Description

When connecting to the /eth/v1/events event stream, clients will get unexpected disconnections from the lighthouse beacon node. Especially on the attestation topic for mainnet while subscribing all subnets.

Version

Rust - 1.69.0 (84c898d65 2023-04-16)
unstable - commit 7456e1e8faac7a581705f8e71b0dc4f09a36ee5c
stable - commit 693886b94176faa4cb450f024696cb69cda2fe58

Present Behaviour

To replicate the current behaviour easily connect via curl;

curl "http://127.0.0.1:5052/eth/v1/events?topics=attestation" -H "accept: text/event-stream"

Eventually you'll get disconnected with the libcurl error;

curl: (18) transfer closed with outstanding read data remaining

If you want to speed this up run the beacon node with --subscribe-all-subnets --import-all-attestations flags on mainnet to have more attestation events published. With a "fast" machine you will get disconnected multiple times a slot.

Expected Behaviour

Should not disconnect unexpectedly.