (Denial of Service) of the sequencer (Optimism Censorship Bug Disclosure)

Logs

ERROR

• Error forwarding RPC batch
• error forwarding request to backend
• error proxying websocket
• error writing clientConn message
• error serving requests

WARN

• backend request failed, trying again
• backend banned - not healthy
• backend banned - unexpected block tags
• proxied requests' XFF header will not contain the proxyd ip address
• peer count responded with 200 and 0 peers
• failed request
• error updating backend
• backend broke consensus

INFO

• starting proxyd
• Updating CA certificates.
• Running CMD.

Related

• Consensus
• Emerald Dshackle load balancer
• dRPC
• Total number of primary candidates
• Optimism Censorship Bug Disclosure

See also

• proxyd, consensus_aware, SenderRateLimitConfig
• OP Stack: op-, op-geth, op-node, op-proposer, op-batcher, op-contracts, op-challenger, op-heartbeat, op-ufm, op-service, Snap Sync