No Peer Down after hold timer expires

[veMfoaXQ]

Version

GoBGP v2.10.0

Description

After a hold timer expires for a peer, GoBGP does not consider a peer to be down. In the following log, I expect to see Peer Down after 2024-04-24T17:37:12.600Z, but there isn't one.

2024-04-24T17:37:12.600Z time="2024-04-24T17:37:12Z" level=warning msg="hold timer expired" Key=1.1.1.1 State=BGP_FSM_ESTABLISHED Topic=Peer
2024-04-24T17:37:12.600Z time="2024-04-24T17:37:12Z" level=warning msg="received notification" Code=4 Data="[]" Key=1.1.1.1 Subcode=0 Topic=Peer
2024-04-24T17:37:12.600Z time="2024-04-24T17:37:12Z" level=warning msg="sent notification" Code=4 Data="[]" Key=1.1.1.1 State=BGP_FSM_ESTABLISHED Subcode=0 Topic=Peer
2024-04-24T17:22:27.933Z time="2024-04-24T17:22:27Z" level=info msg="Peer Up" Key=1.1.1.1 State=BGP_FSM_OPENCONFIRM Topic=Peer
2024-04-24T17:22:12.931Z time="2024-04-24T17:22:11Z" level=info msg="Peer Down" Key=1.1.1.1 Reason=hold-timer-expired State=BGP_FSM_ESTABLISHED Topic=Peer
2024-04-24T17:22:11.931Z time="2024-04-24T17:22:11Z" level=warning msg="hold timer expired" Key=1.1.1.1 State=BGP_FSM_ESTABLISHED Topic=Peer
2024-04-24T17:22:11.931Z time="2024-04-24T17:22:11Z" level=warning msg="sent notification" Code=4 Data="[]" Key=1.1.1.1 State=BGP_FSM_ESTABLISHED Subcode=0 Topic=Peer
2024-04-24T08:29:12.090Z time="2024-04-24T08:29:11Z" level=info msg="Neighbor soft reset in" Key=1.1.1.1 Topic=Operation
2024-04-24T08:27:41.797Z time="2024-04-24T08:27:41Z" level=info msg="Neighbor soft reset in" Key=1.1.1.1 Topic=Operation
2024-04-24T00:39:27.042Z time="2024-04-24T00:39:26Z" level=info msg="Neighbor soft reset in" Key=1.1.1.1 Topic=Operation
2024-04-24T00:38:56.776Z time="2024-04-24T00:38:56Z" level=info msg="Neighbor soft reset in" Key=1.1.1.1 Topic=Operation

GoBGP then starts accumulating outgoing BGP messages in the peer's message queue, until it eventually runs out of memory and crashes. I have verified by extending a gRPC API endpoint to expose the length of the queue for each peer's FSM, and periodically calling it.